In this episode of Change Builders, we sat down with Deva Veylan of Coefficient Building Solutions to talk about retrofits, net zero, and what makes Vancouver Island both unique — and surprisingly well positioned — for deep energy upgrades.

Deva brings over 15 years of experience as an energy advisor, including time working in colder climates like Edmonton. His perspective bridges building science, economics, and real-world application.

And one thing became clear: retrofitting isn’t one-size-fits-all.

The First Reality: Every House Is Different

Unlike new construction — where best practices and assemblies can be standardized — retrofits are deeply situational.

Two factors heavily influence retrofit strategy:

Age of the house

• Construction practices
• Envelope details
• Insulation levels
• Air barrier continuity

Fuel source

• Electric resistance heating
• Natural gas
• Oil
• Mixed systems

Those two variables change the math significantly.

“There isn’t a universal playbook for retrofits,” Deva explains. “Each home needs a more custom approach.”

The Island Advantage: Climate Matters

Here’s where Vancouver Island becomes interesting.

Because of our mild coastal climate, it’s actually much easier to achieve significant energy reductions — even net zero — compared to colder regions.

In Edmonton, where Deva spent his early career, electrification and solar alone would not get you anywhere close to net zero in a typical 2x4 home.

On Vancouver Island?

It can.

If you:

• Electrify the home
• Install a heat pump
• Add solar panels (with BC Hydro net metering)

You can dramatically reduce — and in some cases eliminate — net annual energy use.

That doesn’t mean envelope upgrades don’t matter. It means climate gives us an economic advantage.

The Building Science Priority: Plug the Holes First

From a building envelope perspective, Deva emphasizes what he calls the “low-hanging fruit.”

Before chasing major upgrades, focus on:

• Ensuring every part of the envelope has at least some insulation
• Addressing significant air leakage points
• Fixing missing weatherstripping and obvious drafts
• Insulating uninsulated foundations or crawlspaces

He explains it simply through R-values:

• R = resistance to heat flow
• Heat follows the path of least resistance

If part of your envelope has no insulation, heat will disproportionately escape through that section — even if the rest of the house is well insulated.

It’s like plugging holes in a bucket.

Insulating a previously uninsulated basement wall can deliver more impact than upgrading an attic from R20 to R50.

The lesson? Coverage first. Optimization second.

A Real-World Case Study: Deva’s Own 1982 Home

Deva recently purchased a 1982 two-by-four home with electric baseboard heating and an uninsulated basement.

Rather than guessing at upgrades, he started with an energy audit (done by another advisor — you’re not supposed to audit your own home).

The goal: get to net zero at the lowest possible cost.

The results were revealing.

Most Impactful Upgrades:

• Airtightness improvements
• Insulating the previously uninsulated basement
• Replacing electric baseboards with a heat pump

Going from electric resistance heating to a heat pump was a massive efficiency improvement.

But here’s what surprised him.

Solar Beat Some “High-Tech” Upgrades

After envelope improvements and a heat pump, the next best return on investment?

Solar panels.

Not:

• Heat pump water heater
• Heat pump dryer

While those technologies are effective, from a pure cost-to-net-zero perspective, adding more solar capacity outperformed them in terms of financial return.

With available grants and incentives, solar became a stronger economic move than some advanced mechanical upgrades.

The takeaway: the numbers don’t always align with intuition.

Yes, Net Zero Is Possible — Without Heroic Measures

The study showed that the home could reach net zero with a 9 kW solar array — fairly large, but not extreme.

Importantly, this did not require:

• Triple-pane window replacement
• Adding insulation to the existing 2x4 walls
• Extreme or costly structural changes

On Vancouver Island, the climate makes net zero more achievable without “heroic” envelope interventions.

In Edmonton? The same house wouldn’t come close.

The $40,000 Interest-Free Loan: An Economic Lever

One of the most powerful tools in the retrofit space right now is the $40,000 interest-free Greener Homes loan.

Deva breaks it down simply:

If:

• The payback period of your upgrade is under 10 years
• And you finance it with a 10-year interest-free loan
• Then the upgrade can be cash-positive immediately.

In other words:

• The energy savings can exceed the loan payment
• After 10 years, the savings are fully yours
• That changes the economic equation entirely.

While not every house can reach net zero for $40,000, the loan significantly lowers the barrier — especially for electrification and solar.

“It becomes almost a no-brainer in some cases,” Deva says.

The technology exists. The expertise exists.

At this point, the biggest question isn’t technical.

It’s economic.

The Big Picture: It’s an Economics Problem Now

Deva’s final point is a powerful one.

From a technical standpoint, we can make almost any house net zero.

We have:

• The modeling tools
• The heat pumps
• The solar technology
• The building science knowledge

What determines feasibility is economics — not physics.

And on Vancouver Island, the combination of:

• Mild climate
• Net metering
• Electrification
• Interest-free financing

Makes the math more compelling than many homeowners realize.

What’s Next?

Deva is documenting his retrofit journey, collecting real-time energy data with monitoring systems, and plans to publish a detailed white paper in the coming years.

The goal: turn real-world retrofits into education tools for homeowners and industry alike.

Because if there’s one message from this conversation, it’s this:

Retrofitting isn’t about doing everything.

It’s about doing the right things — in the right order — for your specific house.

And on Vancouver Island, we may be better positioned than we think.