1. SIMPLE EEC CALCULATION METHOD FOR BUILDINGS BASED ON INPUT-OUTPUT ANALYSISE
Keizo YOKOYAMA, Tatsuo OKA, Noriyoshi YOKOO
Kogakuin University, Utsunomiya University, Japan

2. Introduction
When buildings change to ZEB/ZEH, the environmental loads related to construction account for a large part of the life cycle load.
The reduction of EEC becomes important.
Simple calculation method in order to evaluate EEC at design stage is proposed.

3. Outline of calculation procedure
Calculate the mass / volume of each materials / equipments by measuring drawings or quotation.
Quantity of materials x
Use EEC coefficients stored in the database.
Multiply quantity of materials by EEC coefficients.
EE & EC coefficients(intensity) +
Calculate using delivery distances for each material from manufacture gate to site.
Transport +
Site activity
Based on contractors historical data. =
EEC at construction stage
Add the above embodied impacts

4. Why simple calculation needed?
In order to reduce EEC, it is effective to estimate EEC at an early design stage.
In that time, it is difficult to get the amount of materials or equipments totally.
The EEC shall be calculated focusing on the amount of materials and equipment by pinpointing in the building where a great deal of energy consumption and CO2 emissions would occur.

5. Materials and equipment for simple calculation
The equipment and materials are total 18 items as shown in Table
Item
Name of materials and equipment
Unit
Building
Structure
Concrete
Volume (m3)
Steel bar
Weight (t)
Outer wall finishing
Tile
Area (m2) or Price
Metal window frame
Insulation
Fluorocarbon
Weight (kg)
Internal finishing
Gross floor area (m2)
Other work for building
Price or Gross floor area
Electric
Equipment
Capacity (kVA) or Price
Lighting fixtures
Quantity
Other work for electric
HVAC
Chillers
Capacity (kW) or Price
Air conditioners
Other work for HVAC
Plumbing
Plumbing work
Lift
Site work
Temporary work, electricity bill

6. Simple calculation sheet (Initial)
Item
Name of materials and equipment
Quan-tity
Unit
EE　coefficient EC
coefficient
Initial EE
Initial EC
MJ/Unit
kg-CO2/unit GJ
t-CO2
Building
Structure
Concrete A B C
D=A*B
E=A*C
Steel bars
Outer wall finishing
Tiles
Metal window frames
Insulation
Fluorocarbon gases
1,030
(R245fa) ：
Lifts
Site work
Temporary work, electricity bill
Total
18 items

7. Simple calculation sheet (Lifecycle)
Item
Name of materials and equipment
Initial EE
Initial EC
Maintenance
ratio
No. of Times Replaced
Demolition
Lifecycle　EE
Lifecycle EC GJ
t-CO2
Building
Struc-ture
Concrete D E F G H I J
Steel bars
Outer wall finish-ing
Tiles
Metal window frames
Insulation
Fluorocarbon gases ：
Lifts
Site work
Temporary work, electricity bill
Total
I=1+D*(F*years
+G+H)
18 items
J=1+E*(F*years
+G+H)

8. EEC coefficients (Intensities)
Database: 1)Process based method, 2)Input-output analysis, 3)Hybrid method.
(Depending on the user)
Fluorocarbon gas: content in the insulation material, chiller and air-conditioner.
The coefficients of site work, interior finishing work and other works are obtained according to detail calculation results of some buildings.

9. Type of fluorocarbon gas Intensity of refrigerants
Type of fluorocarbon gases and their content rates in Insulators
Thermal conductivity
W/(m·K)
Density
kg/m3
Type of fluorocarbon gas
GWP (-)
Content rate (%)
Expanded polystyrene
0.034 29
R-134a
1,430
2.7
Urethane foam (board-shaped)
0.028 30
R-245fa
1,030
4.7
Urethane foam (foamed on-site)
7.3
Emissions factor and collection rate by refrigerator
Name of Equipment
Intensity of refrigerants
[kg/kWth]
CO2 emissions factor
Recovery
efficiency
IPCC Guideline
Japan
Chillers
0.33
2%-15%
6%-7%
30%
Residential and commercial A/C
1%-10%
2%-5%

10. Sample Calculation Outline of building Building life time : 60 years
Intended use
Library
Location
Japan
Structure
Reinforced-concrete
No. of stories
3 stories
Site Area
849.37m2
Gross floor aria m2
Electrical equipment
Receiving high voltage electricity: 125kVA, Lighting and consent, Broadcast and telephone equipment, Disaster prevention system
Air-conditioning equipment
Air cooled chiller, Gas heat-pump-unit, FCU on each floor
Water supply and drainage sanitation
System for direct connection to water supply, Sanitary facilities, City gas equipment
Elevator facilities
750kg x 1 unit.

