SC
By Sebastian Edward-West · Last updated May 29, 2026

Squamish Step Code Requirements

Current Step: 3 | ACH Target: 2.5 ACH50 | Climate Zone: transitional — CZ4 valley floor toward CZ6 with elevation | Permit Office: District of Squamish Building Department

Squamish sits in the Sea-to-Sky corridor between Vancouver and Whistler, and that geography is the single most important thing to understand before you model a new build here. The town floor along the estuary behaves like coastal Climate Zone 4 — mild, wet, a lot like the Lower Mainland. But Squamish builds happen on the slopes too: Garibaldi Highlands, the benches above Brackendale, the lots climbing toward the alpine. As you gain elevation, heating degree days climb and the climate assumptions push toward CZ6. The practical consequence is blunt: a wall and window spec that passes on a Vancouver lot does not automatically pass on a higher-elevation Squamish lot. This page is the builder-focused walkthrough that ties the Step Code to that elevation variance, and to how the District of Squamish actually runs a permit.

Why the climate-zone transition changes your spec

The BC Energy Step Code is a performance standard, not a one-size R-value list. The targets your energy model has to clear — thermal energy demand and mechanical energy use — are set by your site’s climate zone and heating degree days. Colder zones get stricter targets. That is the whole game in Squamish, because a single municipality spans a climate gradient that elsewhere would cover two or three towns.

On the valley floor, a Squamish build models close to a coastal CZ4 home: the envelope demands are the gentlest end of the BC range. Climb a few hundred metres up into the Highlands or the upper benches and the heating load rises — more degree days, longer cold shoulder seasons, snow that sits — and the model starts behaving like a colder zone. The same drawing set, dropped on a higher lot, can move from comfortable pass to marginal fail purely on the climate inputs.

So the first question on any Squamish project is not “what’s the spec” — it’s “what are the climate inputs for this site.” Confirm with your energy advisor and the District which heating-degree-day figure applies to your specific lot elevation. Do not assume a Vancouver number, and do not assume one Squamish project’s model transfers to another at a different elevation.

What’s required right now

Step 3 is the provincial minimum for all new Part 9 residential buildings in BC, and it applies in Squamish. Step 3 has been the floor since it became mandatory province-wide, and the full 2024 BC Building Code — which folded the Step Code into Section 9.36 and added the EL-1 carbon-disclosure and 26°C overheating requirements — governs permit applications submitted under the current code.

The airtightness target at Step 3 is 2.5 ACH50, verified by a blower door test before occupancy. Most builders reach 2.5 with disciplined manual air sealing and a crew that takes the air barrier seriously. For the full ladder of airtightness thresholds — Step 3 at 2.5, Step 4 at 1.5, Step 5 at 1.0 — and what each one asks of your detailing, see the ACH targets by step reference.

On the carbon side, the province requires EL-1 (measure and disclose operational greenhouse gas emissions) under the current code. Whether the District of Squamish has adopted any above-minimum Zero Carbon requirement — an emission level beyond EL-1 — is exactly the kind of local policy that changes by council decision, so confirm the current Step and emission level directly with the District of Squamish building department before you design around it. Sea-to-Sky and corridor municipalities have been active on climate policy, and treating a municipal carbon requirement as settled without checking is how a permit package gets sent back.

Coastal-to-alpine: moisture and snow load

Two physical realities of the corridor shape Squamish envelopes beyond the energy numbers.

Moisture. Squamish is wet — coastal rainfall on the floor, and wind-driven precipitation funnelling up the corridor. A tight Step 3 envelope changes how a wall manages water and vapour. When you seal a building down toward 2.5 ACH50, the assembly has less incidental drying through air leakage, so the rainscreen detailing, the vapour control layer, and the drainage plane have to be right. Tightness and moisture management are the same conversation here, not separate ones.

Snow load. Higher-elevation Squamish lots carry real snow. That is a structural-design issue first, but it touches the energy envelope too: roof assemblies, the way insulation meets the roof structure at the eaves, and the air barrier continuity across a roof built for heavy load all need to hold together. A snow-loaded roof with a sloppy ceiling-plane air barrier loses heat into the attic and invites ice damming — a comfort, durability, and energy problem at once.

Neither of these is unique to Squamish in isolation, but the combination of coastal moisture on the floor and alpine snow up-slope inside one municipality is genuinely a Squamish characteristic. Build it into the design conversation early.

Permit process at the District of Squamish

The District of Squamish building department is the Authority Having Jurisdiction (AHJ) for permits and inspections within district boundaries. The Step Code touches a Squamish permit at three points:

  1. Pre-construction. Your Registered Energy Advisor models the design in HOT2000 using the correct climate inputs for your site elevation and produces a pre-construction compliance report. Squamish is among the AHJs that expect the pre-construction energy compliance report as part of the building permit application — not as something you file later. If the energy model is not done, your application is not complete. Build the advisor into your design timeline, not your construction timeline.

  2. Mid-construction (recommended). A pre-drywall blower door test after the air barrier is installed but before drywall closes it in. Some BC municipalities mandate this; confirm with the District whether it is required or recommended for your project. Either way it is the cheapest insurance you can buy — catch leaks while the walls are still open.

  3. As-built. Final blower door test plus the updated as-built compliance report, required before the occupancy permit, along with the EL-1 GHG disclosure.

Confirm current submission requirements, fees, and whether any local checklist applies directly with the District of Squamish building department — municipal procedures and forms change, and the District’s own counter is the authoritative source.

