This study compares the life cycle environmental impacts of two multilevel residential buildings built in Melbourne, Australia. The study was commissioned by Australand and funded by Forest and Wood Products Australia (FWPA).
The first building considered, the ‘Study Building’, incorporated an innovative light weight building approach utilising a stick-built timber frame and a ‘cassette floor’ building system. The second building, the ‘Reference Building’ utilised a more typical building approach, incorporating precast concrete panels and suspended concrete slab floors (Table 1).
The primary goal of the study was to compare the potential environmental impacts of the above buildings across their respective life cycles.
The study employed the LCA methodology described by the ISO14044 standard to undertake the comparison of the buildings. The analysis addressed a building life cycle scope which was prescribed by GBCA (GBCA 2014), which in turn based the boundary definition on the EN15978 standard, as shown in Figure 1. Although EN15978 was used to define the scope of the LCA, the study is not intended to be fully compliant with the standard.
This project developed Cost Plans for the structure of four building types; a 7 storey office building, an 8 storey apartment building, a 2 storey aged care facility and a single storey industrial shed. Each solution was designed and then independently costed for a timber option as well as a more conventional concrete framed or steel framed solution for a reference location in suburban Sydney. The site was assumed to have no significant cost implications concerning site access, ground conditions or neighbouring properties. The investigations considered only the elements of the building for which there were significant difference and ignored the cost of elements that were the same.
The timber structural solutions were found in all cases to be significantly less than the competing non-timber solution. The cost of each of the main components were found to be significantly cheaper in timber for each building.
The next best opportunity for the timber industry is the office and institutional building markets as both building forms are similar. This report shows that this market segment has great potential as this building design showed the significant cost savings particularly if a decorative ceiling is omitted.
Lend Lease is constructing a new residential building using cross laminated timber (CLT). This
material is a relatively new building material in Australia, which has found increased use in multi-story residential and commercial buildings, particularly in Europe. The Centre for Design (CfD), School of Architecture and Design, RMIT University was commissioned by Lend Lease through Forest and Wood Products Australia (FWPA), to investigate the environmental performance associated with the production of the materials, along with HVAC and lighting systems, and associated operation and end-of-life of this novel building, using a life cycle approach.
Life Cycle Assessment (LCA) has been used as the core method for determining the potential
environmental impacts of the products considered. LCA has been applied in accordance with ISO
14040:2006. Data on the building materials quantities and construction details were supplied by Lend Lease, background life cycle inventory data was gathered from Australian (AUPLCI) and European (Ecoinvent) databases. Data on cross laminated timber was provided by the manufacturer in an Environmental Product Declaration (EPD). Annual operational energy use for the Forté and the reference buildings were calculated using the dynamic building energy simulation software tool ApacheSim. The simulation results for residential spaces were validated against results from an Accurate assessment.
This report was commissioned to review and formulate strategies for the accelerated uptake and
social acceptance of living in multi-storey cross-laminated timber (CLT)-constructed buildings in infill developments to: remove cultural barriers, meet the sustainability expectations of potential buyers and obtain a better understanding of how we can facilitate the rapid introduction of this innovative construction technology in Australia.
An extensive review of literature within the field was conducted to gather an overview of the
barriers that inhibit consumers, governments and industry in the uptake and acceptance of CLTconstructed buildings for infill development. Data was collected on CLT buildings worldwide, to build a comprehensive picture of multi-storey timber buildings using CLT-construction systems.