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Energy codes - international comparisons
Energy codes – international comparisons
Thomas, R.
NRCC-46728
A version of this document is published in / Une version de ce document se trouve dans : Building for a Global Future: Australia’s Built Environment, Surfers Paradise, Australia,
Sept. 15-17, 2003, pp. 1-15
ENERGY CODES - INTERNATIONAL COMPARISONS
Dr Russ Thomas
National Research Council of Canada
Abstract
The paper presents the background to the introduction of energy-related
regulation in the construction industry over the last 50 years. This is followed by a more in-depth comparison of the differing approaches that have been taken in the energy conservation area by some of the leading countries outside of
Australia. The regulatory frameworks in which these codes have been developed and incorporated are also discussed along with observations on the level of adoption that has been achieved.
Keywords
Regulatory Framework; Energy Codes; Energy Conservation; Building Envelope.
INTRODUCTION
This paper begins by placing the issue into its broader context not only geographically but also historically and in terms of its scope. Although there
were occasional concerns raised in the early part of the 20th century about the
rate of consumption of our natural resources and the impact of industrialization upon the environment, there was little concerted international efforts to either look at it in detail or to attempt to address the concerns.
Early environmental awareness
In the early 50s we saw the first real attempts to clean up our environment mainly in terms of attempting to deal with major sources of pollution. Cities, such as London in the UK, began to introduce the use of “smokeless fuels” to replace the use of traditional coal burning fires in an attempt to address the impact of the dreaded “London Smog.” There were also attempts to clean up old industrial sites and many of the highly polluted waterways that had become effectively open sewers moving industrial effluent to the seas.
The 60s and early 70s saw concerns being expressed about the growth of world population and the ability of the world to address the resultant food needs. One of the first influential reports to begin to pull these issues together and to relate it to the issue of available energy appeared in the early 70s. This was the
publication of the Club of Rome Report (Meadows, 1972) entitled “Limits to Growth” which brought together a group of international experts to look at “the
current and future predicament of man.” Most of the report was based on the results of a computational model that was developed to model the complex interplay between approximately 90 of the key variables that constituted their world model. These variables included population growth, industrialization changes, food production, resource consumption, pollution generation, and the availability of capital. At that time, the major per capita consumers of energy were the US, Canada and Sweden.
The rise of energy concerns
The early to mid 70s also saw the first real concerns about the long-term
availability of energy to meet the world’s demands. In the short term, there were significant increases in the cost of basic fuels following the Arab oil embargo and the limited availability of some of the traditional sources of petroleum-based fuels. At the same time there was growing concern about the widespread use of
nuclear power and the increasing dependency upon it as a primary source of energy. Although many of these concerns were focused around the long term environmental risks associated with its use, many governments saw it as their only viable means of meeting their society's growing energy demands.
Governments' response
At this point in time, the main response was to look at demand side management as the best means of controlling society's demand for energy although there was also a certain amount of new research initiated into alternative sources of energy, including solar, geothermal and wind. The focus of much of the “demand side management” (DSM) approach that governments adopted was on better
utilization of existing energy sources and there was relatively little thought of the impact of our energy use upon the environment.
In many countries around the world, particularly the developed nations in northern and temperate zones, governments were seeking quick and easy means of implementing some of the DSM measures. At this time, we see the first introduction of government measures to increase the fuel economy of
vehicles and governments also began to look at the construction industry, one of the major energy users consuming between 35-40% of energy in most developed countries, as another means of decreasing fuel use. Most of these early
measures in the construction industry utilized the building codes as a method of introducing these measures. The measures were mainly focused on reducing energy losses from buildings and introduced minimum levels of insulation and other related measures. These were often linked to incentives for upgrading existing buildings to meet these or higher standards.
This period also saw the development of a number of much more comprehensive energy guideline documents that were focused on achieving significantly higher levels of energy efficiency in buildings. Most of these were voluntary in nature,
although there has been a growing trend over the subsequent thirty years to incorporate many of these measures into the existing construction codes.