What HDD variance means for your assemblies

Because Squamish spans a climate gradient, there is no single “Squamish wall.” Instead, think of it as a sliding scale anchored by your site elevation:

  • Valley-floor lots (coastal CZ4-like): the gentlest envelope demands in the BC range. Standard well-detailed walls and good double-glazed low-E windows generally clear Step 3 comfortably when the air sealing is disciplined.
  • Mid-slope and bench lots: more heating degree days, so the model tightens. Expect to lean harder on continuous exterior insulation and better window U-values to hold the thermal energy demand target.
  • Higher-elevation lots toward CZ6: the stiffest demands in the municipality. Thicker effective wall R-values, careful thermal-bridge control, and high-performance windows become the difference between pass and fail in the model.

Across all of them, an HRV with strong sensible recovery is effectively standard in a tight home — you need controlled ventilation once you seal the envelope, and recovering heat from exhaust air matters more the colder the site. The point is not a fixed prescriptive list; it is that the spec scales with elevation, and the energy model is what tells you where on that scale your particular lot lands.

Working with a Sea-to-Sky energy advisor

Step Code compliance reports in BC must be signed off by a Registered Energy Advisor (REA) — a third-party building energy professional certified through a service organization licensed by Natural Resources Canada. They are independent from the builder, and their stamp is what the District accepts on your compliance documents. For the full breakdown of what an advisor does at each stage, see the energy advisor guide.

A Squamish build touches an advisor at three points: the pre-construction model and report filed with your permit, an optional mid-construction pre-drywall blower door test after the air barrier goes in, and the final as-built test and report before occupancy.

The Squamish-specific instruction for that first meeting: make the site elevation and its climate inputs the opening item. The advisor does not have to be physically local — drawings can be modelled remotely, and only the blower door tests require an on-site visit — but they do need the right climate-zone assumption for your lot. An advisor who has worked the corridor will ask which bench or slope you are on before they touch the model. Bring floor plans and elevations, building section drawings showing the insulation assemblies, your wall/roof/floor R-values and vapour-barrier locations, the window and door schedule with U-values, your mechanical spec (heat source, HRV, water heater), and the lot’s elevation. Confirm the required Step, emission level, and the HDD figure up front so there is no rework when the climate inputs turn out colder than a coastal assumption.

Common compliance gaps in corridor builds

The recurring air-leakage failure points are consistent across BC field experience and apply squarely to Squamish, with a couple sharpened by the corridor’s moisture and snow:

  • Bottom plates. The gap between the bottom plate and subfloor is the single most common leak in residential framing. Seal it before the walls go up.
  • Rim and band joists. Floor-to-wall transitions, especially in multi-storey homes on sloped lots. Spray foam stops short, corners open up.
  • Ceiling-plane air barrier under a snow-load roof. Continuity here is doubly important in Squamish — leaks drive heat loss and ice damming on heavy roofs.
  • Service penetrations after drywall. Plumbers and electricians cut the air barrier without resealing. Walk the trades through the air barrier strategy on day one.
  • Window rough openings and attic hatches. Backer rod missing, sealant skipped on the warm side, no gasket. Easy fixes, routinely missed.

Builders running a pre-drywall test catch these while the assembly is still open. After drywall, the cost to fix climbs sharply — and in a tight envelope managing corridor moisture, an unsealed leak is a durability risk, not just an energy one.

What’s coming

Step 4 is anticipated as the provincial minimum for Part 9 in 2027, lowering the airtightness target to 1.5 ACH50 — roughly a 40% improvement over Step 3, and not reachable with sloppy framing plus caulking touch-ups. For higher-elevation Squamish lots, that tighter target lands on top of already-stiffer climate-driven envelope demands, so corridor builders aiming up-slope have the most to gain from learning their air-sealing numbers now. Run mid-construction tests on current builds, find where your own assemblies leak at 2.5, and you will reach 1.5 without drama when it becomes the floor. Always confirm the adopted Step and timeline with the District before assuming a date.

Frequently asked questions

What Step Code does Squamish require for a new house? Step 3 of the BC Energy Step Code — the provincial minimum — applies to new Part 9 residential buildings in Squamish, with a 2.5 ACH50 airtightness target verified by a blower door test before occupancy. The District of Squamish may set above-minimum Step or carbon (emission level) requirements by bylaw, so confirm the current requirement directly with the District building department before you design.

Why does my Vancouver house spec not work on a Squamish lot? Because Squamish spans a climate-zone transition. The valley floor behaves like coastal Climate Zone 4, like Vancouver, but heating degree days rise with elevation toward CZ6 on higher slopes and benches. The Step Code’s energy targets get stricter in colder zones, so the same wall, window, and mechanical spec can pass on the floor and fail higher up. Model your specific site elevation rather than borrowing a Lower Mainland number.

Do I need an energy advisor for a Squamish building permit? Yes. Step 3 is a performance standard, so a Registered Energy Advisor must model the building in HOT2000 and produce a pre-construction compliance report. Squamish is among the AHJs that expect that report with the permit application, plus an as-built report and final blower door test before occupancy. The advisor can model drawings remotely; only the blower door testing requires an on-site visit. See step-code-by-municipality for how Squamish compares to nearby jurisdictions.

Verify before you apply

Step Code steps, emission levels, permit forms, and fees are set by the Authority Having Jurisdiction and change with council decisions and code updates. Before you submit, confirm the current Step, any above-minimum carbon requirement, the climate-zone/HDD inputs for your specific lot elevation, and the permit documentation requirements directly with the District of Squamish building department.

Next steps for your Squamish project