Thermal renovation in Westminster: of 103,000 dwellings, isolating the roof, then the walls, then the windows earn 54% more than the reverse order

Based on the energy diagnostics alone, a CatBoost model estimates the savings of each work with their uncertainty and shows that the order of construction sites counts.

In order to decarbonize the residential park, communities need to know what envelope work is best, and with what margin of error. Yunfei Bai, Wei He and their colleagues have built a framework that converts the expected changes in UK energy diagnostic notes (SAP for cost, EI for emissions) into financial savings and emission reductions, after insulation of walls, roof or window replacement. Six machine learning models were trained out of 17 certificate descriptors, and each one's errors on similar housing are used to calibrate prediction intervals.

What the numbers say

Based on 103,414 registered housing units in the London district of Westminster, CatBoost was the most accurate, with an average error of approximately 3.5 SAP points. Roof insulation offers the largest savings per dwelling, about 203 pounds per year, while wall insulation is the most cost-effective on a park-wide basis, with nearly 6.1 million pounds saved each year.

For the 5,382 housing units that need the three interventions, the final result is the same regardless of the order, but not the path: by creating roof, walls and windows at one year apart, the cumulative savings over three years are 54% higher than by doing the opposite. To help communities prioritize and sequence projects.