Climate change
Awareness of the broader impact of human activities on the planet's climate began to emerge in the 80s and 90s and, among other initiatives, resulted in the Kyoto Protocol to the Framework Convention on Climate Change being signed by many of the world governments since 1997. The Framework deals with a broad range of climatic issues including the Montreal Protocol on ozone depleting materials, but the Kyoto Protocol focuses on the emission of greenhouse gases with governments making binding commitments to reduce their greenhouse gas emissions in an attempt to address the threat of climate change.
Although there is clearly some significant changes in the world's climate from that which has been experienced over the last couple of centuries, there is still some controversy as to whether what we are seeing is just the normal variation that can be expected over a broader time range or whether these changes are the result of the impact of human activity on this planet. Even so, it is clear that, as a planet, we need to begin to moderate some of the impacts that we are having on our environment including the generation of greenhouse gases.
Government approaches to greenhouse gases
With the majority of our energy sources involving, either in its generation or use, the creation of greenhouse gases, most of the measures that governments are focusing on are related to energy usage. With the construction industry in many countries consuming 35-40% of the total energy usage, this sector has become a key one in government’s attempts to meet or exceed their Kyoto targets for
greenhouse gas reduction (GGR). In the construction sector, these approaches have usually built on more sophisticated approaches to energy usage and
conservation within buildings. There have though been some attempts to look at the broader issue of embedded energy within buildings (such as rating materials on the basis of the energy used in their life cycle) although this approach has not as yet been widely adopted.
APPROACHES TO REGULATION IN THE
CONSTRUCTION SECTOR
For the remainder of this paper, I am going to look in more detail at a few countries that have implemented various approaches to energy conservation within buildings and to reflect upon the interplay between the approaches and the regulatory environment in which they are implemented. For although many of the approaches may seem to be the same, their impact can be significantly different given the differences that exist in the physical and regulatory environments in each of the countries concerned.
There are though a few concerns that seem to exist independently of the country concerned. For example, in most countries, the housing sector has expressed concerns about regulatory approaches that would require individual changes (to account for house orientation and solar gains/losses etc.) for each house of the same pattern within a housing development site.
One of the key differences that we find among the countries is the degree to which they have implemented performance-based approaches to building regulation and the degree to which they have provided both prescriptive and performance approaches to achieving compliance with the requirements. There are also variations between the blend of regulated minimum performance
requirements and voluntary/incentive best practice approaches to deliver a better product (more energy efficient structure).
England and Wales (UK)
The building code in England and Wales is basically a performance-based code in which a set of functional requirements is established to provide for the health and safety of people in and around buildings. One section of this regulation (Part L) addresses the conservation of fuel and power. The requirements in the
regulation itself are specified in qualitative terms, e.g.
L1. Reasonable provision shall be made for the conservation of fuel and power in buildings by:
(a) limiting the heat loss through the fabric of the building;
(b) controlling the operation of the space heating and hot water systems; (c) limiting the heat loss from hot water vessels and hot water service
pipework:
(d) limiting the heat loss from hot water pipes and hot air ducts used for space heating;
(e) installing in buildings artificial lighting systems which are designed and constructed to use no more fuel and power than is reasonable in the circumstances and making reasonable provision for controlling such systems.
And although they are not all applicable in all contexts, e.g., Requirements L1(a), (b), (c) and (d) apply only to (a) dwellings; (b) other buildings whose floor area
exceeds 30 m2,
the requirements are general in nature and do not specify specific levels to be achieved.
Guidance on how the regulations can be met are provided in a set of “Approved Documents” that outline ways which, if followed by an applicant, can be accepted as complying with the building regulation – although following these guidances does not necessarily guarantee an acceptable design. As well as providing some clear prescriptive approaches that can be followed, the Approved Document also offers the opportunity of submitting an alternative solution that meets the
requirements. The alternative solution approach does provide for a fully performance-based solution.
