Objectives of Elemental
Estimation
1. To reveal the distribution of costs among the
constituent element of the project.
2. To relate the cost of any constituent element to its
importance as a part of the whole project.
3. To compare the cost of the same element in
different projects.
4. To enable a determination of how costs could have
been allocated to obtain a better project.
5. To obtain and use cost data for future projects.
Ratio Used for Elemental
Estimation
1.Element quantity to base unit quantity
2.Element cost to total project cost
Sample Ratios in Building Element
Estimates :
Laboratory and office Building
Design Efficiency
Areas
Area of exterior vertical cladding to floor area
Ratios
0.8244 : 1
Area of windows to area
of exterior vertical cladding
Area of windows to gross floor area
0.1156 : 1
0.0951 : 1
Area of roofing to gross floor area
0.5113 : 1
Area of partitions to gross floor area
0.9618 : 1
Area of internal doors to area of partitions
0.0724 : 1
Area of floor finish to floor area
1.0023 : 1
Area of ceiling finish to floor area
0.9369 : 1
Volume of building to gross floor area
11.9669 : 1
Building An Element Cost
From Unit Cost Data (Analysis)
Element: 3a. Exterior cladding: roof finish
12.7-mm gypsum board
4-ply built-up roofing
75-mm rigid insulation
40-mm stone
Expansion joints, including:
Flashing and butyl
membrane
Flashing at parapet
ElementCost 
Quantity
16,140 ft2
16,140 ft2
16,140 ft2
1,305 tons
Unit
Cost*
$ 0.85
1.26
1.41
50.00
L.S.
490 m2
—
30.00
$73,447
 $4.55 / ft 2
16,140
Cost
$ 5,652
21,980
22,765
6,350
2,000
14,000
$73,447
*September 1981 cost level.
Substructure
a. Normal Foundations. Footing to extend to 4 ft
below average finish grade with finish grade at an
average of 1 ft below top of foundation walls.
Allow for footing size 2 ft  4 ft and foundation
wall 10 in. wide and 5 ft high.
b. Basement excavations and backfill. Not
applicable.
c. Special foundations. Not applicable.
Element
Substructure
a. Normal foundations
b. Basement
excavations and backfill
c. Special foundations
Ratio to
GFA
Quantity
0.5000
125,000
Unit Unit Cost Sub-total
ft2
5.6
Elem.
Total
700,000
Elem.
Cost/ft Cost/ft 2
2
Percent
2.80
ft2
0.00
ft2
0.00
700,000
2.80
3.8
Substructure
a. Lowest-floor construction. Plain slab 6-in.-thick
concrete, including 8-in. of crushed stone, mesh
reinforcing, screed and steel trowel finish.
b. Upper-floor construction. Steel frame, metal floor
deck, joint formwork.
c. Roof construction. Steel frame, including 11 2-in.deep galvanized metal deck.
Element
Structure
a. Lowest-floor construction
b. Upper-floor construction
c. Roof construction
Ratio to
GFA
Quantity
0.5000
0.5000
125,000
125,000
0.5102
127,550
Unit
ft2
ft2
ft2
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
2.23
9.20
278,750
1,150,000
1.12
4.60
6.58
839,279
3.36
2,268,029
9.07
13.1%
Exterior Cladding
a. Roof finish. Build-up roof system, including wood cants, nailers,
flashings, and 2 in. of rigid insulation for low-rise building.
b. Walls below ground floor.
c. Walls above ground floor. 12-in. composite wall with 4-in. modular
brick facing, vapor barrier, 6-mm metal stud, 4-mm batt insulation,
metal furring, and drywall.
d. Windows. Aluminum frames with baked enamel finish. Thermally
broken with one operable vent and sealed tinted double glazing.
e. Exterior doors and screens. Aluminum framing with baked enamel
finish thermally broken, sealed double glazing.
