Renovation not demolition: a case study of saving carbon on a private residence

Abstract

This article describes a residential project to create a spacious, contemporary family home on the site of a 1960s building, following an early decision to renovate the existing structure, retaining as much of the fabric as possible. The design approach aimed to simplify the form of the building while also improving its thermal performance and airtightness. Existing masonry walls were retained on the front and side elevations, while internal walls were removed to create open-plan living spaces, requiring a steel sway frame to be installed. A new, almost fully glazed rear elevation was created, with the first-floor wall rebuilt in timber frame. Existing foundations, concrete strip footings and the concrete ground-bearing slab were largely retained. A new insulated concrete slab was installed where the ground floor was extended, and concrete was broken out locally to allow the installation of new pads where load concentrations exceeded the capacity of the existing foundations. A carbon assessment indicates that the renovation scheme saved around 45% of the embodied carbon of a hypothetical rebuild scheme, with a footprint of 111kg CO2e/m2 compared with 199kg CO2e/m2 for the rebuild scheme.