Basement Design in 3D
A basement is built from the concrete outward, and every layer covers the one before it. Drag this one around to look at it, then step it back through the drywall, the vapour barrier, the batt and the framing until you are down to the foam against the foundation.
The arrows on the model step through the build, from the foam against the concrete up. Drag the room itself to turn it, over the top or underneath. The ceiling is left off so you can see in.
Phases
What is behind the drywall
A basement wall in Central Alberta is built in layers, and the order matters more than any single piece of it. Rigid foam goes against the concrete first, because that is what keeps the framing away from a cold, damp surface. The bottom plate is treated, because it sits on the slab. Studs run at 16" OC with batt between them, and a vapour barrier covers the whole face before a sheet of drywall goes near it.
Every one of those layers is finished work that nobody sees again, which is the honest difficulty with quoting a basement. 2 jobs that look the same when they are done can be built very differently, and all of the difference is now covered up. While it is still a drawing a wall costs nothing to move, and on most layouts we move two or three of them before anybody is happy.
There is a bathroom drawn the same way if that is the room you are planning. It picks up where this one stops, at the board, and goes on through the waterproofing and the tile. There is a kitchen too, which starts finished and shows what had to be settled before the cabinets went in, and an addition built from the foundation up, with a full basement under it as one of the options.
The model above is a development we drew to show the sequence, not a job we built for somebody. The 857 sqft basement we developed in Red Deer is one we did build. If you are planning a basement and the layout is still open, we are happy to talk it through. Get in touch or call (587) 447-9009.
Questions we get asked
- What makes a basement window big enough to count as an egress window?
- Two things, and both have to be true of the part that actually opens: at least 3.8 sqft of clear opening, and no dimension under 15". The catch is in the hardware. A crank window opens the whole hole, so the glass size and the opening are close to the same. A slider or a hung window only ever opens half of itself, so a unit that looks generous on the wall can fail on the measurement. Any bedroom below grade needs one, and it is the requirement most often missed on a basement.
- What actually goes into a finished basement wall in Alberta?
- Working out from the concrete: 1 1/2" of rigid foam against the foundation, a treated bottom plate, 2x4 studs at 16" OC with batt insulation between them, a vapour barrier over the whole face, then 1/2" drywall. That is five layers and a plate, and once the drywall is on you never see any of it again. You can strip the model on this page back through every one of them.
- Why does the vapour barrier matter so much here?
- Because of where the dew point sits in a cold climate. Warm indoor air holds moisture, and if it reaches a cold surface inside the wall that moisture turns to water in the stud bay where nothing can dry it. The barrier keeps that air out of the assembly. It goes up in an afternoon, it is invisible ten minutes later, and it is the single layer in a basement wall that is hardest to put right afterwards.
- How low can a basement ceiling be?
- The showcase on this page is built at 8'-0" from slab to underside of joist, which is a common height in a newer Central Alberta home. Older houses are often lower, and the height you have left after the floor goes down is what decides whether a dropped bulkhead over a duct run feels like a design choice or like a low spot you keep noticing. It is worth measuring before anything is planned.
- Why does the floor go down after the walls in a basement?
- Because the framing stands on the slab. The bottom plate sits straight on concrete, which is why every one of them down there is treated lumber rather than ordinary spruce, and the floor goes in afterwards between walls that are already boarded and painted. You can follow that order on the model above. What usually goes down first is an insulated subfloor panel: a strand board face on a dimpled mat that holds a small air gap over the concrete. The gap is the whole point of it. It keeps the finished floor off a slab that is always a few degrees cooler than the room and gives any moisture somewhere to go, and it is most of the difference between a basement that feels like a room and one that feels like a basement. If there is going to be heat in the floor, that gets decided before any of it goes down, because it is the one part of this you cannot add later without taking the floor back up.
- Do you draw every basement in 3D?
- Not every one. The design phase is its own piece of work, and where it earns its place is when the layout is genuinely undecided: you are weighing where a bathroom goes, you want to see a bedroom with and without a walk-in, you are trying to picture how a stair landing eats into a rec room, or there are two of you deciding and you are each imagining something different. While it is still a drawing, moving a wall costs nothing. On a straightforward development where you already know the layout, we are happy to skip it and get building.