By Matt Root
The details of better building are well understood, but when considering the variety of options it’s all too easy to get tangled with needless complication. Yes, parametric energy models provide cool visuals, but since we already know the basics, let’s take a look at some ways to increase performance and keep it simple.
Well-established strategies and ambitious but achievable metrics provide us with some key starting points. Every project and each project team is different, and we all know the devil is in, well, the details.
Here are ten easy steps, and we note that there is flexibility in all of them:
- Make it airtight: 0.10-0.15 cfm75/sq ft shell area
- Detail continuous exterior insulation:
- Aim for a true R15-20ish in the walls
- Small things can make a difference—such as using thermally broken attachment clips
- Ensure that there are no major structural thermal bridges
- Stick to a modest window to wall ratio—24%ish is good
- Look at higher performance windows
- You don’t necessarily have to go to triple glazed, but doing so may allow higher window to wall ratios
- Employ high efficiency air source heat pumps for heating and cooling
- Air to water heat pumps are also worth a look
- Specify 85%+ high efficiency ERVs
- For residential units, ensure that fresh air is routed directly to each bedroom (as opposed to the return side of the fan coils)
- Minimize ductwork on roof
- Minimize the DHW loads
- Location, location, location—and simple here means establishing the best possible building orientation for solar
- Design for unit compartmentalization (0.30 cfm50/sqft)
- Whole-building sealing is essential, but don’t overlook sealing up gaps between adjacent residential units
Of course every step won’t be applicable or achievable in all cases, but giving each of these basic ideas due consideration at the outset covers the essential factors for a high performance building. When we begin a project by getting clear on the goals and appropriate standards such as these, we provide valuable parameters—creating a solid framework that the design and construction teams can leverage to perform their finest work.
