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FiRECAM<TM> Economic Model (ECMD)
Ser TH1 R427 no. 723 c. 2 BLDG
National Research Conseil national
1+1
Council Canada de recherches CanadaC I S 1 l / I C L S T NRC/CNRC I R C Ser
Received on: 01-08-97 I n t e r n a l r e p a r t .
by G.V. Hadjisophocleous and B.L. Yager
r e p o r t ( I n s t i t u t e t
Internal Report No. 723
ABSTRACT
This report describes the Economic Model of the NFL risk-cost assessment model,
FiRECAWM. The Economic Model is used to calculate the capital costs of building components and fire protection equipment, as well as the annual costs of component replacement,
TABLE OF CONTENTS
1
.
INTRODUCTION...
12
.
ECONOMIC MODEL SUMMARY SHEET...
2...
.
3 DESCRIPTION OF MODEL 3 3.1 Major Assumptions Used in Modelling...
3...
3.2 Cost Calculations 3...
3.2.1 Get Building & Protection System Characteristics 4...
3.2.2 Get Cost of Building and Protection System Components 5...
3.2.3 Calculate Capital Cost of Building Construction 5...
3.2.4 Calculate Capital Cost of 13nishes 7...
3.2.5 Calculate Capital Cost of Passive Fire Protection System 7...
3.2.6 Calculate Capital Cost of Active Fire Protection Systems 7...
3.2.7 Calculate Capital Cost of Emergency and Organizational Systems 8 3.2.8 Calculate Annual Maintenance Costs...
83.2.9 Calculate Annual Costs of Replacement
...
93.2.10 Calculate Present Worth of Costs
...
9...
3.2.1 1 Calculate Capital Costs for Use in Other Submodels 9 3.2.12 Output Costs to Database...
94
.
CALCULATIONS...
94.1 Calculation of Annual Cost of Component Replacement
...
94.2 Calculation of Present Worth Given Annual Cost
...
104.3 Calculation of Building Geometric Dimensions
...
104.3.1 Exterior Wall Lengths
...
104.3.2 Interior Compartment Separation Lengths
...
104.3.3 Compartment to Conidor Separation Lengths
...
115
.
MODEL INPUTS...
115.1 Building Layout
.
...
11. 5.1.1 Buildlng Material
...
115.1.2 Exterior Wall Material
...
125.1.3 Interior Wall Material
...
125.1.4 Floor and Ceiling Material
...
125.1.5 Stairshaft Wall Material
...
12. . 5.2 Alarm System Characteristics
...
125.3 Fire Suppression System Characteristics
...
12. . 5.4 Passive System Charactenstics
...
...
125.5 Smoke Control System Characteristics
...
125.6 Emergency & Organizational System Characteristics
...
125.7 Itemized Capital and Annual Costs of Components and Activities
...
135.8 Economic Factors
...
136
.
MODEL OUTPUTS...
13...
6.1 Data Sent to the Output Reporting Facility of FiRECAMTM 13 6.2 Output Required for Other FiRECAMTM Submodels...
14FiRECAiWM
Economic Model (ECMD)
by
G.V. Hadjisophocleous and B.L. Yager
1.
INTRODUCTION
The Economic Model is used to calculate the costs pertaining to building construction, installation of active and passive fire protection systems, and maintenance and organizational activities incorporated in the management of
a
building. In order to calculate these costs, a significant amount of information on the layout of the building, the costs of building materials, and the costs of detection and suppression system components must be input from a current database of cost figures. These costs are summed and grouped into the following categories for output and later use by other FiRECAIWM submodels.Capital costs for building construction per floor Capital costs of passive fire protection per floor
Capital costs of active fire protection (detection, smoke control and suppression systems) per floor
Annual maintenance, organizational and replacement costs per floor Present worth of all annual costs
In this report, a number of terms, listed below, are used in a context slightly different than the definitions given in the National Buildimg Code of Canada [I] (NBCC) and the National Fire Code of Canada [2].
Compartment is used to define an enclosed space which contains combustible materials and has
well defined boundaries and openings for ventilation and smoke spread. A compartment in this submodel does not necessarily have fire-rated boundaries, as is defined in the NBCC [I].
Floor assembly is used to define the construction comprising the lower surface of a
compartment, which may or may not be fire-rated.
Floor in the context of this submodel means a storey as defined in the NBCC [I], i.e. that portion
of a building which is situated between the top surface of a floor assembly and the top surface of the floor assembly next above it, and if there is no floor above it, that portion between the top surface of such a floor assembly and the top surface of the ceiling above it.
