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The rehabilitation of buildings: report on the Second Canadian Building Congress, Toronto, 15-17 October, 1979

THE REHABILITATION OF BUILDINGS:

REPORT ON THE SECOND CANADIAN BUILDING CONGRESS by

Andrew H. Wilson

PREFACE

This Congress - the first large one to be held in Canada on the subject of building rehabilitation - provided a richness of material that deserves wide dissemination. The published Proceedings are also substantial. In order to record the highlights of the Congress and to provide a summary for busy readers, Mr. Wilson has prepared this present report. It is, however, a personal report and not a consensus one.

Ottawa May 1980

C

.

B. Crawford Director, DBR/NRC

NATIONAL RESEARCH COUNCIL OF CANADA DIVISION OF BUILDING RESEARCH

DBR INTERNAL REPORT NO. 461

THE REHABILITATION OF BUILDINGS: REPORT ON THE SECOND CANADIAN BUILDING CONGRESS

TORONTO, 15-17 OCTOBER, 1979 by Andrew H. Wilson

Checked by: G

.

P

.

W. Approved by: C

.

B

.

C

.

Date: May 1980 Prepared for: Genera1 Distribution

Mayor Sewell of Toronto opened the Congress.

He said that his city is trying to keep as many old buildings as possible. Those already saved from demolition include Union Station. But the visual appeal of a building should not be the principal

criterion for its preservation. Some buildings should be saved, whether beautiful or not, because they are familiar landmarks. Others should be saved in order to conserve resources. The main problems in

building preservation are not technical but are financial or associated with the application of building codes.

C.B. Crawford of the National Research Council followed Mayor Sewell.

He said that the rehabilitation of buildings is carried out for a variety of reasons. Today, the demand for such buildings is growing quickly and bodies such as the Canadian Committee on

Building Research must respond accordingly. An important objective of the Congress, therefore, is to provide a forum for the kinds of interdisciplinary, technical, and non-technical communications needed in the rehabilitation process. The three key questions are why?, what?, and how?, and their answers have socio-economic, technical, aesthetic, and regulatory elements.

The First Session: Rehabilitation Overview

This session was designed to provide an overview of the rehabilitation process. Robbins Elliott of the Royal Architectural Institute of Canada was Chairman.

The Rakhra-Wilson paper on The Market for Rehabilitation was presented by A.H. Wilson (of DBR/NRC).

This paper first discussed concepts and definitions of terms such as rehabilitation, renovation, recycling, and repair. Using definitions suggested by James G. Ripley in Canadian Building

(April 1978), Mr. Wilson said that "rehabilitation" means the

complete upgrading of a built structure. It may include "rest~ration~~ when this involves restoring the original intent and design of the

building, "recycling" when an existing structure is adapted for a new purpose, and most "heritagef' activities. It may also include "renovation" if routine or minor maintenance and repair work are not included, and "retrofitting" if the buildingfs systems are brought up to higher standards of energy consumption efficiency, security, and fire protection. The term flrepair" should not be used because it covers too broad a range of activities, nor should the terms "modernizationI1and "redevelopment" because projects involving them may also include significant amounts of new building. These con- cepts apply to both residential and non-residential buildings.

The ultimate decision in a rehabilitation project is whether to rehabilitate the building or to demolish it. In some cases this decision is made easier by government fiat permitting or forbidding demolition in a given set of circumstances. In Canada, rehabilitation and demolition are normally local concerns and the criteria are often arbitrary.

The Rakhra-Wilson paper then discussed a number of economic, technical and social factors that can affect the market for re-

habilitated buildings. Included among these are different kinds of cost-benefit analyses, tax laws and government incentive programs, the population mix and age structure, personal mobility and income, inflation, interest rates, fuel costs, the costs of producing

suitable materials, the technical implications of codes and standards and the costs of applying them, heritage laws and regulations, and factors such as lifestyle and quality-of-life.

The Housing Requirements unit of the Canada Mortgage and Housing Corporation has put together the following information for 1974, based on the results of two surveys:

-

-

There were approximately 6.6 million residential housing units in Canada that year, of which 894,000 (or about

13.5 per cent) were considered to be in need of rehabilitation.

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Of the 4.1 million owner-occupied units, 465,000 (or 11.5 per cent) were considered to be in need of rehabilitation, as were 429,000 (or 17.2 per cent) of the 2.5 million rental units

.

-

The units in need of rehabilitation were highest in Newfoundland in percentage terms, and in Ontario and Quebec in absolute terms.

The housing stock in Canada in 1979 is approximately 7.5 million units, of which 4.5 million are less than 25 years old, and

2 million or so were built during the last 10 years.

There have been no surveys made in Canada that provide estimates of recent rehabilitation activities in the non-residential sector. One way of overcoming this deficiency is to base an estimate on experience in the United States. One U.S. survey put the 1976 expenditures for this sector at $10 billion. Using the usual 10:l ratio, the Canadian figure would be in the neighbourhood of $1 billion. Experience indicates that non-residential rehabilitation activities in the U.S. fluctuate significantly from year to year.

Estimating the market for rehabilitated buildings in Canada in 1988 is a difficult exercise and can be ?erformed in a variety of ways. The Rakhra-Wilson paper chose to take the following approach:

-

to assume that the residential housing stock will rise to 9.4 million units by 1988 and that 13.5 per cent of this stock will be in need of rehabilitation; this provides for a market of 1.3 million units;

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to assume that the average annual value. in 1978 dollars. for non-residential rehabiligation will be $1 billion through the decade to 1 9 8 K

The following are the summary conclusions of the paper:

-

the process of rehabilitating residential and non-

residential buildings in Canada is becoming more cornmon- place ;

-

details of how the process is' affecting the construction industry and the economy are sketchy, and improvements in data collection and analysis are required;

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thus far, the most fruitful sources of information on rehabilitation have been public ones;

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t h e market f o r r e h a b i l i t a t e d r e s i d e n t i a l and non- r e s i d e n t i a l b u i l d i n g s i n t h e n e x t t e n y e a r s i s l i k e l y t o be v e r y l a r g e i n d e e d .

During t h e remainder o f t h e Congress, no one o f f e r e d a l t e r n a t i v e market e s t i m a t e s , a l t h o u g h many o f t h e f a c t o r s i n - f l u e n c i n g p o t e n t i a l estimate were d i s c u s s e d .

The second p a p e r was g i v e n by J a c q u e s D a l i b a r d ( o f Heritage Canada). H i s s u b j e c t was The Management o f t h e B u i l t Environment.

D a l i b a r d s a i d t h a t t h e 17development i n d u s t r y " h a s reached a c r o s s r o a d s between t h e o l d e r a and t h e new one.

The o l d e r a , he s a i d , w a s o n e i n which t h e c i t y had t o be r e p l a c e d by a new c r e a t i o n . E x i s t i n g r e s o u r c e s , m a t e r i a l s , and a r c h i t e c t u r e were expendable. Renovation was n o t p a r t o f i t , b u t d e m o l i t i o n and r e b u i l d i n g were. The key word was 11progress7'.