Element
Exterior cladding
a. Roof finish
b. Walls below ground floor
c. Walls above ground floor
d. Windows
e. Exterior doors and screens
Ratio to
GFA
0.5102
0.0000
0.8861
0.1446
0.0136
Quantity
Unit
127,550
ft 2
221,525
36,150
3,400
ft 2
ft 2
ft 2
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
5.36
0.00
17.29
34.76
38.70
2.73
0.00
15.32
5.03
0.53
683,668
0
3,830,167
1,256,574
131,580
5,901,989
23.61
34.2%
Interior Partitions
a. Permanent partitions. Metal stud partitions, 4-in.
thick with a single layer of 1 2-in. drywall on both
sides. 8-in. concrete block fire walls with metal
furring and drywall either side.
b. Movable partitions.
c. Doors. Hollow-steel honeycombed doors in 18 -in.
frames, including hardware for residential
buildings.
Element
Interior partitions
a. Permanent partition
b. Movable partitions
c. Doors
Ratio to
GFA
0.7007
0.0000
0.0025
Quantity
175,175
0
625
Unit
ft2
ft2
each
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
5.03
0
660
3.52
0.00
1.65
881,130
0
412,500
1,293,630
5.17
7.5%
Vertical Movement
a. Stairs. Metal pan stairs, 5 ft wide  10 ft rise with
half landings, including precast terrazzo treads and
landings and picket railings.
b. Elevator and escalators. Not applicable.
Element
Ratio to
GFA
Vertical Movement
a. Stairs
b. Elevators
0.00008
0
Quantity
Unit
20 flights
0 number
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
5700
0
114,000
0
0.46
0.00
114,000
0.46
0.7%
Interior Finishes
a. Floor finishes. Quarry tile in vestibule, ceramic
tile in washrooms, and vinyl acetate tile elsewhere.
b. Ceiling finishes. Acoustic tile throughout.
c. Wall finishes. Tape, fill, and paint.
Element
Interior finishes
a. Floor finishes
b. Ceiling finishes
c. Wall finishes
Ratio to
GFA
1
1
2.2874
Quantity
250,000
250,000
571,850
Unit
ft2
ft2
ft2
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
1.35
1.50
0.87
1.35
1.50
1.99
337,500
375,000
497,510
1,210,010
4.84
7.0%
Fittings and Equipment
a. Fittings and fixtures. Allowance to cover
washroom accessories, signs, and floor mats
($200,000).
b. Equipment. Not applicable.
Element
Fittings and equipment
a. Fittings and fixtures
b. Equipment
Ratio to
GFA
0
0
Quantity
0
Unit
each
each
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
0
200000
0
0.8
0
200,000
0.80
1.2%
Electrical
a. Services. Complete electrical installation,
including electric heating.
b. Lighting and power. Lighting throughout.
c. Systems. Not applicable.
Element
Electrical
a. Services
b. Lighting and power
c. Systems
Ratio to
GFA
1
1
0
Quantity
250,000
250,000
0
Unit
ft2
ft3
ft4
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
4.40
2.30
0.00
4.40
2.30
0.00
1,100,000
575,000
0
1,675,000
6.70
9.7%
Mechanical
a. Plumbing and drains. Allowance for residential
buildings.
b. Fire protection. One head per 120 ft2 ($190/head).
c. HVAC. Room top system, 0.0001 ton of cooling
per square foot of gross floor area.
Element
Mechanical
a. Plumbing and drains
b. Fire protection
c. HVAC
Ratio to
GFA
0.0022
0.0083
0.0010
Quantity
Unit
550 fixtures
2,075 hydrants
250 tons
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
2580
190
3800
1,419,000
394,250
950,000
5.68
1.58
3.80
2,763,250
11.05
16.0%
Overhead and Profit
• Allowance for simple commercial projects with
excellent market conditions.
Element
Overhead and Profit
Net building cost
Ratio to
GFA
Quantity
7%
Unit
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
1,128,814
17,254,722
Use 17,300,000 + 15%
4.52
6.5%
69.02 100.0%
Site Development
a. General. Rough grade, spread imported topsoil, fine grade, and
place sod. Roads and parking, including 6-in. of crushed stone
base, 3 in. of double-layer asphalt, and precast concrete curbs.
Walks and steps 4 ft wide, including 4 in. of crushed stone base,
5 in. of concrete, mesh and broom finish. Include a planting
allowance for trees and shrubs (allowance $250,000).
b. Mechanical and electrical. Site drainage and services to the
building (allow $100,000).
c. Alterations. Not applicable.
d. Demolition. Not applicable.