Floor area in this submodel is the greatest horizontal area on any one floor within the outside
surfaces of the exterior walls.
This submodel is an integrated member of the FiRECAIWM model and uses many of the same graphical user interfaces to input the required data as used by the other FiRECAMTM submodels.
2. ECONOMIC MODEL SUMMARY SHEET
Table 1: FiRECAMT" Model Summary Sheet for Residential and Office Buildings Sub-model Objectives Methodology Main input Main output Economic Model
Calculate the capital costs of building components and fire protection equipment, as well as the annual costs of replacement, maintenance and organizational activities.
Using the building layout and types of fire protection equipment installed, the model retrieves and sums the costs of components in the building (including building components, fire protection system components and emergency system components), as well as maintenance and organizational activities.
Building layout
Itemized capital and annual costs of components and activities Alarm and detection system characteristics
Fire suppression system characteristics Passive fire protection system characteristics Smoke control system characteristics
Emergency & organizational system characteristics Economic factors
Total capital cost per floor Total annual cost per floor Basic construction cost per floor
FRR incremental cost per floor Construction cost per floor Annual maintenance costs Annual organizational costs Annual replacement costs
Present worth of total annual costs
Active fire protection systems capital costs Detection and alarm system capital costs Automatic suppression system capital costs Manual suppression system capital costs Smoke control system capital costs
Emergency system capital costs (lighting, exit signs) Organizational system capital costs
Capital cost of compartment of fire origin Capital cost of floor of fire origin
3. DESCRIPTION OF MODEL
The Economic Model calculates the main costs involved in the construction of a building and the installation of fire protection systems. These costs are in the form of capital costs at the time of construction and annual costs over the life of the building. The capital costs include the costs of construction and the capital costs of the fire protection systems, whereas the annual costs include the costs of replacement and maintenance of the active fire protection systems, and the annual costs of organizational procedures.
3.1 Major Assumptions Used in Modelling
Several assumptions are used in calculating the costs relevant to a specific building design. These include:
All floors have exactly the same layout and installed protection systems.
All comvartrnents on each floor are identical (have identical dimensions, construction materiais and protection systems, etc.)
Building has a rectangular floor plan.
Building with multiple compartments has one central comdor.
The capital costs of building construction components do not include the costs of upgrading the fire resistance ratings to the required level.
The cost of all labour, fees and permits are included in the itemized costs of the components. Annual fire drills, if used, occur once per year and have a duration of 2 hours.
If a local smoke detector alarni system is used, it is assumed that there is one detector per compartment.
All present values are at the time of building construction.
The prime interest rate and the rate of inflation remain fixed over the life of the building. The average cost of construction per unit floor area, if used, includes the cost of finishes 3.2 Cost Calculations
The calculation of the costs is broken down into the following steps and is summarized in the flowchart shown in Figure 1.
Submodel
Protection System
and Protection System
Calculate Capital Cost of Building Construction
.
Calculate Capital Costof Finishes
.
Calculate Capital Costof Passive Fire Protection System
.
Calculate Capital Cost.
of Active FireFigure 1: Economic Model Flowchart
3.2.1 Get Building & Protection System Characteristics Input:
Occupancy type (apartment or office)
Building constrnction materials (wood. concrete or steel)
Calculate Capital Cost of Emergency & Organizational Systems
i
Maintenance Costs Calculate Present Worth of Costs.
Calculate CapitalCosts for Use in Other
Ouput costs to Database
.
SubmodelAlarm and detection system characteristics (alarm type, location of detectors, etc.) Fire suppression system characteristics (number of sprinkler heads, extinguishers, etc.) Emergency system characteristics (number of emergency lights, etc.)
Organizational and management characteristics (number of floor plans, etc.) 3.2.2 Get Cost of Building and Protection System Components
Input:
Cost of building components (walls, stairs, etc.) according to occupancy type and material Cost of finish components (glazing, doors. etc.) according to occu~ancv
.
tvDe and material .AIncremental costs of passivefire protection, according to-fire resisiance rating of each component
Cost of alarm system components according to alarm and detection system type Cost of active suppression system components
r Cost of emergency systems (lighting, exit signs) and organizational systems (floor plans, training, etc.)