The prescriptive approach offers three alternative methods of showing compliance for both dwellings and buildings other than dwellings. These methods are not totally the same for both classes of building. In dwellings, the methods are:
a) the Elemental Method;
b) the Target U-values Method; and c) the Energy Rating Method.
In the case of buildings other than dwellings the three methods are: a) the Elemental Method;
b) the Calculation Method; and c) the Energy Rating Method.
In addition, there are a number of prescriptive provisions that all buildings must meet that deal with issues such as: thermal bridging around openings; limiting infiltration; space and water heating system controls; insulation of vessels, pipes and ducts; and in the case of non dwelling buildings, lighting.
Elemental Method
Under the Elemental Method, certain building elements such as roofs, walls, floors, windows and doors, etc. must achieve a minimal thermal transmittance (U-value) as specified in the Approved Document. In the case of dwellings, there are differences in the specified U-values depending on the target Standard Assessment Procedure (SAP) rating that the building is expected to meet. SAP is an approach that has been taken in the UK to provide prospective purchasers and tenants of new buildings with an indication of the annual energy costs. The SAP rating goes from 1 (worst) to 100 (best) and takes into account the building’s dimensions, fabric thermal resistance, ventilation, heat losses and gains, water heating, weather conditions, space heating and fuel costs.
Once a U-value is determined, a designer can refer to Appendix A of the Approved Document to select a construction system that is deemed to provide the required U-value. These tend to be generic values for the various material types and designers often use more specific values from manufacturer's data sheets.
Target U-value Method (Dwellings only)
This approach requires that the designer establish a target U-value for their building using a formula that takes into account the floor area of the building in relation to the total area of exposed elements. Again, there are two versions of
this formula depending on the SAP rating for the building (≤ 60 or >60).
Having established the target U-value, an average U-value is then obtained by summing the values of all of the exposed surface areas. If the average U-value is less than the target U-U-value then the design is considered to be in compliance with the requirements.
Energy Rating Method (Dwellings only)
The Energy Rating Method is again built on the SAP approach and as such takes into account many more aspects of the building other than just the building
envelope. SAP incorporates a broader range of components including ventilation rates, solar gains/losses, climatic conditions, space and service water heating, and the cost of fuel. As such, it provides a more holistic picture of the building's energy efficiency.
Under the Energy Rating Method, a building must achieve a rating greater than 80 to 85 (exact criteria depends upon the floor area of the dwelling) in order to be considered as complying with the requirements of the code.
Calculation Method (Buildings other than dwellings)
In this method, a rate of heat loss is calculated for a “notional” building that complies with the elemental method and is the same size and shape as the proposed building. The “notional” building calculation uses default area
percentages of windows, doors and roof lights to calculate the rate of heat loss as per the Elemental Method. The rate of heat loss for the proposed building is then calculated taking into account the actual areas of each of these
components. To comply, the proposed building's rate of heat loss cannot exceed the rate of heat loss from the “notional” building.
Energy Use Method (Buildings other than dwellings)
This approach focuses on calculating the overall annual energy consumption of the building and compares it against the annual energy consumption of a similar reference building that complies with the Elemental Method. Again, to comply, it cannot exceed the annual energy consumption of the reference building. As this approach takes into account solar and internal energy gains, it provides another area of flexibility over the elemental and calculation methods.
Canada
Canada, like Australia, has responsibility for building and fire codes established at the Provincial and Territorial levels with each Province and Territory being responsible for legislating its own Codes. The Provinces and Territories have agreed to adopt a single set of Model Code Documents that are developed through a Commission (Canadian Commission on Building and Fire Codes – CCBFC) made up of representatives from all affected groups across the country. The National Research Council (NRC) of Canada supports the Commission, both technically and administratively, in a way similar to the ABCB. Under the
commission are a set of technical committees made up of experts from industry, regulators, public interest groups, academics and researchers. The technical committees are responsible for establishing the technical requirements within the codes.
