Background

Scotland’s Housing Expo was held in August 2010 in Milton of Leys, Inverness. It was a high pro le event developed to showcase innovative sustainable housing with a variety of design ideas and technologies contained on one site. The event was the rst of its kind in Scotland and was based upon similar Expo models found in mainland Europe and the Nordic countries.

All dwellings on the site were architect designed and delivered under a unique design and build arrangement by five developers working together on site in partnership with the local housing agency the Highland Housing Alliance (HHA). The project was completed in 2010 and comprises 56 individually designed low energy homes.

The Building Performance Evaluation (BPE)

The BPE study was undertaken from August 2012 – October 2014 and the nal report submitted to the funding body TSB (now Innovate UK) in December 2014 and approved by them in February 2015.

The study focussed on eight dwellings: four of these were social rented homes and four were owner occupied, sold under a shared ownership scheme. The dwellings selected for study were from four different plots (two dwellings on each plot) each having particular features and design approaches of interest to the construction sector. The comparison of two dwellings from each plot allowed analysis of the effects of occupancy in identically constructed dwellings as well as, a comparison of performance across the differing dwelling designs.

The study examined the relationships between design intentions and predictions, impacts of the procurement process, users’ experiences and perceptions of the design, and metered environmental and energy performance. Occupant engagement, in the form of diaries, and the testing of improved occupant guidance were included as part of the project.

The study is now complete and the findings are set out in the summary report attached below.

The main findings were that:

• well sealed buildings without whole house ventilation units result in unacceptably high CO2 levels especially overnight when windows are less likely to be opened and in situations where people dry clothing indoors. In addition, air quality was generally poor in terms of high moisture levels.
• Trickle vents are not adequate to compensate for inadequate ventilation.
• Under-heating was not an issue due to high levels of insulation – but this was counterbalanced by the fact that most of the houses had unnecessarily
  especially overnight when windows are less likely to be opened and in situations where people dry clothing indoors. In addition, air quality was generally poor in terms of high moisture levels.
• Trickle vents are not adequate to compensate for inadequate ventilation.
• Under-heating was not an issue due to high levels of insulation – but this was counterbalanced by the fact that most of the houses had unnecessarily