Platform-floored residential construction and reflective subfloor insulation

The adoption of increased thermal performance require-ments, as specified in the National Construction Code, has over time been linked to a significant reduction in the use of timber products. In-ternational design and construction research and practice suggests that an assortment of construction methods may be adopted to improve the insulation and thermal mass properties of lightweight buildings. Tim-ber and lightweight construction need to be thought of as complemen-tary to, and intrinsically linked to, improved and/or high thermal per-formance buildings. The thermal performance Test Cells at the University of Tasmania are being modified progressively and used as a testing platform for a range of lightweight building systems. The current iterations include reflective subfloor insulation, bulk subfloor insulation for insulation, and mass-timber for thermal capacitance. The testing regime includes unconditioned, intermittently conditioned and permanently conditioned modes of operation. This paper focuses on the first stage of the current research program, namely the use of reflective subfloor insulation in traditional enclosed-perimeter plat-form-floored residential construction. This research has utilised two types of installation, namely, installation by industry to accord with industry common practice, and installation by industry to manufactur-er’s specification. This process has shown significant shortcomings in product literature, technical advice and installation practice likely to result in lower than predicted thermal performance.