Toronto Basement ???? Return air grates can be found in many sizes for approximately $5 at home centers. Test the sizes of accessible grates and body the accesses somewhat scaled-down. It depends on your budget and what finishes are now in the basement. Most renovations include insulation and humidity Management. https://medium.com/@a.l.e.xzhi.gl.at.y/luxury-living-below-elevate-your-toronto-home-with-a-basement-renovation-fit-for-royalty-18340e425584