Governments had t a k e n s t e p s t o s u p p o r t t h e o l d era t h r o u g h s u b s i d i e s , t a x laws, and o t h e r i n c e n t i v e s

-

and t h e p r i v a t e s e c t o r had s u p p o r t e d i t t o o , as had t h e academic community. There was, i n f a c t , a n e n t i r e "climatell which p r e s e n t e d a series of o b s t a c l e s t o t h e b u s i n e s s o f r e n o v a t i o n , many o f which

-

l i k e b u i l d i n g code r e q u i r e m e n t s and t a x laws

-

s t i l l e x i s t e d .

D a l i b a r d s a i d :

"Given t h e emphasis on new c o n s t r u c t i o n t h e b u i l d i n g i n - d u s t r y h a s t o t a l l y g e a r e d i t s e l f t o employing tradesmen t r a i n e d t o d e a l w i t h new b u i l d i n g materials and new c o n s t r u c t i o n methods. T h e r e f o r e v e r y few s k i l l e d c a r - p e n t e r s , masons o r p l a s t e r e r s can work e f f e c t i v e l y and s y m p a t h e t i c a l l y on o l d e r s t r u c t u r e s . Also, c o n t r a c t o r s n o t used t o e s t i m a t i n g and s u p e r v i s i n g r e n o v a t i o n p r o j e c t s are r e l u c t a n t t o g e t i n v o l v e d i n r e h a b i l i t a t i o n o r even s i m p l e m a i n t a i n a n c e work. Because t h e q u a l i t y o f t h e workmanship s u f f e r s and t h e c o s t i s o f t e n p r o h i b i t i v e , many owners have l e t t h e i r p r o p e r t y d e t e r i o r a t e I T .

The major problem w i t h t h e o l d approach

-

nowadays

-

i s t h e q u e s t i o n o f c o s t . The a g g r e g a t e expense f o r i n d i v i d u a l s and s o c i e t y , D a l i b a r d s a i d , is g e t t i n g o u t o f a l l p r o p o r t i o n . For example, t h e rate o f i n f l a t i o n w i t h i n t h e c o n s t r u c t i o n i n d u s t r y i s a p p r o x i m a t e l y

30 p e r c e n t h i g h e r t h a n t h e r a t e o f i n f l a t i o n i n t h e Consumer P r i c e Index. The r e t u r n on i n v e s t m e n t f o r t h e o l d p a t t e r n o f c o n s t r u c t i o n i s becoming e q u a l l y q u e s t i o n a b l e , and t h e r e are s t r o n g i n d i c a t i o n s t h a t Canada h a s o v e r b u i l t . The baby boom is o v e r . The c o s t s of s e r v i c i n g a r e r i s i n g r a p i d l y . I n r e s p o n s e t o t h i s s i t u a t i o n , r e a l estate c a p i t a l i s l e a v i n g Canada f o r t h e United S t a t e s .

In response to this situation, also, the re-use of existing structures and materials is not only becoming more competitive, it will soon be imperative. Although there will always be a demand for new construction, it will be lower in this new era than it was in the old one. And although there will be shortages of

certain skilled tradesmen, and the risk of dislocations within the construction industry, renovation appears to answer many of the needs which are currently being faced by the industry.

Renovation is labour-intensive, and therefore holds out excellent prospects for job creation. For local economics, it holds out possibilities for increased property values yet makes limited demands for additional municipal services. Already, governments have introduced incentives for rehabilitation and renovation, and this move has been endorsed

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for example

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by the Federation of Canadian Municipalities. Dalibard said that negotiations are currently under way between Heritage Canada and NRC to end the llbottlenecklf

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his phrase

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which building codes have caused to renovation projects. In universities across Canada, courses are now being planned for students and practicing professionals to train them in proper renovation techniques. Various entrepreneurs are acquiring "track recordsf1 which provide financial institutions with a basis for more enlightened mortgage loan policies. But, in

Dalibardls view, much remains to be done to further encourage building renovation in this country.

The third speaker was one of Canada's rehabilitation

entrepreneurs

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Jack Diamond (of A.J. Diamond Planners Ltd., Toronto). His subject was Rehabilitation in Practice. His oral presentation differed in some respects from his prepared paper. The account that follows endeavours to capture the main points from both.

First, Mr. Diamond's oral presentation.

Rehabilitation is no longer just a fad or fashion. It is an economic necessity, can be done profitably, and is a fundamentally sound and secure form of investment. However, it is usually difficult to know beforehand just how much a particular project is going to cost, but you don't have to do the whole thing at once. There should also be generous allowances for contingencies. In the longer run, it is the revenues-versus-costs that are important. Land values are only important in so far as densities are concerned.

When the function of a building is changed through re- habilitation or renovation, the questions of zoning, planning, and other approvals become important. There is more than one way to make such a building safe. Industrial buildings are best for use- change rehabilitations.

During the question period,

Mr.

Diamond was caught up in a fee structure discussion and in a discussion of the relative costs of new buildings and rehabilitated ones. With regard to the latter, he said that every project should be considered separately although, as a general rule, soft costs (legal fees, insurance, etc.) would amount to about 20 per cent of hard costs. He also emphasized the need

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in rehabilitation projects

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to take into

account the different potential life spans of the original structures, roofs, services, and other components of buildings.

Mr. Diamond's written paper enlarged on some of these points. He wrote, for example:

"For rehabilitation projects, the contingency factor which is added to the coristruction cost must be a major con- sideration. Rehabilitation costs can escalate more rapidly than with a conventional construction project because of the great number of uncertainties and unknowns in the building elements that the quantity surveyor cannot anticipate when making the original cost estimate. Rarely does the renovator have access to the original working drawings, if any were produced, and even more rare is the possibility of finding plans of alterations and additions made over the years

....

"When calculating potential annual revenues, it must be remembered that these can only be generated by the

rentable spaces in the building. Thus, while construction costs will be incurred throughout the building, the ratio of net leasable to gross building area is usually lower in old buildings. The amount of revenue-producing space is reduced by thick walls and columns, high ceilings, and sometimes odd configuration

....

"Heritage conservation policies in the community's Official Plan may also assist the renovator

....

Another advantage is the higher profile of renovation and the emotional appeal of heritage buildings

....

When a renovation project includes acquisition of the building, there are several sources of revenue for

financing the project. The building's current owner can often be persuaded as a condition of sale to take back the mortgage as a second mortgage, which opens an opportunity for institutional sources of funding

....

"Government assistance for private renovation projects is

"The U.S. Department of Commerce estimated in 1978 that one million dollars spent on rehabilitation created an average of 109 jobs while the same amount spent on demolition and new construction generated only 69

new jobs

....

"Strict application of the building codes currently in use across Canada have done much to lirnit the re- habilitation potential of many reusable structures.... Flexibility is necessary when interpreting the Code for rehabilitation purposesfr.

Mr.

Diamond presented a series of slides to illustrate some of the projects in which he has been i.nvolved.

