Deep Retrofit Slashes Energy Use 68% in 110-Year-Old Ottawa Home

The owner of a 110-year-old house in Ottawa South is enjoying significantly lower power bills after deep energy retrofits slashed his home energy requirements 68%, eliminated drafts and dampness, and guaranteed him comfortable indoor temperatures—come winter or summer.

Denis Dumas knew an energy upgrade was “in the cards” when he bought his charming but terribly energy-inefficient home in 2006, writes Ottawa’s EnviroCentre. It came with high energy bills as well as natural gas heat, a feature that Dumas immediately knew he wanted to change.

“Considering what is happening to the environment, with climate change, any part you can do to reduce your emissions is a step in the right direction,” Dumas said.

His “retrofit journey” began nearly 14 years ago in 2009, when he booked an EnviroCentre home energy assessment. A registered energy advisor supplied him with the information he needed to get started on the path to a fully electric, energy-efficient, comfortable home.

First, he concentrated on the very leaky building envelope, which made the property damp and drafty. Contractors insulated the exterior walls with blown cellulose, installed energy-efficient windows and doors, and replaced a moisture-grabbing basement slab floor with one that had hydronic heating built in.

That last change was made possible by the geothermal heat pump Dumas installed, knowing that he wanted to go fully electric. “The only way to go forward is to electrify everything,” he said. “Eventually, power generation will be non-polluting, and we will be much better off to cut emissions completely.”

EnviroCentre writes that the upgrades reduced the total energy required to heat and cool the house by 68.3% and lowered onsite emissions to zero, from roughly 11.01 tonnes of carbon dioxide equivalent.