A Deep Retrofit can make a building 70 per cent more efficient and reduce CO2 emissions up to 400 tonnes a year. Retrofit Canada is starting a deep retrofit movement to make existing homes net-zero.
There are three different approaches to making your home energy efficient. And in our humble opinion net-zero ready has to be the goal. Net-zero ready means that the building can be powered by renewables like solar.
No matter what kind of retrofit you do, you should always start with an energy audit like an Energuide home evaluation to figure out your starting point. This will help you dial in the most efficient solution.
There are two main approaches to retrofits that work well:
The third option is to try to get to net-zero ready by doing the retrofit a little bit at a time. Without careful planning, getting to net-zero ready will be almost impossible and cost way more. We call this a piecemeal retrofit.
Doing a one-shot deep retrofit of your home requires planning, expertise and upfront investment. After getting an energy audit of your home, you could consider a panelized, energiesprong technique that wraps the building in pre-built walls and roof. Or you could strip the exterior right down to the studs, add some width to the walls, redo the insulation and improve weatherproofing.
Regardless of what tack you take, doing it all at once saves time and headaches.
While the price tag may be higher in the short-term, a one-shot deep retrofit that makes your home net-zero ready, more comfortable, great looking and maintenance-free will save you money in the long run.
This excerpt from a Retrofit Canada webinar describes a panelized deep retrofit:
This video is about a site-built deep retrofit where all of the construction happened on location, building new exterior walls right on the existing structure:
Sometimes it just makes sense for financial reasons or other practical considerations to plan your deep retrofit in stages. Careful planning with the ultimate goal of making the home net-zero is imperative. Costs of a staged approach may end up higher than doing it all at once, but they can be spread out over time.
You have to start with an energy audit and a plan so that all of the upgrades you do add up to a net-zero ready home.
For example, maybe you replace your roof even though that later on you will make the walls wider so they can hold more insulation or you plan to install pre-built walls on the sides. This means you need to design and build the new roof so it can accommodate the wider walls or panels. You also design the new roof to be airtight and insulated to net-zero ready r-values.
Replacing doors and windows is another good example. The window energy performance should meet net-zero ready standards based on your energy audit. They should be installed so that they can eventually tie in to new insulation, air tightness and cladding layers that needed for full net-zero ready. This takes planning.
These are just some examples of how you can make educated decisions about these investments, what order to do them, and even whether you are comfortable having to spend more money later on.
The end result is the same - a home so energy efficient it is net-zero ready.
A piecemeal retrofit is one you improve your home a little at a time with no overall plan. Maybe it starts with replacing the doors and windows. Later, you might re-insulate the walls and attic or add solar panels.
This piecemeal approach makes it very difficult if not impossible to achieve net-zero. Your home won't be airtight and its energy needs will still be higher than what renewables can provide and your money is gone.
Though the piecemeal approach might be enticing, it's a bad option for homeowners that want to be net-zero.