The last speaker i n the First Session was Architect A. W.

Cluff (of A.W. Cluff and P.J. Cluff, Toronto), whose paper was an Evaluation of Buildings for Rehabilitation.

Cluff said that the rehabilitation of buildings and their restoration for continued or changed use requires the careful evaluation of a multitude of factors not usually considered when contemplating the construction of a new building. To be successful in a rehabilitation project, the architect must therefore identify the kinds of informa- tion required for this evaluation, decide how much of it to seek, apply criteria for usefulness and acceptability, and develop a methodology for putting the information to work.

The architect's solution to any rehabilitation problem is bounded by time and cost limits. He is not at liberty to try every possible solution to it, and must rely onhis training and previous experience. And he must also be prepared to explain the solutions he proposes.

The architect's evaluation of a rehabilitation project should include these steps: a statement of the objectives; an analysis of the user groups; its relationship to other facilities and, where applicable, to other organizations, governing bodies, etc.; the nature and range of the uses, together with any limiting

factors which may affect these; a list of spatial and environmental elements required to support these uses; and the required phasing sequence and time scale.

Cluff said that, in his firm's experience, insufficient time is frequently given to the study of the elements of this evaluation. There is a strong tendency to proceed too soon with design development. But starting drawing early may lead to lack of client confidence and eventually to litigation. There are also possible complications arising from the fact that d b1,ild~ng may be subject to statutory requirements not enforceable prior to its rehabilitation.

One of the most important factors in data collection is to collect the most critical facts first. For example, the existing building may be unable to meet current fire safety and health

codes. In the case of a building in which the continuation of its present use is contemplated, this use by floor, the

adjacencies, and the adequacy of assigned areas are most important. And, of course, its owner must be certain of its intended use

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whether or not any changes are contemplated.

The evaluation may be made under several general headings. Space: the study of the activity systems contemplated for the

building; the desired adjacencies; communications and inter-

relationships of the available space; and the translation of present space allocations into the new ones.

Environment: the conditions required to accommodate the new activity systems.

Building Systems: the study of the components of the building

under the headings of thestructure, service installations, and plant, equipment, furnishings, fittings and finishes.

Resources: the study of the cost aspects of the resources 'consumed' by the building.

The particular headings for the evaluation may be:

Basic information: building identification (location, age, owner- ship, etc.), and description (occupancy, zoning, size, location, floor areas, installations, services).

Physical evaluation: Site and landscaping, foundations, structure, exterior cladding, wall openings/doors/windows, roof, interior walls and finishes, ceilings, electrical installations, mechanical/

ventilating/heating/air conditioning equipment, plumbing, stairs and vertical transportation, and specialized spaces.

Functional evaluation: exterior, interior, special equipment areas, and maintenance and services.

One paragraph from Cluff's text should be especially noted: ''....to an increasing degree, the requirements of Building

and Fire Codes play an important role in the evaluation of all buildings for rehabilitation. The current practice followed in some areas of requiring the entire building

to be brought up to the present code requirements when alteration, renovation or rehabilitation takes place is considered one of the greatest deterrants to this process due to sometimes prohibitive costs and also the physical impossibility to do so. It is to be sincerely hoped that greater flexibility without, of course, increased risk to buildings or users, will be permitted in order to provide increased building rehabilitation opportunities which are financially and practically viablen.

With the process of evaluation completed, the designer is then free to follow the normal route of design development.

The Second Session: Evaluation and Rehabilitation Technology

Chairman

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David B. Leaney (D.W. Thompson Consultants Ltd.) The first paper in this session was by B.R. Morgan and

N. McAskill (of Hardy Associates (1978) Ltd., Vancouver), and was

presented by Dr. Morgan. It was on Materials Evaluation and Rehabilita- t ion.

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This paper described in some detail the rehabilitation of the old Carnegie Library in downtown Vancouver, which was built in 1904. But before doing this, Dr. Morgan described the principles of materials evaluation.

The first step in assessing the condition of an existing building is the detailed visual examination of all structural com- ponents and materials. Of particular interest are details of the structural framing, including the dimensions and spans of major load- bearing walls, pilasters, columns, and beams. Details of the

connections of load-bearing elements must be established. Such examinations will often require the extensive removal of panelling, stucco and other cladding, and the examination of through-the-wall and roof and floor details will require holes to be cut. The visual examination should also look for evidence of deterioration

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for example: moisture and freeze/thaw deterioration and cracking of masonry, the crumbling of mortars, dry and wet rot and fungi in

wood components, pitting and rusting of metal structural and fastening components, and water penetration of roofing materials.

Since most older buildings in Canada have exterior load- bearing walls or facades of brick or stone or both, their load carrying capacities should be established by testing. In seismic

r e g i o n s o f t h e c o u n t r y , tests o f t h e r e s i s t a n c e o f masonry w a l l s t o l a t e r a l l o a d i n g c o n d i t i o n s w i l l a l s o b e r e q u i r e d . Most o l d e r b u i l d i n g s were b u i l t a s g r a v i t y s t r u c t u r e s w i t h v e r y l i t t l e , i f a n y , t e n s i l e r e i n f o r c e m e n t i n t h e p l a n e of t h e w a l l . Such s t r u c t u r e s r e l y on t h e s h e a r s t r e n g t h developed between masonry u n i t s and m o r t a r f o r r e s i s t a n c e t o l a t e r a l l o a d i n g .

A d d i t i o n a l i n f o r m a t i o n on t h e q u a l i t y o f t i m b e r

s t r u c t u r e s can be o b t a i n e d by i n c r e m e n t a l b o r i n g . Timber members t h a t a p p e a r sound on t h e o u t s i d e may s u f f e r from i n t e r i o r d e t e r 2 i o - r a t i o n .

R e h a b i l i t a t i o n , Morgan s a i d , w i l l o f t e n r e q u i r e t h a t e x t e n s i v e s t r u c t u r a l m o d i f i c a t i o n s be c a r r i e d o u t t o a b u i l d i n g t o meet t h e p r o v i s i o n s o f t h e NBC o r l o c a l Codes. Changes i n occupancy w i l l be an i m p o r t a n t f a c t o r i n t h i s r e g a r d . And many o l d e r b u i l d i n g s were c o n s t r u c t e d when no seismic Codes e x i s t e d . I n some o f t h e s e s t r u c t u r e s , i t w i l l be u n u s u a l l y d i f f i c u l t and e x p e n s i v e t o b r i n g them up t o t h e Code r e q u i r e m e n t s u n l e s s l o c a l a u t h o r i t i e s are p r e p a r e d t o c o n s i d e r a p p e a l s f o r t h e r e l a x a t i o n o f t h e s e r e q u i r e m e n t s and where t h e s t r u c t u r e can be b r o u g h t up t o a s t a n d a r d a p p r o a c h i n g some a c c e p t a b l e p r o p o r t i o n o f t h e Code r e q u i r e m e n t s . To c a r r y o u t t h e s t r u c t u r a l r e h a b i l i t a t i o n o f t h e Carnegie L i b r a r y , e x t e n s i v e g u t t i n g o f t h e i n t e r i o r w a s n e c e s s a r y . S t r u c t u r a l a d d i t i o n s i n c l u d e d :