Up until now, the Canadian Codes have generally been prescriptive-based with some performance requirements, mainly in the structural areas of the codes. Canada is about to adopt a set of objective-based codes that are in many ways similar to the Australian Codes in that there are sets of high-level objectives established for the documents with associated functional requirements that provide more explicit expectations. At the present time, these requirements are qualitative rather than quantitative. Associated with these requirements are sets of acceptable solutions, which, for now, represent the level of performance required by the codes.
Energy provisions
The National Building Code of Canada has traditionally had provisions within it that establish minimal requirements for insulation and other similar areas that relate to the suitability of the building for the activities to be undertaken within them. There were some changes in these areas during the energy crisis of the 70s but, with the introduction of new materials, technologies, and techniques, greater levels of energy efficiency can now be achieved at similar costs. Energy codes
In the early 90s, the CCBFC was approached by various levels of government (Provincial, Territorial and Federal) to develop a set of model energy codes suitable for adoption across the country. NRC had developed some similar guideline documents in the late 70s but they were not taken up for enforcement by any jurisdiction at that time. Two new model energy codes were developed and published in 1997. They were:
• the Model National Energy Code of Canada for Houses (MNECH); and • the Model National Energy Code of Canada for Buildings (MNECB). These two documents established a set of minimum requirements for energy efficiency measures in buildings. These measures are based on a cost-benefit approach that takes into account regional considerations such as material costs and availability, availability of fuel types and their costs, construction costs, and climatic considerations. An extensive data collection exercise underpinned the development of the cost and climatic data that was used to establish the
requirements.
Where buildings have conditioned space (heated or cooled), requirements have been established to address the building envelope and HVAC systems. The underlying philosophy here is to reduce the energy flow between the building and the environment. In addition, there are requirements that address the electrical power system, lighting, and service water heating. Generally, these
requirements apply to all types of buildings with some minor variations.
At the present time, adoption of these Model Codes has not been uniform across the country and, in some jurisdictions where they have adopted a code, they may have only adopted one and not the other.
Code Requirements
There are set of general provisions/procedures, which are similar for both the MNECH and MNECB that are used in determining the energy efficiency
requirements. They include: climatic data; the thermal transmittance values of materials; method of determining solar heat gain coefficients for windows; formula for calculating areas and applying concessions; and various referenced documents.
The mandatory measures are also similar for each code in that they address the building envelope; lighting; service water; electrical power and motors; and HVAC systems. Areas of these codes have both prescriptive and performance paths that can be used in meeting compliance. In the case of the MNECH, the
performance options exist only for the building envelope and HVAC components, whereas in the case of the MNECB, the performance options include the HVAC systems, building envelope, SWH systems and lighting.
In the case of the building envelope, the requirements address issues such as insulation and its continuity, air leakage and energy rating of windows and doors, and the air tightness of the building envelope itself. With lighting, the main focus is on internal lighting although it also addresses external lighting. These lighting provisions are more extensive in the MNECB and this is generally the case with the provisions dealing with the SWH system, electrical power and motor systems as well as the HVAC systems.
The prescriptive approach makes some provisions for designers to exercise various trade-offs in meeting the requirements of the codes. There are generally two types of trade-offs permitted: a simple trade-off and a computer-assisted trade-off. For example, the simple trade-off permits the effective thermal resistance of one or more components of the building envelope to be less than the prescriptive requirements provided the effective thermal resistance of the other components are increased. The computer assisted trade-off method uses software that permits more complex trade-offs to be performed.
The performance path to compliance is based on the use of specified modeling software that permits a comparison to be made between the energy use over a typical year of the structure under consideration and the energy use of a
reference building similar to the building under consideration but which complies with the prescriptive provisions of the code. In effect, the reference building provides a custom-made annual energy target that has to be met or exceeded by the design. There are some limitations on what is permitted to be traded off in meeting the buildings energy target and, in the case of the MNECH, the
performance option is limited to the building envelope and HVAC systems. In the case of the MNECB, the use of this approach is extended to include the lighting and SWH systems.
