Thinking about underpinning? What GTA homeowners should know before digging down

Homeowners in the Greater Toronto Area are increasingly lowering basement floors through underpinning to create full-height living spaces. Underpinning involves extending foundations deeper by excavating beneath footings in sections, allowing for higher ceilings. It is costlier and more complex than bench footing but preserves more space. Costs depend on depth, soil, water table, and existing conditions. Permits, engineering plans, and waterproofing are essential. Projects take 4-8 weeks, and neighbor communication is important.