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s t r e n g t h e n i n g t h e e x i s t i n g walls by m e c h a n i c a l l y c o n n e c t i n g t h e e x i s t i n g b r i c k and n a t u r a l s t o n e masonry t o a r e i n f o r c e d s h o t c r e t e w a l l t h a t extended down t o t h e f o u n d a t i o n s ;

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s t r e n g t h e n i n g t h e e x i s t i n g masonry p i l a s t e r s u s i n g r e i n - f o r c e d s h o t c r e t e c o n s t r u c t i o n ;

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r e i n f o r c i n g t h e wood frame f l o o r s w i t h s t r u c t u r a l s t e e l beams and r e i n f o r c e d c o n c r e t e t o p p i n g ;

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i n s t a l l i n g a s p e c i a l s t e e l frame t o p r o v i d e s t r u c t u r a l s u p p o r t f o r t h e b u i l d i n g ' s r o t u n d a . With r e g a r d t o t h e r e h a b i l i t a t i o n o f t h e e x t e r i o r s t o n e masonry o f t h e l i b r a r y , Morgan and McAskill w r o t e i n t h e i r p a p e r :

"The exterior surface was restored to an aesthetically pleasing condition by chipping and hammering to remove slabbing and sealing surfaces and then sand blasting the entire exterior surface. This technique proved to be quite successful for rough hewn sandstone blocks, but it is not recommended for smooth dressed blocks as these can become excessively eroded. ...I1

"The exterior sandstone masonry was finally coated with a water-repelling compound

...."

(The technique of sandblasting exterior masonry was a subject of discussion throughout the Congress. Dr. Morgan said, for example, that in his experience sandblasting has limits as a method for cleaning badly stained outside surfaces. On smooth cut blocks, wet sand blasting is not very satisfactory. Light water

pressure blasting does not remove stains effectively. Chemical washes are not very successful. There appear to be no specific answers that can be universally applied. Experimentation is required.)

The second paper was presented by Per T. Christoffersen (of Read Jones Christoffersen Ltd. of Vancouver) on Evaluation and Rehabilitation of Existing Building Structures and their Components.

Right at the beginning, Christoffersen stressed the im- portance, on a rehabilitation project, of a happy client/engineer relationship. The engineer should, after an initial investigation of the project, express an opinion to his client on the probable structural implications, on whether the project is realistic, on his involvement in it, and on the adequacy of the budget.

Following A.W. Cluff, Christoffersen said that the first step in an evaluation is to determine what information is required, and how it should be obtained. Following D.R. Morgan, he said that the* engineer must acquire a clear picture of the structural systems and components in the existing building. These should be evaluated on the basis of judgement based on past experience, by engineering computations based on known dimensions and material properties, and by load tests. The following structural components require in- vestigation

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those that:

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show signs of distress or deterioration;

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will be directly affected by the renovation;

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will receive increased loading;

If no drawings exist, they must be produced by measure- ments made on-site.

With regard to on-site investigations, Christoffersen said :

"Reinforced concrete can be the most expensive material to investigate because of the difficulty in obtaining detailed information on the reinforcement. Bar sizes, number and spacing, locations, type of deformations, lengths, end anchorage and grade of steel can only be determined in a few locations because of costs.

Removal of concrete to expose the bars is the most

frequent method used, although more sophisticated methods are available. Coring for concrete strength tests is standard practice and usually no problem1'.

Foundations are seldom investigated on-site unless there are indications of excessive settlements, because of the costs involved.

Christoffersen said that, provided sufficient in-

formation has been obtained from drawings and on-site tests, structural analyses for gravity loads should be straightforward. Where this in- formation is lacking, the application of judgement regarding the

quality of the original design and construction and of experience from other buildings of the same type should be applied. Most old

buildings have been well tested by wind loading, and unless they have had problems in the past, should not have any in the future unless the structure is weakened by deterioration or the removal of bracing elements. However, Canadian buildings more than 25 years old were not designed or constructed to resist the inertia forces generated by earthquake motions. To strengthen them to resist these

forces is usually the most difficult and challenging part of re- habilitating building structures in Seismic Zone

3.

(Usually, not all earthquake requirements can be met and negotiations with the Building Authority will be necessary.)

The remainder of Christoffersenls paper dealt with the techniques for strengthening buildings for gravity and earthquake loads. As did all speakers from Vancouver, he had a special concern for earthquakes. In summary, he said:

Y'here are almost an infinite number of problems and solutions and accurate cost information can only be compiled for special cases. The structural upgrading of a brick and heavy timber buildi ng.... will cost more

fifty per cent of that is for earthquake upgrading (where this is applicable)

....

Perhaps government

grants or tax incentives should be offered to owners of heritage buildings to allow more comprehensive earth- quake strengthening to be carried out.l1

The third paper in this Second Session was given by G.K. Garden (of G.K. Garden Building Science Consulting Ltd., Calgary). It was on the Evaluation of the Existing Building En-

velope.

The evaluation of an existing building is required primarily for the determination of the economic feasibility of re- habilitation. It is also required to determine if, and how, the building envelope can be modified to ensure acceptable performance and durability. Ultimately, it must accurately predict the potential performance of a new construction, made up in part of the existing construction with new environmental conditions inside it. Also, according to Garden, a building science analysis for evaluation of an existing construction is identical to that which should be

performed for any proposed new construction, with one major compli- cation

-

the existing building. Information acquired for this analysis is generally available

-

particularly in the form of the DBR/NRC Canadian Building Digests.

Such investigations differ from the procedural point of view from one investigator to another and from one building to another. Because of these factors, Garden said he does not believe it is possible to establish a universal "methodology for building investigation".

Experience is an essential part of the investigator's equip- ment. A keen eye and thoroughness in his work are others. Picture-

taking is an essential technique for him to master. The availability of enough information for a building science analysis to be made during the preliminary investigation is a definite advantage, as is first-hand information on the past performance of the building in question, but drawings can be out of date, and people's recollections can be inaccurate, so care should be taken when interpreting them.

After the preliminary investigation, a detailed list of items for what Garden called "explorat,ory surgery" can be prepared. This surgery is necessary to confirm construction details and to determine the state or condition of concealed materials, and it may also be required to determine the cause of inadequate performance or

lack of durability. From experience, Garden has found that "a .conservative, thrifty attitude causing a reluctance to do damage

to the building fabric or to spend much money on this work can be a serious handicap". On the other hand, it makes no sense to do unnecessary damage.

It is often necessary to have samples of the materials removed during surgery subjected to laboratory examination. But there are also in-situ destructive and non-destructive test pro- cedures that can be used.

The normal performance inadequacies in a building are rain penetration, condensation, and excessive heat loss or gain, and there is normally a common factor in all of these

-

air leakage. In his paper, Garden gave a lengthy description of the detection and implications of air leakage. He suggested the use of thermography in studies of the thermal condition of a building. He also suggested that it could take up to a year to complete a building inspection since its performance in all weathers should be monitored.

