Chapter 7 – Built Environment

Introduction• What is built environment?• Two strategies to consume less resources– Use less material– Use more material for higher energy efficiency in

the occupation phase• In OECD countries building use– 30 to 50% of raw materials– 25 to 45% of final energy consumption– 40% of waste to landfills

7.1.1-7.1.2

• Terms– GHGE neutral– Carbon neutral– Net zero

• Policy and codes– Efficiency ratings– LEED – not based on full LCA

7.2 Case Studies in Built Environment

• Building long-lived– What is functional unit– How has it changed

• Tradeoff between products when it is built and future energy consumption– Insulation, plastic sealing, efficiency

7.2.1 Olympic Stadium

• LCA to quantify impacts of stadium• Scope included– Procurement (raw material extraction through

delivery to building site)– Construction and change orders– Operation and maintenance for 50 years– Demolition

Life Cycle Stages Considered

• Total life cycle – functional unit was the sum of procurement, construction, operation, and demolition– Procurement of materials – functional unit materials

needed– Construction – function unit construction of stadium– Operation – functional unit was estimated events

and spectators– Demolition – functional unit demolition

Further Information on Scope

• Soft furnishings neglected• Systems outside boundary of stadium– Precinct works– Outbuildings

7.2.1.1 Results Table 7.2 (Horne et al., 2009)

Procurement Construction Operation Demolition Total

Primary energy (TJ)

137018%

1502%

600079%

801%

7600

GHGE (‘000 tonnes CO2e)

14022%

102%

47075%

51%

625

Solid wastes (‘000 tonnes)

8012%

507%

16024%

38557%

675

Water (‘000 tonnes)

68022%

903%

225074%

51%

3025

Operation a big factor

7.2.2 Building Materials

• Type of material impacts operational characteristics– Two buildings with same materials will have

different energy performance– Installation differences

• Scenarios investigated– Business as usual– More multi-residential– Reduced demolition, plus many others

7.2.2.1 - Results

Figure 7.3 Horne et al., 2009

Figure 7.4 Horne et al., 2009

Figure 7.5 Horne et al., 2009

7.3 Future Directions

• Improve thermal efficiency to reduce GHGE– Could lead to more embodied energy– Operational aspects a big part of a building

• Building rating tools partially built on LCA– Improved data– LCA can help with functional units for tools• Energy per house• Energy per resident of house• Energy per m2

7.3 Future cont.

• Appliances often not considered, but LCA could help with metrics and labeling

• LCA in urban planning– I would say roads and water– Greenspace

• LCA on an assemblage basis– 2x4 wall section