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I’m currently living in a bungalow and thinking about tearing it down to build a two-storey house on the same footprint, using the existing foundation. The current foundation is about 24 inches deep with 10 inches of concrete. I’ve heard the modern standard is closer to 36 inches. Can I build on these existing foundations or would they need to be replaced?

We had a 19 year old Carrier 80,000 BTU 80% efficiency replaced with a Trane S9V2 60,000 BTU 96% efficiency and it doesn’t seem to keep the house warm. I asked the contractor for the CSA F280 information and they won’t give it to me. I did a rough J load calculation and came up with 72,000 BTU needed, due to old windows and poor insulation. I told them I didn’t think the furnace would be big enough, but the contractor said it’s just an 1100 sq ft. bungalow. Am I right? Should I program offsets in the Honeywell T4 thermostat and try to be happy? The night time temperature dipped to 17.9C with the furnace set to 20C, daytime temperature is set to 22C and it never coincides with indoor temperature.

I bought a house 2 weeks ago but about 60% of the hardwood flooring is squeaking. I would like to have the house finish for Airbnb. Is it best to repair and refinish all but vinyl flooring ?