When all the detailed investigations and surgery have been completed and the materials testing reports received, an evaluation by building science analysis can be performed.

Significantly, the majority of the slides sk~own during Garden's presentation were of

-

new buildings in need of' repair

-

for reasons including inadequate design

-

rather than of old buildings in need of rehabilitation. Therefore, the kinds

of

inspections described by Garden may be applied to

-

all buildings regardless of their age. However, as Professor Baker (Universitk Laval) pointed out during the discussion period at the end of the Second Session, a distinction should be made between the old/rehabilitation and new/repair categories.

The fourth paper was presented by Max C. Baker (of NRC/DBR) on Rehabilitation of the Building Enclosure.

Baker noted in his paper that the basic function of walls, windows, roofs, and floors

-

referred to collectively as the

"building enclosure"

-

is to protect the interior from the un-

controllable exterior weather conditions in such a way that the interior conditions can be controlled and adjusted to provide an environment suited to the activities of the occupants or to ensure that the building contents remain in the. condition desired. (Histori- cally speaking, effective interior control has not always been

B a k e r ' s c o n c l u d i n g summary p a r a g r a p h was as f o l l o w s : l l R e h a b i l i t a t i o n of b u i l d i n g s u s u a l l y r e q u i r e s new i n -

t e r i o r e n v i r o n m e n t a l c o n d i t i o n s t h a t w i l l n o r m a l l y i m - p o s e a more s e v e r e environment on t h e b u i l d i n g e n v e l o p e t h a n e x i s t e d i n t h e o r i g i n a l b u i l d i n g . The walls and r o o f must be d e s i g n e d t o m a i n t a i n t h e d e s i r e d d e g r e e o f s e p a r a t i o n of t h e two d i s s i m i l a r e n v i r o n m e n t s , and t h i s w i l l u s u a l l y i n c l u d e t h e r m a l u p g r a d i n g . The main f a c t o r s t o be c o n s i d e r e d , i f d e t e r i o r a t i o n o f t h e r e h a b i l i t a t e d e n c l o s u r e is t o be a v o i d e d , are a i r l e a k a g e and r a i n p e n e t r a t i o n c o n t r o l " .

Most o f t h i s p a p e r was concerned w i t h d e t a i l s o f wall and r o o f c o n s t r u c t i o n t o a c h i e v e t h e s e a i r l e a k a g e / r a i n p e n e t r a t i o n o b j e c t i v e s . The f o l l o w i n g comments were made e a r l i e r i n t h e p a p e r and refer i n a g e n e r a l way t o r e h a b i l i t a t i o n problems and t h e b u i l d i n g e n c l o s u r e :

-

For t h e most p a r t , t h e e a r l y immigrants t o Canada b r o u g h t w i t h them t h e b u i l d i n g s y s t e m s and s t y l e s used i n t h e i r

former homelands. Not much a t t e n t i o n was p a i d , i n i t i a l l y , t o t h e d i f f e r e n t climatic c o n d i t i o n s i n Canada, and problems o f b u i l d i n g performance r e s u l t e d . But o v e r t h e y e a r s ,

a r c h i t e c t s and b u i l d e r s l e a r n e d how t o a c h i e v e a r e a s o n a b l e environment i n t h e i r b u i l d i n g s and how t o a v o i d d i f f i c u l t problems o f w e a t h e r i n g and v i s u a l d e t e r i o r a t i o n .

-

B u i l d i n g s of masonry c o n s t r u c t i o n b u i l t f o r permanency i n urban areas are t h e o n e s t h a t have s u r v i v e d and are

f r e q u e n t l y i n v o l v e d i n r e h a b i l i t a t i o n p r o j e c t s t o d a y . Masonry walls u s u a l l y performed w e l l b e c a u s e o f t h e i r t h i c k n e s s .

-

I n many r e h a b i l i t a t i o n p r o j e c t s c a r r i e d o u t nowadays on t h e b a s i s o f economic v i a b i l i t y , i t i s g e n e r a l p r a c t i c e t o clear

o u t t h e e n t i r e i n t e r i o r o f t h e b u i l d i n g s , l e a v i n g o n l y t h e s t r u c t u r e and some o r a l l o f t h e e x t e r i o r w a l l s and r o o f s . The e x t e r i o r a p p e a r a n c e o f t h e f a c a d e , o r some r e s t o r a t i o n t o t h e o r i g i n a l a p p e a r a n c e , i s u s u a l l y what is d e s i r e d and is r e t a i n e d . The i n t e r i o r c o n d i t i o n s are t h e n b r o u g h t up t o p r e s e n t - d a y s t a n d a r d s i n r e l a t i o n t o u s a g e , e n v i r o n - m e n t a l c o n d i t i o n s , s e r v i c e s and a p p e a r a n c e .

-

It is unlikely that much thought was given, during

(the original) design and construction, to the environment modification function of the walls of older buildings now being rehabilitated.

-

Any changes to the interior conditions or to the enclosure of rehabilitated buildings will usually subject the en- closure to new temperature and moisture conditions. This requires that the (modern) principles of enclosure design be applied. Otherwise, problems may occur that cause rapid deterioration of the rehabilitated enclosure.

-

Although masonry buildings in earlier times gave good per- formance, some of those built in the past fifty years have not fared so well. This is due mainly to changes in

materials and construction practices, the effects of which were not recognized by designers and builders. The intro- duction of building frames, for instance, was a great structural improvement and paved the way for the use of larger individual wall units of masonry or concrete that could be hung on the frames. But the larger units increased the thermal and moisture movements which produced larger cracks at fewer joints, often extending through the thinner walls to allow rain penetration inside.

-

The demand for more desirable occupancy conditions inside buildings brought about the increased use of central heating, ventilating and air conditioning. Insulation to control heat loss or gain became a necessity to measure the

efficiency and reduce the cost of providing such services.

-

Failure to consider functional requirements in the re-

habilitation of buildings will almost certainly lead to unsatisfactory technical performance. It has already occurred in many recently constructed buildings.

The fifth speaker was R.T. Tamblyn (who is President of Engineering Interface Ltd. of Toronto) and his subject was HVAC Retrofit for Commercial Buildings. He began with this statement:

"Designers concede a 20 year life for mechanical equip- ment. But piping and radiators installed in 1895 in the old Toronto City Hall still heat the building. Rivetted ducts, alongside the steam pipes, have seen less use, but are as structurally sound as the day they were installed.

A 1 9 1 1 A.D. S h e l d o n s v e n t i l a t i n g f a n i n t h e f o r m e r T-D Bank h e a d q u a r t e r s b u i l d i n g was s p e e d e d up i n 1 9 5 1 t o accommodate t h e r e s i s t a n c e o f a c o o l i n g c o i l f o r t h e a i r c o n d i t i o n i n g r e n o v a t i o n . A l r e a d y 40 y e a r s o l d , u s i n g t h e o r i g i n a l b e a r i n g s , i t s e r v e d a f u r t h e r 1 0 y e a r s , w i t h a larger m o t o r , b e f o r e t h e b u i l d i n g g a v e way t o t h e T-D C e n t r e . No wonder o p i n i o n i s d i v i d e d on t h e l i f e o f HVAC p l a n t u .