In the use of the performance options, account is taken of the costs of the different types of fuels in the different regions of the country and appropriate adjustments are made to account for this.
United States of America
In the USA, jurisdiction over building-related codes is established at the State level although, in a number of States, this is further delegated to the county or city level. At the present time, there are two major organizations writing model building codes: they are the International Codes Council (ICC) and the National Fire Protection Association. The ICC, formed in 1994, has been formed out of three previous code-writing bodies: Building Officials and Code Administrators International, Inc. (BOCA), International Conference of Building Officials (ICBO), and Southern Building Code Congress International, Inc. (SBCCI).
In terms of codes directly related to energy conservation, there are two main ones in use within the USA: the American Council of American Building Official's Model Energy Code (MEC) responsibility for which has now switched to the ICC and which has become the International Energy Conservation Code (IECC), and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) with their American Standard ANSI/ASHRAE/IESNA Standard 90.1-89 - Energy Code for Commercial and High-Rise Residential Buildings.
The MEC mainly addresses residential buildings such as single-family homes and multi-family residences that are three stories or less. It does address commercial construction but this is mainly through reference to ASHRE 90.1. ASHRAE 90.1 has been developed to address the needs of commercial and high-rise (four stories or greater) residential construction.
Although these codes have been adopted in many States, there are also other federal agencies, which have made reference to them, such as the Department of Housing and Urban Development (HUD), who require their funding recipients to comply with these codes/standards.
Approaches to Energy Conservation The Model Energy Code
As with many other energy codes, the MEC focuses on the building envelope although it also deals with requirements for HVAC and SWH systems as well as the electrical system. It has a set of basic mandatory requirements that all buildings must comply with which applied to the heating and cooling systems (including ducts), hot water systems, and electrical systems. Other requirements apply to material and equipment identification (to facilitate determination of
compliance) and to sealing of the building envelope.
Over and above the basic mandatory requirements, the MEC provides three options for demonstrating compliance: a prescriptive approach; a trade-off approach; and a software compliance approach. The prescriptive package approach involves minimal calculations and is the simplest method for
demonstrating compliance with the elements of the building envelope. These are basically table driven options that are established to take into account climatic zones and vary their requirements depending on the glazing area and its U value,
the R-values of the building envelope components, and the efficiency of the heating and cooling systems.
The trade-off approach adopts the frequently-used approach of comparing the proposed building against a standard reference building that meets the
prescriptive requirements. In the case of the MEC, it allows for trading off
components of the building envelope (floors, walls, ceilings, windows and doors) but not the HVAC components. In this system, each component of the building envelope is ascribed a U-value which is multiplied by the area of that component to give a UA value for that component. These components are summed to obtain a UA value for the whole building and this is then compared to the UA for the standard building within the same climatic zone as the proposed building. If the UA of the proposed building is less than that of the reference building then the building is deemed to comply.
Using the software compliance approach is similar to the trade-off approach although it is more comprehensive. This includes making allowance for the use of trade-offs where high efficiency equipment is used. With the use of this approach, there is also a provision for a more performance-based approach where the total annual energy consumption of the proposed building is compared against a building that complies with the UA method.
The International Energy Conservation Code
For residential buildings, the code offers two methods of demonstrating
compliance: the Annual Energy Consumption Method; or the Building Envelope Method. The Annual Energy Consumption method requires the calculation of the building's total annual energy usage using methods and formulas from the
ASHRAE Fundamentals Handbook and this takes into account the entire building and its energy using sub-systems. If the calculated annual value is less than that for a similar “Standard building” then the proposed building is deemed to comply with the code. This approach allows considerable flexibility in the design of the building and its individual components.
Although with the Building Envelope Method the main focus is on the building envelope, there are also a number of mandatory requirements that specify specific measures to be taken with regard to the HVAC and HWS systems as well as issues addressing the electrical and lighting systems.
