During cost calculation for new home construction in Toronto we can assume basement staying unfinished or basic type of finishes. With more detailed plan our team can give exact cost, but at start it makes sense to stay at basic. When clients ask us if per square footage cost includes finishing basement, the answer is always “no, but basement doesn’t cost as much as main floor”. The house is already construction around basement with exterior walls, slab, ceiling and required insulation. The rest is to finish it and it is fair to assume basic finishes to be within $100 per square foot of basement space.