Why the Coolest Homes Aren't Green

We caught up with Bryn Davidson, Principal Designer at Lanefab, a Vancouver-based custom home building company, about his TEDx talk. If you haven't seen it, this is a TED talk EVERY homeowner and building pro should watch.

What's the problem with some of the current thinking when it comes to sustainable building?

The problem, as I see it, is that too often our conversations are just about the building and not about the overall project. The project includes more than just the building itself; it also includes the important decisions about where you choose to build, and what your building is replacing. If your goal is to simply create a nice building or to be self-sufficient, or off-grid, then its fine to just focus on doing Net-Zero or Passivhaus or whatever building target you want to meet. If, however, your goal is to contribute something positive in the fight against climate change, the location and site history can't be ignored.

As an example, if you're living in a draughty old house in town, you might think that building a Passivhaus in the country - on a beautiful open site with good sun access - might help you lower your carbon footprint. If you only look at the building, then - yes - this is true. If you look at the project, however, you'd see that you're now having to drive twice as much as when you lived in town and that your driving emissions are wiping out the benefit of the green building.

As another example, say you're trying to decide between two different lots to build on, one that's a greenfield, and one that has an old house on it. It's tempting to build on the open site, but - from a climate point of view - it would be much better if your construction dollars took away the GHGs (Green House Gas) being emitted by the old building. The choice to renovate, or replace, an old building is a big part of the overall story about how your project impacts the climate.

For this reason, I think that our goal should be to build "Net Positive". This simply means that there are fewer GHG emissions going into the air after your project is done. It's a simple idea but it requires a real shift in thinking. Net-zero, Passivhaus, etc. are all fantastic tools, but they need to be plugged into the goal of achieving Net-Positive.

In our own work, we are constantly fighting against the challenges of doing green homes in a dense urban context. There are myriad rules and costs and delays, but - at the end of the day - we feel good that we're doing green infill in walkable neighborhoods.

What's a Net Positive Home?

A net-positive home is one where you've asked the key questions: how good is the building, where is it located, what does it replace? If it's a good green building that replaces an older home, in a walkable location, there is a good chance it's a net positive project.

In New York, there are a lot of interesting net-positive projects happening including passive house renovations to existing row houses and even a passive house high rise. In the case of the high rise, the building will use more energy than what it replaced, but it will get a credit for reducing the transportation needs of every person living there.

If you're not in Vancouver, or New York, or another highly walkable area, it is still possible to build net positive; you just need to find an old building that is emitting tons of GHGs and replace it with your new green home. I understand that much of North America is very suburban and rural and that not everyone can choose their location, but we can pick to build on a 'grayfield' site instead of a 'greenfield'.

What do you think people need to consider the most when thinking about building/renovating their homes?

It depends on your goals. Most people aren't trying to be climate leaders in their day to day life, but it's not too hard to align concerns about quality and comfort with concerns about the climate.

In general, though, I encourage people to build smaller, but better. For the same cost as a big inefficient house, you can usually have a better designed and better built compact home.

What would you tell homeowners who are budget-conscious and still want to be able to build this way?

There are a variety of ways that you can do a Net-Positive project, and it doesn't require tons of money or all sorts of 'green bling'; you can simply move to a more walkable neighborhood or you can do a renovation to an existing building. If you can pick a location where the Walkscore is higher than the regional average, then you know you're having a positive impact. If you add insulation to an old house, then the project is Net-Positive.

If you are in a position to build a new home, and you are financing the construction, the amount that you add to your mortgage payment each month to 'go green' can be offset by your savings in energy cost. You can be saving money on your cash-flow from day one, while also getting a home that is higher quality and more comfortable.