Eco-Friendly Options for Your London Home Renovation
Sustainability is increasingly front-of-mind for London homeowners undertaking renovations — driven by energy costs, environmental awareness, and the growing impact of EPC ratings on property value and mortgage access. Here's an honest overview of the most effective and practical eco-friendly measures for residential renovation in London.
Insulation — The Foundation of Energy Efficiency
No single measure has more impact on a property's energy performance than insulation. Heat loss through walls, roofs, floors, and around windows and doors accounts for the majority of residential energy demand. Any renovation that involves opening up walls or ceilings is an opportunity to add or upgrade insulation at relatively low marginal cost.
Roof and loft insulation. The simplest and most cost-effective improvement in most properties. A loft conversion or roof replacement is the ideal time to install the maximum practical depth of insulation. Mineral wool, rigid PIR board, and spray foam (with caveats for mortgage lender acceptance) are all options.
External wall insulation (EWI). Where external rendering is being replaced or external fabric works are being carried out, adding external wall insulation at the same time is highly cost-effective. EWI wraps the building's thermal mass inside the insulation layer and avoids cold bridges.
Internal wall insulation. Where external works aren't planned, insulating internally (with a thin PIR board or a warm-wall system) is an option, though it reduces floor area slightly and requires careful attention to moisture and cold bridging.
Windows and Doors
Triple glazing is now cost-competitive with high-specification double glazing and delivers meaningfully better thermal performance. Where windows are being replaced as part of a renovation, the marginal cost of specifying triple glazed units over double is relatively modest. Ensure frames are also thermally broken — the frame accounts for a significant proportion of window heat loss.
Heat Pumps
Air source heat pumps (ASHPs) are increasingly viable for London homes and are supported by the Boiler Upgrade Scheme (BUS), which provides a £7,500 government grant towards installation. ASHPs are most effective in well-insulated homes with underfloor heating or upgraded radiators (heat pumps run at lower flow temperatures than gas boilers and require larger heat emitters to compensate).
A renovation that includes underfloor heating in the extension or ground floor, combined with improved insulation, is an excellent opportunity to size the system for an ASHP from the outset — even if the gas boiler is retained initially.
Solar PV
Solar photovoltaic panels are now cost-effective for most south, east, or west-facing roofs in London, with payback periods of 6–10 years and a system lifespan of 25+ years. A loft conversion or re-roofing project is the ideal time to install solar, as the scaffold is already in place and the additional cost of installation is much lower than on a standalone solar project.
Sustainable Materials
Specifying sustainably sourced timber (FSC or PEFC certified), low-embodied-carbon insulation materials, and recycled content products where available all contribute to reducing the environmental impact of the project without material cost premium. Your contractor's procurement approach matters here — ask the question.
RCB provides guidance on sustainable options as part of our pre-construction consultation. 07359 872594 | contact@rcbgroup.co.uk | www.rcbgroup.co.uk