Hoped to get near net zero, not even close
I’ve been planning a small 980sq ft house near Vancouver, for which I was hoping to get near net zero. It’s a rectangle with a recess on one wall and a double pitch roof. The plan was to build to level 5 of a new energy code that’s being phased in in BC. Level 5 isn’t due to be a mandatory step until ~2030. It’s basically net zero, <1.0 Ach50, <15kwh/m2. Our energy modeller has run his simulations, played with the envelope and insulation design and it’s not much more efficient than an average house. The main issue seems to be the poor volume to surface area of the enclosure ratio, where the small size of the building is actually a negative. The modeller comments that they increased insulation values but it didn’t change the outcome by much. I’m a little surprised it hasn’t come out better, but it also raises the question to me if small home builders in future will be penalised for building smaller homes The only way for my build to reach net zero is a 10kw solar system at a cost of CAD $25-30k, which is a cost I’ll struggle to ever get back in energy savings.
Was I naive to think a small house could be highly efficient without costing top dollar? If this energy code is to be standard in future how else can small homes meet these targets?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part