Tamblyn went o n t o s a y t h a t , w h i l e equipment may wear t o t h e e x t e n t i t i s c h e a p e r t o r e p l a c e t h a n r e p a i r , many s y s t e m s undergo r e n o v a t i o n b e c a u s e o f t e c h n i c a l c h a n g e . F o r example, s i n c e 1 9 5 0 , v a r i o u s v e n t i l a t i o n s y s t e m s have been upgraded t o c o m f o r t c o o l i n g . I n t h e same p e r i o d , steam h e a t i n g s y s t e m s have been c o n v e r t e d t o h o t water. Steam h e a t l o s t p o p u l a r i t y when Codes began t o demand r e g i s t e r e d o p e r a t o r s and l o s s o f s t e a m vacuum downgraded t e m p e r a t u r e c o n t r o l .

But t h e new i m p e r a t i v e o f t e c h n i c a l change i s t h e c o n s e r v a - t i o n o f e n e r g y . A w h o l e s a l e r e n o v a t i o n o f HVAC i n b u i l d i n g s is under- way. P a r a d o x i c a l l y , i t i s t h e more r e c e n t d e s i g n s which are t h e g r e a t e s t e n e r g y c o n s u m e r s , and may b e t h e f i r s t t o g o . A l s o , some b u i l d i n g s

have undergone more t h a n o n e r e n o v a t i o n , t h e most r e c e n t b e i n g t r i g g e r e d by t h e need f o r e n e r g y c o n s e r v a t i o n .

The examples c i t e d i n t h e Tamblyn p a p e r were p r i n c i p a l l y f o r t h e commercial b u i l d i n g s e c t o r . Most o f t h e c o n s e r v a t i o n work t h u s f a r h a s been done on t h e b a s i s o f e n g i n e e r i n g a n a l y s i s and m i n o r hardware c o s t s .

Under t h e h e a d i n g o f "Choosing t h e R i g h t Energy Source1', Tamblyn s a i d : "One o f t h e f i r s t i m p e r a t i v e s i n a m a j o r r e t r o f i t i s a n e x a m i n a t i o n o f e n e r g y c h o i c e s f o r h e a t i n g and c o o l i n g . T h i s r e q u i r e s e i t h e r a c r y s t a l b a l l o r t h e s e l e c t i o n o f s y s t e m s f o r which t h e f u e l c a n b e e c o n o m i c a l l y s w i t c h e d l a t e r o n .

v H i s t o r i c a l l y , t h e r e have been t h r e e main c h o i c e s

-

o i l , gas and e l e c t r i c i t y . Along w i t h t h e s e are t h r e e e l e c t r i c m o d i f i c a t i o n s which r e q u i r e s p e c i a l a t t e n t i o n . They are e l e c t r i c r e c l a i m o f waste h e a t , e l e c t r i c i t y u s e d " o f f peak", and waste h e a t r e c l a i m and c o o l i n g u s e d

_-

" o f f peak". The two l a t t e r r e q u i r e some form o f t h e r m a l s t o r a g e " .

Other energy-consuming imperatives that must be examined include lighting, air circulation, and pumping.

The remainder of this paper discusses details of the various energy-saving HVAC systems, ending with a table showing savings achieved between 1975 and 1979 in commercial space. These savings ranged from 37 to 70 per cent.

The final paper in the Second Session was by A.W. Levy (of NRC/DBR) and E.R. Thorn (of Eric Thorn Associates Ltd., Vancouver) on Evaluation and Rehabilitation of Building Lighting Systems. Dr. Levy presented it.

He said there are two good reasons for paying close attention to installed lighting systems in rehabilitation projects. These

systems are almost certainly large energy consumers, and may account for up to 50 per cent of total energy consumption, including the cooling load placed on air conditioning systems in summer. And old lighting systems may be entirely unsuitable for the visual needs of the new occupants, and could affect their productivity which, in turn, could affect the lease/resale potentials of the

buildings.

Levy said that the financial consequences of poor lighting systems are significant and, traditionally, owners, developers, and architects have not employed lighting specialists, preferring to leave lighting to the electrical consultant. Low first costs for these systems have been the prime consideration. Lighting specialists are, of course, concerned with the building envelope, fenestration, & landscaping as well as lighting systems. For example, decisions concerning solar heating can almost certainly affect daylighting for interior illumination.

Levy said that, to evaluate an existing lighting system and then plan a rehabilitation program, there must be clear criteria and/or proper standards.

Illuminance levels are the most meaningful and im- portant design parameters and their magnitude influences the performance of tasks, energy consumption and space utilization, but in a non-linear fashion. Doubling the light does not necessa- rily double productivity, nor will twice the electrical energy be consumed. Criteria for assessing these levels exist already. But, in addition to illuminance, the geometry, polarization, and spectral composition of the incident illumination will also need

consideration for specific tasks. Again, criteria for assess- ment are available. At the same time, it should be appreciated that light entering the eye directly from fixtures, windows, walls, and so on, can affect visibility and visual comfort.

Energy efficiency criteria are available, as are model lighting energy budgets.

Then Dr. Levy said:

"Costs of lighting rehabilitation, including consultants fees, remain an overriding criteria. Gn either a first cost or life cycle cost basis, the rehabilitated lighting system must be an attractive economic investment. If first cost appears to be high, a life cycle cost analysis should be performed. The productivity benefits and

increased resale value afforded by a quality lighting system should be considered."

The paper discusses lighting installation evaluation methodologies, including codes & standards, and then describes new design concepts which, it says, are inextricably linked with new technology. Some concepts are new engineering expressions of old and tested rules of thumb, while others are revolutionary.

With regard to rehabilitation methods and new lighting technology, the paper says that the last five years have seen a plethora of new hardware, lamps, ballasts, and controls speci- fically produced for the retrofitting of lighting systems and for new installations to enable energy reductions through improved efficiency. The paper then says:

"Rehabilitation must be planned carefully. Panic and ad hoc measures are generally counterproductivein terms of money, time and benefit. Renovations are more likely to be successful if the present lighting situation is well documented in terms of light level, nature of visual

tasks, workers' ages, wiring and switching layouts, type and age of lamp fixtures, condition of painted and reflecting surfaces, and operating and maintenance patterns. It is also important to allow for those

individuals who require special lighting for opthalmological reasons.

