Basement Renovation

Before any framing goes up, we read the moisture story. Visible efflorescence on the foundation walls, staining at the slab-wall joint, musty smell after a long rain, condensation on cold-water pipes — each one tells us something about how water is moving in and out. The fix can range from regrading the soil around the house and extending the downspouts, to installing or upgrading the perimeter drain, to applying interior dampproofing membranes before insulation goes on. On homes built before perimeter drains were standard, we sometimes recommend exterior excavation and new drain tile before finishing — it's invasive, but it's much less invasive than tearing out a finished basement in seven years.

If the basement is going to contain a bedroom — for a kid, a guest suite, or a secondary suite — BC Building Code requires an egress window in each sleeping room sized to allow occupant escape and emergency-responder entry. The exact unobstructed opening dimension and sill-height limit are spelled out in the current BC Building Code; we confirm the spec with your designer against the current edition rather than working from memory. On most older Burnaby basements that means cutting an enlarged window opening in the foundation wall and excavating a window well outside — a project in itself, with structural lintels above the new opening and a code-compliant ladder if the well is deep enough to require one.

Basements in older Burnaby homes often have ceiling heights that don't meet the minimum required by BC code for habitable space — sometimes by inches, sometimes by more. The two paths are: design around the existing slab and accept that some rooms (storage, mechanical) live in non-habitable space, or lower the slab. Slab lowering is a real piece of work — under-pinning the existing footings, breaking out and removing the old slab, excavating, pouring a new slab at the lower elevation. It's the kind of project where the math has to work, because it's never trivial. We'll walk you through it honestly before recommending it.

A rec room is part of the principal dwelling; a secondary suite is a self-contained dwelling unit with its own kitchen, bathroom, and entry, and in Burnaby it requires registration as a legal secondary suite under the city's secondary suite program. The bylaws cover separate entry, smoke and CO alarm interconnection, fire separation between the suite and the main dwelling, parking requirements, and limits on suite size. We work the scope against the city's current secondary-suite requirements early — designing a suite that almost qualifies and then trying to fix it at final inspection is the worst path. If a suite is the goal, the plans go in as a suite from the start.

When the basement is open to studs is the only practical moment to upgrade the envelope below grade. Continuous rigid insulation on the interior face of the foundation walls (with the right vapour-control strategy for an inboard-of-concrete assembly), insulation under any new slab where applicable, and air-sealed rim joists at the floor-above transition. Done together, these change a basement from a heat sink into conditioned space that doesn't drag the whole house's energy bill up. Mechanical follows from there — extending the home's existing heat pump or furnace, adding a dedicated zone, or running a small mini-split for the basement rec area depending on layout. Skipping the envelope upgrade because 'we just want to finish it cheap' is how we end up redoing the basement in eight years.