Under the Building Envelope Method, restrictions are placed on energy loss by transmittance through the building envelope. It uses calculations of the U-values for the floors, walls and roofs as well as R-values for heated and unheated slabs, crawl spaces and basement walls. In undertaking the calculations, account is taken of the heating degree-days of the zone in which the proposed building is to be built as well as the R-values of the components and heat capacity of the walls, etc. These establish the set values for the proposed building that must be
achieved using one of four procedures. These procedures are: compliance by performance on an individual component basis; compliance by acceptable practice on an individual component basis; compliance by prescriptive
specification on an individual component basis; and compliance by total building envelope performance.
In the case of commercial buildings, there are two options available: by following the design of a commercial building by acceptable practice as detailed in the code or through compliance with ASHRAE/IESNA Standard 90.1-89 - Energy Code for Commercial and High-Rise Residential Buildings.
The use of the first option is currently limited to commercial buildings of less than four stories and having less than 50% of the gross wall area above grade glazed. It also provides for a mixed approach to compliance with some aspects of the building meeting the code, such as lighting, and others being met by meeting the requirements of ASHRAE/IESNA 90.1. In the code, R-values are specified for all building envelope components and are established for each component within a specific climatic zone, for different percentages of glazed wall area (up to the maximum) and for different construction types with specification of material types for certain components. There are also prescriptive requirements for HVAC and SWH systems as well as for lighting that must be met by a compliant design. ASHRAE/IESNA Standard 90.1 - Energy Code for Commercial and High-Rise Residential Buildings
The standard sets out a set of minimum basic requirements for a building system that must be complied with and they address: the building envelope; HVAC and SWH systems; electrical power; lighting; energy management; and the
distribution of energy. It also establishes mandatory requirements for air leakage and the thermal resistance of below grade components, etc.
This standard offers two methods of compliance: the Systems/Component Method or the Building Energy Cost Budget Method (see Figure 1). Within the Systems/Component Method, there are a further two optional approaches: the Prescriptive Criteria approach; and the Systems Performance Criteria approach. Under the Systems/Components Method, the Standard provides for prescriptive requirements for HVAC and SWH systems and the use of either prescriptive requirements or performance criteria for the building envelope, and lighting components.
With the Prescriptive Criteria approach, the standard provides, for each climatic zone, tables of maximum thermal transmittance U-values for the below grade surfaces, floors, external walls, and roof. There is little flexibility available to the designer using this approach. With the Systems Performance Criteria approach, there is a little more flexibility as it can be used to address both the building envelope and lighting components; all other components must comply with the prescriptive criteria. This method allows for the use of a computer program to undertake calculations of the external walls and fenestration and allows for the use of slightly different U-values for the floors, below grade walls and roof. This approach is also applicable in determining the lighting power allowance using another software package.
Figure 1. Compliance paths in for ASHRAE/IESNA Standard 90.11
Finally, there is the Building Energy Cost Budget Method of achieving compliance with the Standard. This is the most flexible of the methods of demonstrating compliance with the requirements of the standard and is based on the use of energy cost as the common factor in the assessment. It provides for the
development of innovative energy conservation designs that utilize passive solar heating, thermal storage, heat recovery, day-lighting, off-peak electricity, etc. Again, this method generally uses the comparison between the annual energy costs of the proposed building and a reference building that is similar in size and usage and which meets all the requirements of the prescriptive and performance requirements of the System/Component Method.
1
Figure reproduced from “International Survey of Building Energy Codes”. Australian Greenhouse Office, Canberra, Australia
The calculations undertaken in this method step through the calculation of the monthly energy consumption of both the proposed and reference building and then convert the consumption into the local energy costs for the fuels being consumed. These monthly costs are then summed to provide annual energy costs for both the reference and proposed buildings. To achieve compliance using this method, the annual energy costs of the proposed building must be less than that associated with the reference building.
ASHRAE/IESNA Standard 90.1 is referenced by a number of different authorities around the world as one way of demonstrating compliance with their specific energy regulations. For example, in Canada, the Province of Ontario calls it up in their code as an appropriate method of demonstrating compliance for buildings other than residential buildings.
