Industry & Code
What BC Energy Step Code Step 5 Actually Means for a Burnaby Custom Home
Step 5 isn't a sticker. It's a measurable airtightness target that changes how a Burnaby custom home gets framed, sheathed, sealed, and ventilated — here's what it actually requires.
When a Burnaby homeowner asks us about Step 5, they almost always mean: is my new home going to be built to it? The short answer depends on your municipality — but if you're building in Burnaby, yes, Step 5 is the current minimum for new single-family construction. The more useful answer is to explain what Step 5 actually requires of a builder, because the requirements quietly reshape five or six trades' work, not just the energy advisor's spreadsheet.
This post is for the homeowner who wants to understand what Step 5 means for the framing, the sheathing, the windows, the ventilation, and the way a custom home actually behaves once you're living in it.
What Step Code is, and what Step 5 isn't
The BC Energy Step Code is a performance standard added to the BC Building Code in 2017. It replaces the old prescriptive "build it this way" requirements with a measured outcome: the house must perform this well. The performance is verified through energy modelling and a blower-door airtightness test. There are five steps for Part 9 residential, with Step 5 the most stringent.
Step 5 is not "Net Zero." It is not Passive House. It does not require any specific equipment. It requires that the house, as built, hits a numerical target: a Mechanical Energy Use Intensity (MEUI) and Thermal Energy Demand Intensity (TEDI) below the published Step 5 limits, with airtightness measured at no more than 1.0 air changes per hour at 50 pascals (ACH50). How you get there is up to the design team.
The provincial baseline since January 1, 2025 is Step 3 with a Zero Carbon Step Code Emissions Level of EL-4, overlaid for all new Part 9 residential in BC. That's the floor — it's the minimum you must hit to get a building permit anywhere in the province. But many municipalities have adopted higher local requirements. Burnaby requires Step 5 for new single-family custom homes, as do Vancouver, West Vancouver, Coquitlam, and several other Greater Vancouver municipalities. If you're building in Burnaby, Step 3 is not enough to pass permit — you need Step 5.
Step 5 is not a finish — it's a way of building. By the time you're choosing tile, the decisions that made Step 5 possible were already made.
— Sanj Aggarwal, CHBA BC Master Residential Builder
The airtightness target — 1.0 ACH50
This is the single number that matters most to construction quality. The standard pre-Step Code home tested somewhere between 3.5 and 7 ACH50. Step 3 demands 3.0. Step 5 demands 1.0 or better. Hitting 1.0 is not done with a single product; it's done through a continuous air-control layer detailed across the entire envelope, with every penetration — vent, conduit, wire — sealed.
In framing, this means we're using a designated air barrier (often the exterior sheathing taped at every joint, or a fluid-applied membrane) and we're treating every transition between assemblies — wall-to-roof, wall-to-window, wall-to-foundation — as a sealing detail to be drawn and inspected. Drywall as the air barrier is a strategy of last resort.
The blower-door test happens once before insulation and finishes go in (so leaks can still be repaired) and once at completion. We've watched well-intentioned framing crews deliver 2.4 ACH50 on the rough test. The remediation between rough and final isn't free, and it's why we now pre-brief the framing crew on the air-barrier strategy at the design coordination meeting, not when the wall is up.
Envelope decisions that get you to Step 5
A Step 5 wall in the BC south coast climate is most commonly built one of three ways:
- 2x6 framing with continuous exterior insulation. The structural cavity is filled with batt or dense-pack cellulose, and 2 to 4 inches of rigid mineral wool or polyiso is applied outboard of the sheathing. This is our default in most Burnaby builds.
- Double-stud wall. Two 2x4 walls separated by an air gap, deeply insulated. More expensive in framing but eliminates thermal bridging through studs.
- Structural insulated panels (SIPs). Less common; works well on simple geometries.
Roof assemblies similarly require continuous insulation strategies — overframed cathedral roofs with 12 to 16 inches of insulation are typical. Foundations require sub-slab insulation (usually 2 to 3 inches of EPS) and full-depth perimeter insulation, plus a vapour barrier above the slab.
Windows are the weakest link in the envelope on every house, and at Step 5 they need to be triple-pane with high-performance frames. Fiberglass and aluminum-clad wood frames generally outperform vinyl. We cover this in more depth in our piece on windows and glazing for a Burnaby winter.
Mechanical ventilation when the house is sealed
A Step 5 house is too tight to ventilate by accident. You cannot rely on leaky construction to deliver fresh air anymore — by design, the house doesn't leak. That means continuous balanced mechanical ventilation, almost always a heat-recovery ventilator (HRV) or energy-recovery ventilator (ERV), is non-negotiable.