Element
Site development
a. General
b. Mechanical and electrical
c. Alterations
d. Demolition
Ratio to
GFA
0
0
0
0
Quantity
Unit
-
allow
allow
m2
m2
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
-
250,000
100,000
0
0
10.00
4.00
0.00
0.00
350,000
14.00
-
Contingencies
a. Design. Allow 6%.
b. Escalation. Allow 2%.
c. Construction. Allow 3%.
Element
Contingencies
a. Design
b. Escalation
c. Construction
Ratio to
GFA
Quantity
6%
2%
3%
Unit
Elem.
Unit Cost Sub-total Elem. Total Cost/ft Cost/ft 2 Percent
2
1,059,000
353,000
529,500
1,941,500
7.77
-
Element
Substructure
a. Normal foundations
b. Basement excavations and
backfill
c. Special foundations
Ratio to
GFA
0.5000
Quantity
Unit
125,000
ft 2
Elem.
Unit Cost Sub-total Elem. Total Cost/ft 2 Cost/ft 2 Percent
5.60
700,000
2.80
2
ft
ft 2
0.00
0.00
700,000
Structure
a. Lowest-floor construction
b. Upper-floor construction
c. Roof construction
0.5000
0.5000
125,000
125,000
0.5102
127,550
2
ft
ft 2
ft 2
2.23
9.20
278,750
1,150,000
6.58
839,279
0.5102
0.0000
0.8861
0.1446
0.0136
127,550
ft 2
221,525
36,150
3,400
ft 2
ft 2
ft 2
5.36
0.00
17.29
34.76
38.70
0.7007
0.0000
0.0025
175,175
0
625
ft 2
ft 2
each
5.03
0
660
0.00008
0
20 flights
0 number
5700
0
1
1
2.2874
250,000
250,000
571,850
2
ft
ft 2
ft 2
1.35
1.50
0.87
114,000
0
0
0
0
each
each
0
1
1
0
250,000
250,000
0
2
ft
ft 3
ft 4
4.40
2.30
0.00
200000
0
0.0022
0.0083
0.0010
Overhead and Profit
Net building cost
Site development
a. General
b. Mechanical and electrical
c. Alterations
d. Demolition
Contingencies
a. Design
b. Escalation
c. Construction
Total Building Cost
550 fixtures
2,075 hydrants
250 tons
2580
190
3800
0
0
0
0
-
6%
2%
3%
allow
allow
m2
m2
-
0.46
0.7%
4.84
7.0%
0.80
1.2%
6.70
9.7%
4.40
2.30
0.00
1,100,000
575,000
0
1,419,000
394,250
950,000
5.68
1.58
3.80
2,763,250
1,128,814
17,254,722
Use 17,300,000 + 15%
7%
7.5%
0.8
0
1,675,000
Mechanical
a. Plumbing and drains
b. Fire protection
c. HVAC
5.17
1.35
1.50
1.99
337,500
375,000
497,510
200,000
Electrical
a. Services
b. Lighting and power
c. Systems
34.2%
0.46
0.00
1,210,010
Fittings and equipment
a. Fittings and fixtures
b. Equipment
23.61
3.52
0.00
1.65
881,130
0
412,500
114,000
Interior finishes
a. Floor finishes
b. Ceiling finishes
c. Wall finishes
13.1%
2.73
0.00
15.32
5.03
0.53
683,668
0
3,830,167
1,256,574
131,580
1,293,630
Vertical Movement
a. Stairs
b. Elevators
9.07
3.36
5,901,989
Interior partitions
a. Permanent partition
b. Movable partitions
c. Doors
4.1%
1.12
4.60
2,268,029
Exterior cladding
a. Roof finish
b. Walls below ground floor
c. Walls above ground floor
d. Windows
e. Exterior doors and screens
2.80
250,000
100,000
0
0
11.05 16.0%
4.52
6.5%
69.02 100.0%
10.00
4.00
0.00
0.00
350,000
14.00
-
1,941,500
19,591,500
Use 19,600,000 + 15%
7.77
78.37
-
1,059,000
353,000
529,500
Estimate note: The total cost
is within the range predicted
by the preliminary estimate
(19,000,000+25%)