Replacement cost for components of active fire protection system Life expectancy of active fire protection systems components 3.2.3 Calculate Capital Cost of Building Construction
Calculates the capital cost of building construction (no fire protection systems, passive or active). The flowchart in Figure 2 outlines the methodology which is used to calculate this cost.
of Building Construction
separations ( # o f compartments
-
2 )Calculate Cost of Elevators Calculate cast of exterior
walls Calculate cast of compartment to corridor
separations
.
Calculate cost of fioor ceiling assemblyCalculate cost of Cost of structure = Stairshafts Floor Area ' Cast/mZ Calculate casts of service
shafts and garbage chutes balconies
calcuiate cost of columns
1
of Building Construction
As illustrated in Figure 2, there are two ways in which to calculate the cost of the building constmction components, either using the itemized elemental costs of the components themselves, or using an average cost per unit floor area for a building of the same construction type as the building being analyzed. In the latter case, none of the individual building elements are used to calculate the cost of the building construction; instead, the average value for the construction of the building is passed from the expert database.
3.2.4 Calculate Capital Cost of Finishes
Costs of doors: compartment entrance, stairwell, elevator Costs of exterior glazing: window and balcony
Note: If in the calculation of the capital cost of building construction, the average cost per unit floor area was used instead of the elemental costs of the components, the capital cost of finishes calculated in this section is assumed to be zero. This is because the cost of finishes is assumed to be included in that average cost.
3.2.5 Calculate Capital Cost of Passive Fire Protection System
This is the cost of upgrading the fire resistance rating (FRR) of the building components to a required level. This is quoted as a cost per unit in addition to the cost of the component itself, assumed to have no fire resistance. There is a choice of fire resistance ratings including 15,30,60,90, 120 or 180 minutes. The cost of passive fire protection is simply the sum of the incremental costs for all the constmction components listed below:
Exterior walls Fire stops
Conidor wall separations
Interior compartment separations Floor and ceiling assemblies Columns
Stairwell, staircase
Service shafts and garbage chutes
Doors (elevator, stairwell, compartment) Glazing
Note: If in the calculation of the capital cost of building construction above, the average cost per unit floor area was used instead of the elemental costs of components, the passive fire protection cost is calculated using an average cost per unit floor area. The expert database includes unit costs for various fire resistance ratings.
3.2.6 Calculate Capital Cost of Active Fire Protection Systems
The calculation of the capital cost of the active fire protection systems is the largest component of the cost calculation for the Economic Model. For each component installed, the capital cost is calculated on a per floor basis and summed to obtain the total capital cost for all active fire protection systems. The following costs are calculated:
s Capital cost of detection and alarm systems
-
Cost of alarm controls, panels and connections to fire department or central service-
Cost of horns, speakers, pull stations- Cost of smoke detectors and heat detectors in compartments, corridors, elevators, stairshafts, ducts and service shafts
Capital cost of automatic suppression systems
- Cost of connections to main water supply system
-
Cost of flow switches- Cost of sprinkler system pumps - Cost of sprinkler heads and piping
-
Cost of any other suppression systems Capital cost of manual suppression systems-
Cost of standpipe risers, cabinets and firehoses-
Cost of private fire hydrants- Cost of portable fire extinguishers - Cost of fire department elevators Capital cost of smoke control systems
- Cost of stairwell pressurization equipment - Cost of elevator shaft pressurization equipment
-
Cost of exhaust fans and ducts3.2.7 Calculate Capital Cost of Emergency and Organizational Systems Cost of emergency lighting and signs
Cost of posting floor aria emergency plans 3.2.8 Calculate Annual Maintenance Costs
The different types of alarm and protection systems, as well as the different types of maintenance schemes, means that several possibilities are needed for calculating the annual maintenance cost. There are four different ways that the management of a building may pay for maintenance activities: no maintenance is conducted, a 24-hour maintenance contract is
purchased; an in-house maintenance team is employed, or maintenance is conducted on an element by element basis. These four options are available in the FiRECAMTM Economic Model. If no maintenance is employed, the cost for maintenance is zero. If either the 24-hour contract or an in-house scheme is employed, the cost used is the cost retrieved from the FiREBASE database.
If the maintenance is calculated on an element-by-element basis, the annual maintenance costs of the following components are summed:
Alarm system - single stage, - 2 stage zoned, or - 2 stage addressable Smoke detectors Heat detectors Sprinkler system
Manual suppression system (extinguishers and fire hose cabinets) Smoke control system
Emergency systems (generators, lights)
Also included in the calculation of the annual cost of maintenance for all maintenance schemes, are the costs of:
Alarm system monitoring
Fire drills
Annual inspection
3.2.9 Calculate Annual Costs of Replacement
In the FiRECAWM interface shell, the user is given the option of including the replacement costs of the fire protection and alarm systems in the economic analysis. If this option is included, the following costs are calculated.