The HRV pulls stale air from the kitchen, bathrooms, and laundry; supplies tempered fresh air to the bedrooms and living spaces; and recovers most of the heat from the outgoing stream. In Burnaby's climate, an HRV (rather than an ERV) is typically the right call for new builds. Sizing follows the HRAI guidelines and the requirements in CSA F326. Commissioning is part of the building permit closure, not optional.
For a deeper look at how heat pumps and HRV/ERV systems integrate in a Step 5 Burnaby home, see our companion post on heat pumps and HRV in a modern Burnaby custom home.
Performance vs prescriptive
The BC Building Code allows two paths to compliance. The performance path uses energy modelling (HOT2000 or equivalent) to demonstrate the home meets the MEUI and TEDI limits. The prescriptive path publishes a specific recipe — wall, roof, window, mechanical ratings — that, if followed, deems compliance.
For Step 5 the performance path is almost always more flexible and more economical. It lets the design team trade — better windows for less wall insulation, for instance — based on what makes sense for the lot, the orientation, and the architecture. We work with an energy advisor registered with Natural Resources Canada from schematic design forward, not after drawings are done.
The energy advisor's role — and when to bring one in
The energy advisor is the professional who produces the HOT2000 energy model, submits compliance documentation to the City, and conducts the blower-door tests. In most markets outside BC, the energy advisor shows up late — after drawings are complete, sometimes after permit is submitted. That's the wrong time.
At Step 5, the energy advisor needs to be on the team from schematic design. The reason is orientation. A west-facing wall of glass that looks beautiful on a north-facing lot performs very differently than it does on a south-facing one. The energy model tells you which design decisions move the needle and which don't. On a Step 5 project, we share the schematic energy model with the homeowner at design development — not as a compliance checkbox, but as a design tool. It shows where the energy is going and where the intelligent investments are.
The advisor also does the pre-drywall blower-door test — before insulation is sprayed, before drywall goes up, while the frame is still accessible. This is when leaks in the air-control layer can still be fixed cheaply. A failed pre-drywall test is not a crisis; it's a correction list. A failed test at occupancy means cutting drywall.
Ask any builder you're considering: do you bring the energy advisor in at design, or after permit? The answer tells you whether Step 5 is part of how they build or a compliance problem they solve at the end.
What Step 5 actually costs versus Step 3
The honest answer is: less than most homeowners expect, if the decisions are made at the design stage.
The incremental cost of building to Step 5 versus Step 3 on a typical Burnaby custom home — assuming the team is fluent in Step 5 and the design is written for it from the start — is generally in the range of $15,000 to $40,000 depending on size, complexity, and orientation. The biggest variables are the window specification (triple-pane versus double) and the continuous exterior insulation strategy.
What that cost buys: a home that costs substantially less to heat and cool, that has no cold walls or condensation problems in winter, that is acoustically quieter because the envelope is tight, and that will comply with code requirements as they tighten through 2030 and beyond. Windows and envelope are the decisions with the longest lives in a custom home — the choices made now will still be in the walls in 2055.
The builders and architects who pitch "Step 3 is cheaper" are usually right in the short term and wrong in the 10-year term. A Step 3 envelope on a Burnaby hillside in 2026 will need meaningful remediation by 2036 as Step 5 becomes the retrofit standard for permitted alterations.
Working with a builder fluent in Step Code
Step 5 reveals which builders have updated their methods and which haven't. The signs we look for in colleagues — and that homeowners can ask about:
- Does the builder do a pre-drywall blower-door test? If not, the final number is a guess.
- Does the builder coordinate the air-barrier strategy with the framing crew before framing starts? If the strategy lands when walls are up, it's already late.
- Does the builder name an energy advisor on the team from schematic design?
- Has the builder delivered Step 5 homes in the local market (Burnaby, Vancouver, Coquitlam, North Vancouver)? Hot climates and prairie dryness behave differently than the BC south coast's wet winters.
A builder fluent in Step Code is also fluent in moisture management. The same techniques that make a house airtight can trap moisture if vapour-management isn't right for the climate. The west coast doesn't forgive this kind of mistake.
What this means for you as a homeowner
You don't need to memorize ACH50 numbers or read Section 9.36 of the BC Building Code. What you should ask any builder you're interviewing for a Burnaby custom home is: show me the airtightness number on your last three completed homes, and tell me how you got there. The answer separates the builders who hit the target every time from the builders who get close and ask for a code variance at the end.
If you're early in design and want to understand how Step 5 will shape the choices you'll make over the next year, reach out. We'll walk you through what the envelope, mechanical, and finish decisions look like at this performance level, and where the homeowner has flexibility. For the broader context on what changes in the construction process when performance is measured, why we don't believe in builder-grade and materials that age beautifully cover the durability side of the same conversation.
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