SUTD-MIT INTERNATIONAL DESIGN CENTRE (IDC)
Grand Challenge: Sustainable Built Environment
Markus Matthias Hudert
Amanda Ng Qi Boon
Lynette Cheah, ESD/SUTD
Colin Yip, Arup Singapore
Richard De Neufville
The workflow will be specifically catered to hybrid construction systems, e.g. the combination of reinforced concrete and mass-engineered timber.
Two initial studies were carried out to evaluate improvements achievable by increasing the use of timber as a construction material in Southeast Asia, a region of massive urban construction in close proximity to vast resources of timber as a renewable and sustainable, but regionally still rarely applied construction material.
The focus is on the structural elements. For both studies, the LCA system boundary is set to cradle-to-gate, assessing the the Global Warming Potential (GWP) of different construction variants of a notional case-study building. The results of these two studies will also serve as benchmark for results obtained with the software tool, once it is fully operational
The first preliminary study used the Athena Impact Estimator for Buildings for a comparative evaluation of different construction system and material application of an entire building wing. The findings were presented at the Future Habitation Symposium at the National Design Centre in Singapore.
From left to right: full concrete shear wall building, Cree inspired solution, hybrid variant with CLT floor and wall elements.
With 547,000 kg CO2 eq, the full concrete shear wall building had the highest GWP, confirming earlier assumptions. The result for the Cree inspired solution was 349,000 kg CO2 eq. The hybrid variant with CLT floor and wall elements resulted in 283,000 kg CO2 eq.
Full concrete shear wall building: 547,000 kg CO2 eq, highest GWP
Cree inspired solution: 349,000 kg CO2 eq., (reduction of 36.2 %)
Hybrid shear wall system variant with CLT floor and wall elements: 283,000 kg CO2 eq., (reduction of 48.26 %)
For the second study, a spreadsheet-based Life Cycle Inventory (LCI) was established based on the Quartz Common Product Database. It uses more detailed geometrical models, based on a preliminary dimensioning of the structural members. The study only compares the material quantities of a unit corresponding to a nuclear family apartment. The calculation of the GWP is carried out within a Grasshopper™ definition, set up by the authors. The detailed findings will be presented at the IASS Annual Symposium 2019.
Back, left: Full concrete system, right: CLT concrete hybrid system
Front, left: Cree inspired, right PPVC hybrid system
The full concrete shear wall system remains the system with the highest environmental impact of 94,118 kg CO2 eq. The Cree inspired solution and the hybrid shear wall systems have significantly lower results:
Full concrete system: 94,118 kg CO2 eq
CLT concrete hybrid system: 56,036 kg CO2 eq (59.5 %)
Cree inspired 33,371 kg CO2 eq (35.5 %)
PPVC hybrid system: 40,060 kg CO2 eq (57.4%)