"

The paper says that it seems practical to divide re-

habilitation methods into three categories on the basis of financial investment:

-

where no capital investment is required, and only regular staff labour costs are incurred;

-

when contract labour is required, the short pay- back method (less than three years) would be used; and

-

the long pay-back period (more than three years). The Third Session: Rehabilitation and Building Codes

Chairman: Peter Dobbing (Architect )

In his introduction, Peter Dobbing said that Codes are becoming more stringent by the year. The 50-year-old building has become very obsolete. But there are two ways to write codes; to have them responsive to all possible circumstances; or to have them meet the "lowest common denominatorf'. The first way is very complex, the second much simpler. Most codes follow the second. Similarly, there are two methods of inspection: to go by the book; or to go by the spirit of the code. Again, the latter is the better way.

The first speaker was R.L. Maki (of the Department of Permits and Licences, City of Vancouver) whose subject was Rehabilitation Guidelines for Building Officials. He began by saying :

"We, in the City of Vancouver, have been most fortunate in that our Building Board of Appeal has proven to be an excellent soundingboard for evaluating practical solutions, ever since its founding in 1975. This has proven to be a major factor in the development of "Alternative Requirements for Existing Buildings" as they appear in the current Vancouver Building By-law. "In addition, our City Council requested that we form

an informal committee, with other major cities from the Western Provinces, in order to go further yet in our study of practical requirements and guidelines for the rehabilitation of existing buildings."

In the old days, municipal authorities were concerned more with the external appearance of a building, its structural stability, and the additional tax revenue it could generate. For these purposes, Building By-laws were simple. But tragedies, judicial decisions on negligence, and technical advances

-

among other things

-

caused a gradual evolution of very comprehensive building control standards. Obviously, in the circumstances, existing buildings became increasingly non-conforming as new standards were developed and adopted.

Yet, Maki said, there is no single document which explains the intent of the requirements of the NBC in Canada. This poses a challenge to Building Officials and designers "when it comes to logical rehabilitation standards for existing buildings, especially when additions, extensive alterations, or change of use are con- templated by building owners1'.

Vancouver is experimenting. Whenever extensive work is being done on an existing building, a structural analysis must always be carried out to determine the safe, extended use of the building, and especially where the original intended protection from the weather has deteriorated and exposed the structure to environmental or groundwater damage. Fortunately, most existing buildings have been over-designed because of past standards and are found suitable for today's gravity loads. But they are not necessarily suitable to withstand the earthquakes or other

natural forces which have caused a major upgrading of structural standards in some regions of the country. Consequently, con- trolled relaxations from the full seismic requirements have been allowed only when certain criteria are met.

Occupancy has to be carefully monitored. Fire risks, and the risk of smoke in higher rise buildings, also require that special steps be taken. For example, in residential occupancy buildings of combustible construction which are higher than three storeys, sprinkler protection can be relied upon to permit more effective use of the building so long as strategic early warning systems are installed to waken sleeping occupants as early as possible and connections are provided to central fire stations.

Maki discussed several other examples to which alternative arrangements to new code provisions have been developed. In con- cluding, he said:

"Design professionals cannot prepare realistic feasibility studies without introducing the seemingly inconsistent discretion of a Building Official operating without proper tools.

"Without officially-recognized compensating guidelines, preliminary reviews of rehabilitation proposals just cannot be quickly concluded by Building Officials without the constant fear of over-looking unforeseen basic safety requirements.

"Steps must be taken soon to introduce a new National Building Code companion document, Guidelines for the Rehabilitation of Ekisting Buildings!"

J.K. Richardson (of Rolf Jensen and Associates Ltd., Don Mills, Gntario) spoke next, presenting the paper on A Systematic Approach to Fire Safety in Rehabilitation of Buildings which he co-authored with Rolf Jensen.

He said that fire protection plays a significant role in the rehabilitation process whether or not the reason for doing it is economic viability or historic significance. From the fire

protection point of view, rehabilitation (usually) results in a charge of occupancy or use or of the occupant load

-

for example, when storage buildings become offices, or schools become residences. The Toronto Young People's Theatre was once a stable, then a

transformer building.

Typical examples of the kinds of deficiencies old buildings have in the light of present day codes include: unprotected vertical openings; deficient means of egress; deficient structural fire

protection; deficiencies in the flammability of interior finishes; and a whole list of add-ons.

Richardson said:

"Model building codes typically present one method of

achieving compliance

-

upgrade to the present levels as far as possible. However, when a model building code is

applied to a rehabilitation project, there is usually a conflict with the owner's economic and preservation goals

....

rigid compliance in fact means tear down and start over."

Richardson said that an alternative method of achieving safety for rehabilitated buildings is the development of a program based on fire safety principles and which answers the question: How much fire safety is needed? In his view, the designer should not establish the criteria when human lives are being dealt with. The

minimum level of fire safety must be established by society, in consideration of the needs of the public at large. This is already done by Code Committees, acting as society's representa- tives.

Once the established level of safety for the fire protection program has been established, the fire safety problem must be identified and handled. The remainder of the Richardson/ Jensen paper dealt with the identification of this problem and the development of intervention measures to limit fire size or to stop fire and smoke spread, and gave an example of both problem identification and its solution. Its conclusion was as follows :

"Model building codes developed since 1960 are de-

signed to respond to contemporary construction techniques. They do not consider many outdated techniques which are found in existing buildings. Rehabilitation by its very nature usually involves a mix of the contemporary and former construction techniques.

"The solution then to rehabilitation fire protection is to apply an engineered systematic protection approach to the rehabilitation problems while still keeping in mind the increased sensitivity of rehabilitation projects to economic and architectural constraints,"

The remaining two papers in Session Three were by American authors and relevant to American experience. The first of them wasonTechnica1 Evaluation Needs for Building Rehabilitation by J.H. Piekert and J.G. Gross (of NBS/CBT, Washington) and was given by Mr. Piekert.

He began by saying that, throughout the U.S., there is increasing concern for the need to utilize the existing building stock more fully, a concern motivated by resource shortages and by the increasing cost of most materials and products used in new buildings. A Census Bureau estimate puts the annual loss from the country's housing stock at 200,000 units. He then said:

"While it is difficult to estimate the current number of building units being rehabilitated, 1978 expenditures for both residential and non-residential rehabilitation are estimated at

$53.3

billion. There are many forces

at work which potentially impede the efficient utiliza- tion of existing buildings. Market forces, financial considerations, government policy, industry structure and regulatory activities are but a fewft.

Piekert broke down the $53.3 billion figure into $38.3 billion for residential units and 15.0 billion for non-residential ones.

Piekert and colleagues at NBS/CBT have studied the

technical needs of regulatory organizations involved with building rehabilitation, including three model building code organizations and selected State and major city agencies. The important

technical issues emerging from this work are as follows:

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Most codes contain administrative provisions

stating that a building's conformance with the re- quirements of the code for new construction should in- crease in relation to the dollar amount of rehabilitation planned (more below).

-

The regulatory process has been identified as impeding the full utilization of existing buildings.

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The technical base of some current provisions of the building codes which have a strong impact on the re- habilitation of existing buildings has been questioned.

-

In many cases, those involved with rehabilitation have

limited information upon which to base responsive and cost-effective decisions.

-

The building codes for new construction, with its

generally prescriptive format, is the existing regulatory base for rehabilitation, but these codes present diffi- culties.

