Heritage Home Renovation

The Thompson family home is a fine example of early twentieth-century Arts & Crafts residential architecture: hand-made clay tile roof, original Crittall steel windows, exposed oak beam ceilings, intricate plaster cornicing, and a sweeping staircase of hand-turned oak balusters. It is also a draughty, expensive-to-heat, energy-hungry building with an EPC rating of F — the second-lowest possible grade.

The brief from the Thompson family was deceptively simple: make our home warm, affordable to run, and as sustainable as possible — without touching anything that makes it special. For our heritage renovation team, this was the most rewarding kind of challenge: using the full depth of our technical knowledge to deliver radical performance improvements through entirely invisible interventions.

The thermal envelope upgrade began with the installation of blown-in sheep's wool insulation into the existing timber-framed walls via discrete drilled holes — a technique that adds no internal wall thickness and leaves period plasterwork completely undisturbed. Sheep's wool was selected over mineral fibre alternatives for its superior moisture-buffering properties, vapour permeability, and embodied carbon credentials.

The original Crittall steel windows — a defining character feature of the property — were sensitively retrofitted with slim-profile secondary glazing on the interior face, achieving near-double-glazing thermal performance while preserving the windows' original external appearance and satisfying the listed building consent conditions. Draught-proofing of all windows, doors, and floor perimeters was carried out with meticulous care, reducing uncontrolled air infiltration by an estimated 74%.

The gas boiler was replaced with a 9kW air source heat pump paired with a weather-compensated underfloor heating system installed beneath new lime screed floors in the ground floor extension. The original radiators on the upper floors were replaced with oversized low-temperature radiators optimised for heat pump operation. A whole-house MVHR system was discretely installed within the existing roof void, providing continuous filtered fresh air without heat loss and eliminating the condensation and mould issues that had affected several bedrooms.