11. Result of simple calculation(Initial)
Item
Name of materials and equipment
Quantity
Unit
EE coeffi
cient
EC coeffi
Initial EE
Initial EC
MJ/unit
kg-CO2/unit GJ
t-CO2
Building
Structure
Concrete
1,729 m3
1,295
267
2,239
462
Steel bars
220 t
14100
1360
3,102
299
Outer
Wall
finishing
Tiles
4.426
106Yen
54,376
3,500
241 15
Metal window frames
13.256
35,353
2,878
469 38
Insulation
0.754
44,584
3,057 34 2
Fluorocarbon gases kg
1030
Internal finishing
2,413
m2GFA
733 59
1,769
142
Other work for building
37.437
26,500
2,100
992 79
Subtotal
8,845
1,038
Electric
Transformers
0.341
21,509
1,727 7 1
Switching boards
3.433
22,878
1,780 6
Lighting
557
Nos.
85.6
6.2 48 3
Other work for electric
16.642
441 35
575 45
HVAC
Chillers
8.440
23,502
1,808
198
Air conditioners
11.081
260 20 26
2,090 54
Other work for HVAC
24.800
657 52
1,116
Plumbing
10.965
291 23
Lifts
6.300
28,735
2,359
181
Site work
Temporary work, electricity bill
431 33
1,040 80
Total
12,047
1,342
per GFA
/m2
4.993
0.556

12. Result of simple calculation(60 years)
Item
Name of materials and equipment
Initial EE
Initial EC
Mainte-nance
Number of Times Replaced
Demoli-tion
Lifecycle　EE
Lifecycle EC GJ
t-CO2
Building
Structure
Concrete
2,239
462
Steel bars
3,102
299
Outer wall finishing
Tiles
241 15
Metal window frames
469 38 1
937 76
Insulation 34 2 67 5
Fluorocarbon gases
Internal finishing
1,769
142
5,306
427
Other work for building
992 79 3
3,968
314
Subtotal
8,845
1,038
15,861
1,599
Electric
Transformers 7
Switching boards 6
236 18
Lighting 48
286 21
Other work for electric
441 35
1,323
105
575 45
1,859
145
HVAC
Chillers
198
595 46
Air conditioners
260 20
781 60 54 2%
70%
141
Other work for HVAC
657 52
1,972
156
1,116
3,348
403
Plumbing
291 23
872 69
Lifts
181
543
Site work
Temporary work, electricity bill
1,040 80
Total
12,047
1,342
23,523
2,341
per GFA
/m2
4.993
0.556
9.748
0.970

13. Result of calculation
EE is 5GJ/m2 at initial stage, and 14 GJ/m2 at lifecycle.
EC is 600 kg-CO2 /m2 at initial stage, and kg-CO2/m2 at lifecycle.
Building work is account for large part of total emissions.
Embodied Energy
Embodied CO2
Initial
Lifecycle
Initial
Lifecycle

14. Comparison with the simple and detailed calculation method
Table shows comparison of the simple calculation method and the result of the detailed calculation.
The difference between simple calculation and detail calculation is only 4%.
The simple calculation method is good enough to evaluate EEC.
Method
Simple Calculation
Detailed Calculation MJ
kg-CO2
 Total
12,047,000
1,342,000
12,568,761
1,367,120
96%
98%
100%

15. Conclusion This study proposes a simple calculation method.
The selected equipment and materials are total 18 items only.
It is calculate that the fluorocarbon gas include in insulation material and air conditioners.
EEC calculation accuracy is relatively high.

16. Thank you for your attention