**6. Conclusions**

Both these projects clearly illustrate the challenges for sustainable energy futures that can arise if environmental strategies are not successful. Both of these projects have produced low energy buildings, of high architectural quality, but these studies have identified that un‐ less environmental strategies are carefully designed, implemented and maintained, unin‐ tended negative consequences can arise. As well as producing potentiall harmful environments which can have detrimental effects of occupants health, poor ventilation de‐ sign can undermine strategies for energy conservation as occupants attempt to achieve com‐ fort by conventional means such as window opening.

In both projects the role of building users is two-fold – as operators and as consumers. In the former role, building users have a part to play in ensuring the efficient and effective per‐ formance of the buildings, but this role is significantly moderated by their environmental experience, the effectiveness of the systems and their control over them. Thus a system that cannot effectively control comfort leads to behaviours that can increase energy consump‐ tion. In the latter role, building users are subject to the environmental conditions of the buildings and may experience discomfort or even detrimental health effects if the environ‐ mental strategies are ineffective.

The results and discussions from both projects conclude that the design of mechanical venti‐ lation heat recovery systems does require further consideration in order to provide healthy levels of IAQ in both projects whilst maintaining good energy efficiency. In the Glasgow House the considerable improvement in CO2levels between the study periods indicates that the design itself is reasonably good, however, there is still need for improvements within the bedroom areas and poor IAQ was still experienced. Remedial measures are also proposed in Gilmores Close and it is hoped that there will be an opportunity to monitor the results of this. The projects also illustrate the need for holistic environmental design, which takes into account a range of design requirements, including obvious environmental factors such as heating, ventilation, lighting, and controls, but also relating these to other design parameters such as the nature of occupants, maintenance and fire safety.

The studies also illustrate the value of information revealed by the use of BPE. Underper‐ forming systems which potentially endangers the health of the occupants will not be appa‐ rent unless the buildings are evaluated in use. Without these studies the conditions in these dwellings would not be known, nor would the knowledge about the issues and how they may be addressed be revealed to the industry in general. In the current low carbon environ‐ ment most new buildings are experiments – it is vital that we go back and check the results. Collectively, the design, installation, maintenance and the need for BPE require further con‐ sideration in order to provide exemplary indoor air quality in Scotland's future housing stock.
