There’s an old adage “build tight, ventilate right” and evidence increasingly shows that we’re getting better when it comes to making buildings tighter, partly through progressive airtightness testing requirements. At the same time, in BSRIA’s experience of monitoring such buildings, there are often significant failures to operate mechanical ventilation systems to ensure that occupants have sufficient fresh air. There are also multiple other practical issues which conspire to affect the effectiveness of ventilation: design, construction and installation, commissioning and maintenance.
One of the unintended consequences of a supply chain not fully trained and proficient in accommodating innovation is that we can end up designing sometimes complex systems. In practice, these often don’t come close to meeting design intentions in terms of either energy or indoor air quality. By focusing on improving the airtightness of buildings, whilst not ensuring that indoor air quality is regulated or assessed effectively, we are potentially making buildings less productive and healthy than they would otherwise be.
The other issue relating to air quality that we need to bear in mind are the materials we’re putting into homes. At the moment we may not know enough about those processes. You could argue that off-gassing is going to take place over a relatively short period of time in relation to the life of a product or the building. Maybe that’s part of the commissioning process we need to look at. At one project in Canada they went to extreme lengths to strip the finishes to a very basic level. For some people that might be an acceptable choice to make but the majority of the public would probably feel it had an institutional look and feel. It wouldn’t be the kind of thing you could sell easily. It would require a very strong case for the off-gassing associated with those kinds of materials to sell it to the buying public.
When it comes to using natural materials it’s sometimes cost but it’s also risk. We need to better understand the nature of risks and occasionally take a more sensible line. Both in refurbishment and new build some of the more challenging targets are driving complexity. Because of the way the procurement and design process works, we’re not joining up all the dots at this moment in time. If we don’t join the dots correctly we’ll see more problems. If we’re going to have a growing number of systems and technologies, we need a design and procurement process that can reflect that.
One of the interesting exercises BSRIA did with the Technology Strategy Board’s Building Performance Evaluation Programme was to look at what makes a good project. You have three key components. You have a well-informed client who drives the whole process; they stay engaged, understand what they want and know how they want the building to be used. You have a design team that is knowledgeable and responsive to that and who are also creative. You have a construction team who takes care of the quality. And, to close that loop, you have the occupier who comes in and uses the building, learns and takes the time to understand what the design intent was.
In a sense a good home is about what you feel when you’re in that home. It’s about the nature of the space and how you relate to it, how well laid-out it is. If the surface appeal is there, it’s what’s beneath the surface and whether it stands up to what the occupier is looking for.
Team Leader, Sustainable Construction Group, BSRIA