Annual cost of horn and speaker replacement Annual cost of smoke detector replacement Annual cost of heat detector replacement Annual cost of fire hose replacement
Annual cost of emergency light replacement Annual cost of exit sign replacement
The periodic replacement costs are converted to annual costs by using the expected life of the component and the calculations mentioned in Section 4.1.
3.2.10 Calculate Present Worth of Costs
All annual costs are converted to a present worth in order to compare them to the capital costs. The calculations used are shown in Section 4.2.
3.2.1 1 Calculate Capital Costs for Use in Other Submodels
The description of costs used by other submodels is contained in Section 6.2. 3.2.12 Output Costs to Database
The computed costs are stored in the output database of FiRECAMTM. A description of these output costs is contained in a following section.
All the above costs are calculated in dollars per floor using the assumption that all floors have similar layouts and installed systems. If in the case of a system which is not installed on a floor-by-floor basis (elevator cars, sprinkler pumps, etc.), the cost per floor is simply calculated by dividing the cost of the system by the number of floors that the current building design incorporates.
4. CALCULATIONS
As mentioned in previous sections, the methodology for calculating the economic costs of the building and the protection systems is generally very simple. In most cases, it consists of summing the costs of the components present. However, there are a few calculations which are used often in the Economic Model. These are described here.
4.1 Calculation of Annual Cost
of
Component ReplacementEach of the active protection system components has associated with it a period of
replacement which is the amount of time before a component must be replaced. The replacement of these components must be included in the annual costs of the fire protection systems, hence the periodic costs must be expressed in an annual form. The following formula is used to express the periodic replacement cost as an annual cost:
Periodic Cost
*
Discount Rate Annual Cost =(1
+
Discountate)^'^""'^^^'*
- 1where
Periodic Cost is the cost of replacing the component considered (includes component, labour and other fees)
Discount Rate is the prime rate minus the rate of inflation
Replacement Period is the time between replacements of the component
4.2 Calculation of Present Worth Given Annual Cost
In order to evaluate the annual and capital costs on an equal footing, the annual costs must be converted to a present worth. This is done using the following formula:
Annual Cost
*
(1 - (1+
Discountate)-"'^)
Present Worth =
Discount Rate where
Annual Cost is the recurring annual cost
Discount Rate is the prime rate minus the rate of inflation Life is the life of the building
4.3 Calculation of Building Geometric Dimensions
The Economic Model requires the geometric characteristics of the building. The lengths of the walls (external and internal) must be calculated so that an accurate value of the cost of the building can be estimated. The length of firestopping along the intersection of the walls and the floors or ceilings is also required.
4.3.1 Exterior Wall Lengths
The length of the exterior walls is the length of the building perimeter: Length of Ext. Wall = (building width
+
building length)*
2(the building is assumed to have a rectangular shape). 4.3.2 Interior Compartment Separation Lengths
The length of interior separations is dependent on the number of compartments, N, that are located on the floor of interest:
((N
-
2)*
Compartment Length for N > 2 Length of Interior Compartment Separations = 0 f o r N = 1 ( 4 )4.3.3 Compartment to Corridor Separation Lengths
Length of Compartment to Corridor Separations = Corridor Length
*
2 ( 5 )5. MODEL INPUTS
The greatest challenge to the Economic Model is the handling of the large set of data that is required to make an accurate estimate of the building and fire protection system costs. These costs are strongly dependent on the layout of the building and types of systems installed. These two factors, along with the actual costs of construction materials and individual protection
system components, account for the majority of the input passed to the Economic Model. All the input parameters will be described in a general fashion since a list and description of each
variable would be too extensive to include here.
The input data is entered in two different ways, depending on the application of the data element. The costs of the components and operations used in the building, as well as the replacement periods of each of the active protection system components, are maintained in an expert database, FIREBASE. The relevant data from this database is passed to the Economic Model for use in the calculations. Additional data required for the Economic Model is entered by the user. This data consists mainly of parameters relevant to building layout, installed systems and incorporated procedures.
5.1 Building Layout
Type of occupancy (apartment or office) Number of floors
Number of columns per floor Interior and exterior wall lengths Lengths of corridors
Floor dimensions (width, length, floor area)
Number, size and layout of compartments (apartment, enclosed office) Area of exterior glazing
Balcony layout
Number of garbage chutes, service shafts, elevator shafts and stairwells Construction material of interior walls, exterior walls, floors, ducts, stairs, etc.
