Good thermal bones
There’s a classic little ex-govie house in Watson with some very special touches, and extremely good bones, on the market right now.
It’s a great example of what to look for, or what to consider when comparing homes for sale or rent. Not all houses are created equal. That lack of equality can have serious financial and physical impacts, particularly in a climate as extreme as Canberra’s. We do not live in a mild climate like that of the NSW central coast or Brisbane — this stuff is really important in climates that need significant winter heating AND that can also get stinking hot in summer.
Having lived in many different homes in various climates, and worked on hundreds of others in Canberra, I’ve experienced first-hand, and second-hand, just how much homes can impact people’s health, comfort and happiness… and therefore energy and medical bills.
Living in highly temperature-unstable housing is, quite simply: BAD for us - physically, mentally, financially. That’s why I am so passionate about retrofitting houses to make them more energy efficient and climate resilient.
Ceiling Insulation
On the 12th of February, a 28 degree day preceded by a week of days between the high twenties to mid-thirties, I visited the home and did some thermal imaging which confirmed that the newly installed R5 insulation had been laid very thoroughly and evenly. See the images below (typically we find gaps, and lifted batts).
The ever so slightly warmer, but still super comfy ceiling surface temperatures (first three shots), were recorded in the rooms facing NE (living area and main bedroom) that were being struck by the morning sun at the time of imaging. The next two ceiling thermal images are from the north western kitchen and the south western bathroom. The last two images show, as we would expect, that the walls of the home would benefit from wall insulation which is a pretty simple and cost-effective retrofit job which a few companies in Canberra can do.
NOTE: we also air leakage tested the house but I’m going to save you from my excitement about draughts and draught sealing, other than to say the remaining ones are super easy to fix and the new owners can contact us for a quick summary of where they are and how to fix them. All quick and easy with big bang for buck wins for comfort and efficiency.
Heating and Cooling
Now this next bit may cause some of you to glaze over or want to bury your head in insulation. For those who are not science nerds and may not like numbers and graphs so much, I’ll cut to the chase with a short, sweet summary (and the data nerds among you can enjoy the supporting screen shots below).
This home currently has an EER of 3.6 stars - that’s much better than a lot of Canberra homes, thanks to its excellent orientation. It is currently predicted to require quite a lot of energy for heating over winter and a fair bit for cooling over summer. Afterall our climate is pretty harsh.
With the simple, cost-effective retrofit measures of insulation to the walls and floors (plus some draught sealing) it can get all the way to 5.5 stars.. That equates to a massive 58% reduction in the energy needed to maintain the home at comfortable temperatures across a Canberra winter (not a mild Sydney winter but our harsh, potentially -8 July days).After doing these most cost-effective (less sexy) measures first, you’ll already be saving money and feeling loads more comfy. Then… you might choose to install good double glazed windows. After saving up and installing good windows, the rating jumps to 7.5 stars and the predicted total annual energy use for heating and cooling plummets by a whopping 71%.
NOTE: There are some incentives from government and various financial institutions to help people fund efficiency upgrades.
These calculation are based on thermal performance modelling of the home using the Nationwide House Energy Rating Scheme software HERO. The Powerhaus App has then been used over the top.
Monthly Net Zero
For you energy geek gluttons, now let’s talk about the house being all-electric with efficient RCAC split systems for heating and cooling, heat pump hot water and having a 5kW solar system on the roof.
Assuming we have four residents in the home, it is predicted that this house could be net zero, in fact energy positive, 8 months of the year as it currently is… AND energy positive EVERY month of the year after making the other insulation, draught sealing and glazing uprades.
You often hear people talking about homes with solar panels being energy positive. They mean ANNUALLY. That’s actually super easy. Pretty much every Light House with more than a 1.5kW PV system is easily energy positive across a year. However, that does not mean that the home does not consume more energy than it generates in the depths of winter. That’s the big goal — to use less than you generate in the middle of the year. This house could. We know it is possible - we have three or four Light Houses that do this. This means you’ll have excess energy to charge an electric car too!
Good luck everyone… or rather, good luck and good science!
I do know that options are limited and not everyone will be able to jag a goodie like this. Even if you can’t find the best thermal bones, don’t give up, there are ways to improve the efficiency and your comfort of the house you live in. I’ve lived in south and west facing houses… my kids are doing the rental shuffle. I see you. That’s why my friend Lish Fejer and I started FixItChicks.
Declaration of a friendly conflict of interest
I have no financial link to the sale of this home but happily declare that I am friends of both the owners (professional energy efficiency colleagues) and the agent (who lives in a Light House). These people all get sustainable housing and how comfortable Canberra homes can be with a bit of science in the mix.
I have not been paid (nor even been asked) to prepare this blog. I’m just a passionate energy geek who wants to get these tips out to a wider audience at any opportunity. I have three adult kids — I know how bloody hard it is to find decent housing.