Insulating and electrifying our house

Our house will stop burning gas by the end of 2024.

Year Gas consumption (kWh)
2023*2,865↑ 25%

*2023 consumption from 1st January to 17th October 2023. Comparison is for the same period in 2022.


In November 2022 we had a Retrofit Assessment from People Powered Retrofit. This gave us a great roadmap to a fossil-fuel-free house. It also alerted us to big problems with our ventilation and air quality.

We’ve chosen to improve these areas:

  • Ventilation - in progress
  • Loft - autumn 2023
  • Windows - autumn/winter 2023
  • Walls - autumn/winter 2023
  • Heat pump - spring 2024

Progress so far:

Next up, roughly:

  • Replace loft hatch with air-tight model.
  • Install mechanical ventilation to balance air-tightness efforts.
  • Replace knackered uPVC windows with triple glazing with insulated reveals, cills & heads.
  • Re-do loft boarding and install 350-400mm² mineral wool insulation.
  • Replace roof soffits including wind diverters.
  • Replace hot water tank with unvented type.
  • Install ~4kW heat pump.


Progress log and notes

August 2023

  • signed contract with People Powered Retrofit to make a Home Retrofit Plan
  • sent window dimensions and layouts to Ecospheric for initial price
  • cleared a load of wood from loft in prep for replacing boarding
  • measured joists, trusses, loft hatch etc and modelled in Sketchup
  • ordered air tight loft hatch (AT15) with U value 0.15 W/m²K
  • received new loft hatch. measured and double checked dimensions.
  • destroyed removed architrave from loft hatch
  • Ordered 6mm thick timber to reduce the width of the loft hatch between joists. The new airtight loft hatch needs a very precise hole to mate with its foam seals.

September 2023

  • Emailed:
  • Installed timber strips into loft hatch, flush with ceiling plaster.
  • Installed loft hatch into position. The ceiling needs fixing but the position and seal look good.
  • Drew dMEV design onto floorplan
  • Finished draft ventilation design, sent to People Powered Retrofit
  • Ordered ventilation fans, acoustic ventilators, CO₂ sensors
  • Emailed Retrofit Windows in Shrewsbury (suggested by Ecospheric as they offer supply and install)
  • Pestered People Powered Retrofit to start the Home Retrofit Plan