The components used in the construction are grouped to reduce the number of input variables required from the user for construction material types. The costs in FiREBASE for the components in the following groups depend on the construction material type. Either concrete, wood or steel can be chosen for each group listed below.
5.1.1 Building Material Building frame Columns Balcony Elevator shaft Elevator car Elevator door
Garbage chutes and HVAC ducts Glazing
5.1.2 Exterior Wall Material Exterior walls
5.1.3 Interior Wall Material Compartment separations
Compartment to corridor separations Compartment entrance doors
Fire stops
5.1.4 Floor and Ceiling Material Floor assembly
Ceiling assembly
5.1.5 Stairshaft Wall Material Stairwell doors
Staircase Stairshaft
5.2
Alarm System Characteristics Alarm type (# of stages)Number of alarm system components (pull bars, detectors, speakers)
Number of smoke detectors and number of heat detectors in each: compartment; corridor; stair shaft; elevator shaft, service shaft; and garbage chute. The number of HVAC duct heat and smoke detectors in the building is also required.
5 3
Fire Suppression System CharacteristicsType and number of fire extinguishers
Type and number of manual suppression systems (standpipes, firehoses) Type of sprinkler system used (full coverage, partial coverage)
Number of sprinkler system components used (# of pumps, heads) 5.4 Passive System Characteristics
Fire Resistance Rating for exterior and interior walls Fire Resistance Rating for floor and ceiling assemblies Fire Resistance Rating for stairs
5.5 Smoke Control System Characteristics Whether stairshaft pressurization is used Whether elevator shaft pressurization is used
5.6
Emergency & Organizational System CharacteristicsTypes of emergency procedures and plans used (drills, inspections, floor plans, emergency olans. etc.)
kypes of emergency equipment (generators, emergency lights, etc.) Number of plans and procedures posted
5.7 Itemized Capital and Annual Costs of Components and Activities
Capital costs of building elements
Capital costs of finishing (compartment doors, windows, elevator doors)
Costs of upgrading fire resistance (floor assemblies, walls, stairs, etc.) to required rating Costs of alarm and protection system components (detectors, sprinklers, extinguishers) Annual costs of organizational training (fire evacuation training, etc.)
Annual costs of alarm system monitoring and maintenance
Replacement costs of active fire protection components (horns, detectors, lights, etc.)
5.8 Economic Factors
Building design life
Expected life of fire protection components Current prime and inflation rate
6. MODEL OUTPUTS
The output of the Economic Model can be divided into the following two categories.
6.1 Data Sent to the Output Reporting Facility of FiRECAMTM
The data sent to the output reporting facility of FiRECAWM include all the costs of the building and fire protection systems grouped into convenient categories. The costs are expressed as both the present value (at the time of building construction) and an annual cost.
Figure 3: Economic Model Screen Output 6.2 Output Required for Other FiECAhlTM Submodels
The Fire Cost Expectation [3] and Property Loss [4] submodels require variables from the Economic Model to estimate the cost of heat, smoke and water damage. These are:
Capital cost of compartment of fire origin
Capital cost of floor of fire origin (excluding compartment of fire origin) Capital cost for entire floor
The Economic Model assumes that every compartment has the same design, and calculates the capital cost of the compartment of origin simply by applying a ratio of the
compartment floor area and entire floor area to the capital cost of the entire floor. This value is subtracted from the capital cost of the entire floor to yield the capital cost of the floor of fire origin.
7.
REFERENCES
1. National Building Code of Canada 1995, Canadian Commission on Building and Fire Codes, National Research Council of Canada, NRCC No. 38726, Ottawa, Ontario. 2. National Fire Code of Canada 1995, Canadian Commission on Building and Fire Codes,
National Research Council of Canada, NRCC No. 38727, Ottawa, Ontario.
3. Hadjisophocleous, G.V. and Yager, B.L., 1996, FiRECAWM Fire Cost Expectation Model (FCED), IRC Internal Report No. 722, Institute for Research in Construction, National Research Council of Canada, Ottawa, Ontario.
4. Hadjisophocleous, G.V. and Yager, B.L., 1996, FiRECAiWM Property Loss Model (PLMD), IRC Internal Report No. 721, Institute for Research in Construction, National Research Council of Canada, Ottawa, Ontario.
