Janice Foster

An assessment of environmental conditions in bedrooms of contemporary low energy houses in Scotland

This paper describes the monitored environmental conditions in the bedrooms of 26 low energy houses in Scotland, include both naturally ventilation and houses with mechanical ventilation with heat recovery systems (MVHR). The context of the paper is the performance gap that is emerging between design predictions and actual performance of housing, and this paper focuses on the environmental performance of bedrooms. Bedrooms are of particular interest as they are the spaces in which occupants have the greatest exposure to the indoor environment, and in which conditions are relatively constant. The study indicates that ventilation is generally poor in these spaces and that both temperature and humidity frequently exceed accepted parameters for comfort and health. Increased window opening is a mitigating factor, but effects are limited by overall ventilation strategies.

Overheating in Scotland: contributing factors in occupied homes

ABSTRACT There is growing awareness of the overheating risks in new-build properties in the UK. However, this tends to be considered a problem principally for the southern regions in the UK, only becoming a serious issue in the north of England in the medium-term and in the long-term for Scotland. This notion tends to be largely predicated upon climate change predictions, differences in latitude and summer air temperatures. This paper describes the results from Building Performance Evaluation (BPE) studies over a two-year period from 26 occupied new-build homes across Scotland which demonstrated incidences of overheating. Results suggest that low-energy buildings are susceptible to overheating despite northerly latitudes, with 54% of houses studied overheating for more than six months annually, and 27% of homes overheating for less than 10% of the year. Evidence indicated that commonly used prediction tools do not appear to anticipate overheating adequately. This paper maps common overheating causes due to design and the role of occupants, identifying the risks due to the regulatory system, prediction and procurement processes, and design and construction. A common finding was that design and occupancy factors appear to have a greater impact on overheating more than location and climatic factors.

Comparative Performance of BAPV Systems in Scotland: 4 Case Studies with Differing Energy Contexts

The paper compares the performances of four building-added photovoltaic (BAPV) systems, one located in a North-East maritime location, one in a North-West maritime location and two in East Central Scotland. Each BAPV system will be described within the overall energy context of its host building, all with varying functions – a refurbished further education campus, a new-build community centre, bespoke new offices and an existing factory and company headquarters. The last two are concerned with solar branding, while the first two place BAPV discreetly within a wider energy strategy that exploits solar energy thermally by various means, some less directly than others. The paper confirms respectable outputs from each of the PV arrays, ranging from 705 to almost 900 kWh/kWp, but with varying output significance, partly due to PV array area and configuration range from 72 to 647 m2, relative to the overall energy demand.