CONCLUSIONS
With more countries signing up to the Kyoto protocol, there is a growing interest around the world in enacting energy conservation legislation as one tool for reducing the production and impact of greenhouse gases. As has been shown in this paper, the existing approaches have tended to concentrate on increasing the effectiveness of our energy utilization. Most of the simple approaches have concentrated on measures aimed at improving the energy performance of the building envelope.
Increasing the efficiency of the HVAC and SWH systems has also been a secondary target of many approaches along with measures aimed at increasing the efficiency of electrical and lighting systems. There has been relatively little focus on such things as solar gains and losses although this is an option in a few of the approaches. The failure to make full use of this is probably due to the difficulties that these would pose to many developers where existing constraints on the building orientation would preclude making use of these options.
Most regulators are challenged by the often-competing demands on one side to provide regulations in the form of simple, often prescriptive, cookbook solutions and on the other hand, to provide the designer with the ultimate flexibility in meeting the objectives of the regulations. We have seen in many of the approaches that have been taken around the world that there have been two different approaches taken to overcome, to some extent, these difficulties. In one case, the use of trade-offs amongst different components and areas within
prescriptive requirements has introduced the possibility of a reasonable level of design flexibility. The other one is the growing trend to include the use of software tools as a means of demonstrating compliance. Unfortunately though, there seems to have been little attempt to provide systematic validation of these software tools as they are often built on models developed with limited data. The result can be that some of the proposed innovative designs extend outside the range over which the model/software has been validated.
In most jurisdictions, residential and commercial buildings tend to have been dealt with using slightly different approaches. We tend to see a predominance of
prescriptive approaches applied to the residential sector and a greater reliance on performance-type approaches applied in the commercial sector.
Fuel costs, and in some cases the cost of materials and construction costs, are often factored into the calculations along with climatic information. In larger countries, these costs are often split into a number of regions, as in the case of Canada. Likewise, in some countries, there may be but a single climatic zone identified whereas in others there may be considerably more. The need to make these finer adjustments is often critical to the long-term acceptance of the
measures.
Although most of these regulations in these countries are established to deal with the majority of buildings, there are usually a variety of exemptions. These
exemptions from the requirements are usually for very small buildings or
buildings consisting of unconditioned spaces with little or no energy consumption. In many cases, these are barns or similar structures consisting of unconditioned spaces and used for storage, etc.
We have seen a quite widespread use of a comparison between a proposed building design and a “reference” building that is similar in all important ways (the ways in which they are similar do vary between countries but usually involve the building's size and use) to the proposed building but which conforms to the
prescriptive criteria. In most cases, the comparison metric that is used is in terms of annual energy costs. As we begin to see countries attempt to get away from heavily polluting energy sources in favor of “green” energy, it is probably that they will begin to penalize solutions based on the use of the more polluting energy sources.
Most of the focus of this paper has been on the use of regulated solutions to energy conservation. Where regulation has not been taken up, there has been some evidence of other, non-regulatory agencies, establishing requirements, often using reference to energy conservation Standards, for support through their programs. For example, the US Department of Housing and Urban Development (HUD), who require their funding recipients to comply with the energy
conservation measures.
Other countries have put in place voluntary programs and guidance documents but the take-up of these have been relatively patchy. Some utilities, faced with existing legislation which requires them to provide power to their consumers, and who are faced with major investments to meet the growing demand, have
instigated voluntary incentive programs to reduce power demands through energy conservation programs.
BIBLIOGRAPHY
Australian Building Codes Board, 2000. “International Survey of Building Energy Codes”. Australian Greenhouse Office, Canberra, Australia
Meadows, D.H., 1972, “The Limits to Growth: a report for the Club of Rome’s project on the predicament of mankind” Universal Books, N.Y., N.Y.
The Inter-jurisdictional Regulatory Collaboration Committee, 1998. “Guidelines for the Introduction of Performance Based Building Regulations”. Australian Building Codes Board, Canberra, Australia.
