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Client Mission and Review:

If the never-ending battle with mold and mildew on our spongy wooden window trim (even some tiny mushrooms at one point?) wasn’t enough, the winter breeze tickling the back of our necks while trying to relax on the couch convinced us – it was time to address the blaring energy efficiency and comfort/health deficiencies in our Dartmouth 1950s bungalow.

We knew replacing the windows would offer some improvement, but accepted the reality that it was better to address the building envelope in general to achieve a far superior result in terms of comfort and performance. Previous home improvement projects had shown us that our walls were poorly insulated with a mix of dried-up seaweed in some areas and mildew covered fiberglass batts in others, and lots of gaping holes throughout. Kestrel helped us come up with a plan to replace our drafty old windows with new high performance triple glazed windows, but also add a layer of exterior insulation and a tight air barrier. This in turn required new siding, and although we had grown to love our yellow shakes, they too were on their last legs. May as well update our crumbling, uneven concrete front steps while we’re at it! So, there we were with a full exterior remodel ahead of us, but with plans to eventually finish our basement we decided it would make sense to also replace our oil furnace with a centrally ducted heat pump and HRV at the same time. Did I mention the non-negotiable completion of all of this in time for our backyard wedding in July?

Completing these projects at the same time had a few benefits. Foremost – it would be done. We had grown accustomed to living in a construction zone in some part of the house more or less since moving in, but decided reno-chic wasn’t the look we wanted for our wedding. Second – it only really makes sense to upgrade an air barrier all at once, and with a much tighter envelope our house would need some help with air circulation from the new heat pump and HRV. Finally, completing multiple energy efficiency upgrades together allowed us to take advantage of the $40,000 interest free loan through the Canada Greener Homes program, as well as qualifying for about $8500 in combined federal and provincial rebates. Together these upgrades were a huge step towards our long-term goal of living in a net-zero home.

The material selection and planning prior to construction allowed a quick turnaround, and the results have been amazing. Our house is far less humid, significantly quieter, the temperature is far more uniform throughout the house (no more cold spots near windows, doors, or corners), and as we enter our first heating season, we are expecting significant savings on our heating costs.

As with most home improvement projects, we ended up tackling quite a bit more than initially planned, but we are so happy we did. Kestrel helped us see the benefit of addressing multiple systems from mechanical and insulation to windows and cladding in order to get the result we were really after, which was a high performance energy efficient home with huge improvements to interior comfort.

Products used:

Windows: Kohltech Select triple glazed

Doors: Kohltech Cellular PVC with triple glazed lites

Insulation & Air Barrier: Zip-R Sheathing panels (R9.6) with taped and/or liquid flashed seams & terminations.

Siding: Spruce shiplap treated with Lifetime wood preservative.

Rainscreen: Coravent Sturdi-batten and SV3 insect screen

The Kestrel Process:

There are a lot of complicated considerations when embarking on a construction project as you can see from Dante and Carolines project outline. Ultimately though if budget allows this is the route that we’d like clients to take. Although a new kitchen/finished basement was also on the wish list, these guys were not leaving the house anytime soon, and recognized they could deal with those wish list items after the comfort factor had been addressed.

Like many older bungalows in Dartmouth, their home was quite dated, aesthetically and from a performance standpoint. Although it had something going for it that many larger homes don’t, which is what we call the bungalow factor.

The bungalow is an ideal home for a light passive energy retrofit due to its architectural characteristics and layout. With its single-story design and compact footprint, the bungalow offers excellent thermal efficiency potential. Implementing energy-efficient measures such as improved insulation, air sealing, and energy-efficient windows can greatly enhance the building's thermal performance. The bungalow's relatively small size also makes it easier to achieve airtightness, reducing heat loss and improving energy efficiency. Furthermore, the layout of the bungalow, typically with open floor plans and fewer internal walls, allows for natural light to penetrate deeper into the living spaces, reducing the need for artificial lighting during the day. These retrofit strategies can transform the bungalow into a comfortable and energy-efficient home, reducing energy consumption and environmental impact while providing a sustainable living space for its occupants.

Not all buildings have it this easy, and therefore it doesn’t always make sense financially.

Timing was tight for this project due to a backyard wedding that was quickly approaching, so we had to hit the performance levels we were looking for, and do it efficiently.

For the exterior portion this involved stripping the old cedar shingles and removing the old leaking windows. We followed this up by wrapping the entire house in a 3 in 1 WRB known as ZIP. Our specific product was 1 ½” of Polyiso laminated to the back of ½’ OSB, with an integrated WRB on top. What you end up with is a 2” thick 4’x8’ panel that you can nail onto the existing house very quickly. On top of this we inserted new Koltech Select Triple glazed units and taped all seams to create a new primary air barrier. This also enhances the effectiveness of the existing 2x4 cavity insulation by wrapping an insulated jacket around it. Although we have only upgrade to what is essentially an R20 in the walls, the air sealing upgrades, exterior insulation, and triple glazed window units put this wall assembly on par/a little better than a current code built 2x6 assembly. Which, for a 1950’s bungalow is quite the improvement.

Once this process was completed we were able to clad it with a vertical shiplap siding which went on extremely fast and offered a more contemporary look. Paired with a rainscreen detail using Coravent’s Sturdi Battens, it’s an assembly we feel is a real winner! After this was all completed they were able to remove the old inefficient oil furnace, and replace it with a new centrally ducted heat pump, and tie in a new HRV.

We’ll try and update this as we make it through the upcoming winter season here, but initial observations have shown a huge improvement in building efficiency and comfort levels, particularly sound levels in the busy neighborhood. This comfort We find is the real selling point for our clients, especially when they’re in a busier traffic area.