As part of a study to investigate the condensation risks for buildings in different climate zones across Australia, the ABCB is seeking a Service Provider to develop a testing regime and conduct physical testing on construction systems commonly found in tropical and sub-tropical climate zones. The study will analyse the risks of condensation in typical external wall systems used for compliance with the energy efficiency requirements of the National Construction Code (NCC). This will include wall systems compliant via the Nationwide House Energy Rating Scheme (NatHERS) at a 7-star level and the Deemed-to-Satisfy elemental provisions to identify wall systems most susceptible to condensation within the built system in a given climate region. The study will also investigate design principles to mitigate condensation in external walls.

The work will be delivered in two phases. Phase One will entail a literature review of existing relevant materials and research covering:

• condensation risks in NCC compliant residential buildings
• literature and analyse international case studies, focussing on successful and failed mitigation strategies
• results from hygrothermal simulations undertaken by the ABCB to date
• key environmental factors (e.g. humidity) and components (e.g. insulation, ventilation, thermal bridging and the like) which influence vapour flow across external walls
• wall systems, their respective components and relevant indoor and outdoor climatic conditions to be simulated experimentally

Phase One will also provide designs for test rig(s) and develop a comprehensive testing methodology to simulate typical environmental factors experienced by buildings representative in tropical and sub-tropical climate zones. Note, multiple test rigs may have to be designed depending on the type of construction systems being investigated and its scale.

Phase 2 involves construction of the test rig(s) and testing using methodology described in Phase 1. As a minimum, temperature, humidity, and air flow are to be generated and monitored across various parts of the built system. Continuous video recording may also be used to log the occurrence of condensation. Fees should be provided as an indicative fixed lump sum for this work. The supplier should provide an associated proposed scope of work which may be taken up by the ABCB as a variation.