-

There is a lack of information on technical matters re- quired to make decisions in assessing the "conditiontt of an existing building and in selecting appropriate

materials, systems and application techniques for carrying out rehabilitation activities.

An example of the administrative provisions referred to above is the "25-50 per cent rule", which is based on the

following "economic hierarchy":

-

The alteration must be restored to at least its original condition for a renovation which costs

less than 25 per cent of the value of the building; or

-

the alteration must comply with the building code for

new structures when the cost is between 25-50 per cent of the building's value; or

-

the entire building must comply with the building code for new construction when alterations exceed 50 per cent of the building's value.

.The definition of "value" is not standardized and has been interpreted as either assessed value, market value, or replace- ment cost.

Piekert said that the State of Massachusetts recognized that its statewide code, which contains the 25-50 per cent rule, was inhibiting rehabilitation. A pilot project was therefore initiated to develop interim code provisions for existing buildings in the State, with technical support from NBS/CBT. Draft Article 22 of the ~ssachusetts State Building Code was subsequently developed. This Article incorporates a code concept to replace the 25-50 per

cent rule and allows the rehabilitation of existing buildings with- out necessarily meeting all new construction code requirements provided alternative compliance conditions are met. The code concept includes the following provisions:

-

all high hazard conditions must be corrected;

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the building must be occupiable;

-

the existing building becomes the minimum performance requirement;

-

the performance level of the building after rehabilitation must not be below that existing before the change;

-

additions would be required to meet code requirements for new construction or equivalent;

-

compliance with the building code for new construction or its equivalent may be required when the change in use is to a more hazardous occupancy or use group. A Building Rehabilitation Technology Group has been

established within NBS/CBT in recognition of the importance of con- serving the building stock in the United States. Its work pro- gram includes the following elements:

-

development of the technical bases for regulation and performance criteria;

-

development of condition assessment technology; and

-

development of responsive and cost-effective decision models.

Aspects of this program, in practice, include the pre- paration of technical evaluation manuals, investigation of the technical bases of building regulations, and the identification of research needs. The remainder of the Piekert/Gross paper is

devoted to a discussion of these. For the purposes of this present paper comments will be restricted to the identification of research needs.

Piekert said that the identification of technical issues and their organization by priority is now underway at NBS and at the National Institute of Building Sciences. Currently, NIBS is developing rehabilitation guidelines under contract to HUD.

The research categories identified by CBT include:

-

test methods for evaluation(e.g. condition assessment of plumbing and electrical systems ) ;

-

analytical procedures (e.g. method for estimating hydraulic and pneumatic loads on existing plumbing systems);

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field inspection guidelines;

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data on archaic systems (e.g. load capacity of existing structural elements) ;

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applications of innovative materials and systems;

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prediction of properties of materials in existing

buildings; and

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economic considerations (e.g. difficulties in estimating rehabilitation costs).

The second U.S. paper was by Charles J. Dinezio, the Qecutive Director of the Massachusetts State Building Code commission and was on the Massachusetts Rehabilitation Project (MRP) , to which James Piekert had referred earlier.

The weaknesses of building codes in regard to rehabilitation have been identified as follows:

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codes apply to new construction;

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requirements for complete code compliance are arbitrary and may tend to increase costs;

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the nature of current codes limits alternate solutions;

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regulatory organization and procedures tend to be

constraints;

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legal actions deter approval of alternate solutions; and

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the backgrounds and skills of code enforcement personnel are diverse.

Dinezio said that the desired approach to the problem of codes and rehabilitation

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as identified by the study for NBS

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should be to develop a revised system of treating existing buildings that ensures the intent of the codes is met for maximum protection of health and safety, while allowing flexibility in enforcement and a sound technical basis for alternate solutions to meet safety standards.

The MRP began in March 1978 with a meeting of the eight participating parties, called by the Governor of the State. They allpledged financial support. The scope of the project called for the prime contractor

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the National Conference of States on Building Codes

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to produce with the other members of the team an interim code document containing provisions for alterations and additions to existing buildup. These provisions were to establish a system for the design professional, the building owner, and State and

local enforcement officials to evaluate proposed code changes to an existing building. These provisions have been included as elements in a major revision to the Massachusetts State Building Code and provide officials with guidelines for working with the document, major technical issues which must be considered, and alternate technical solutions and approaches which are applicable in the State. An Advisory Council to the Code Commission was also formed. The final draft of the interim code was completed by August 1978 and sent for comment to the Commission. The comments were subsequently incorporated into the code. In late September

1978, three one-day workshops were held for local and State building officials to explain the interim code provisions, and to receive feedback. The major concerns of the officials were incorporated, and the revised document approved by the Commission, as Article 22 of the State Building Code. It became effective in June 1979. Dinezio said:

"One of the advantages we have in Massachusetts is the fact that we have a mandatory statewide building code applicable to all buildings and structures, which local municipalities cannot modify.

Article 22 is based on the philosophy that anything can be done to an existing building that increases, or does not reduce, the performance of the building as it exists, with the provision that certain minimum standards must be met with regard to the structural adequacy and number and capacity of exits. Article 22 discards completely any reliance on the value of the building or the work to be done on it. Instead, the requirements are based on ranking the various occupancy classifications in view of increasing hazard.

Because Article 22 has been in effect for so short a time, no case material is available. Nevertheless, a panel of officials was asked to analyse a set of six rehabilitation situations. Their responses indicated that, in no case, was it necessary to impose new-construction requirements on the buildings under Article 22. The preliminary general conclusions of this experiment were as follows :

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Article 22 will certainly allow individual building officials much more leeway in requiring full-code compliance and accepting alternatives.

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Interpretationswill not be consistent among the communities involved. They will reflect the building official's

interpretations regarding degree of code compliance and specific requirements.

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Building officials will exercise their prerogative under Article 22 and generally accept lesser require- ments than under the 50 per cent rule.

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Responsibility of the building official will be greater under Article 22, but no more than when the cost of re- habilitation fell between 25 and 50 per cent under the old rule.

Dinezio wrote in his paper that, other than Article 22,

there are three general ways in which jurisdictions can handle the problem of rehabilitation and the degree to which new construction code requirements must be met. These are:

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the so-called 25-50 per cent rule;

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prescriptive definitions of several levels of code compliance;

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a system of allowing variances to new code requirements without going through a formal appeals process.

The remainder of Dinezio's paper was devoted to detailed discussions of these three approaches.

Two further comments from his oral presentation should be noted. The first is that, the more professional the building

inspectors, the easier it will be to get rehabilitation into building codes. Second, in Massachusetts,building officials are being held liable for the consequences of their approvals and, in disputes, may be sued.

The remainder of Session Three was devoted to a panel discussion, chaired by Peter Dobbing and including the four speakers as panelists along with A.G. Wilson, Chairman NRC Associate Committee on the National Building Code. This dis- cussion covered the following points, among others:

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the decision-making process for building officials in rehabilitation situations;

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the application of codes to buildings, such as hospitals, with special occupancy requirements;