Before retrofit: BER D2
After retrofit: BER A3
The challenge: The windows are double glazed aluminium with a double glazed aluminium back door and single glazed wooden front door. The floors are suspended with the kitchen and bathroom appearing solid. There is oil fired central heating with single panel steel radiators and a gas fire fitted into an open fireplace. The cavity wall construction consisted of a smaller cavity which is pumped and the attic is insulated.
Property Type: Detached Bungalow
Year of Build: 1966
Homeowner Goals: Working with a set budget, to future proof a 1960’s vacant property to current standards of comfort including internal layout changes and a polished concrete floor finish throughout creating a warm, comfortable and healthy home that would retain heat. A key requirement was that the character of the building would be retained.
Before & After Retrofit Summary
| Category | Before Retrofit | After Retrofit |
| BER Rating | D2 | A3 |
| Overall Comfort | House was vacant. Appeared cold and draughty with ample opportunity for heat loss. | Consistently warm, comfortable and stable internal temperatures |
| Heating System | Oil‑fired central heating with gas fire | 6kW air‑to‑water heat pump with modern controls and underfloor heating throughout |
| Fuel Type | Fossil fuel (oil) | Electricity with renewable contribution (heat pump) |
| Insulation – Attic | Approx 200mm | Upgraded attic insulation to minimum 300mm |
| Insulation – Walls | Cavity with full fill insulation | Full fill cavity wall construction with Internal insulation completed throughout. |
| Windows & Doors | Double glazed aluminium windows with a double glazed aluminium back door and single glazed wooden front door | High‑performance triple‑glazed windows and doors |
| Airtightness | Significant uncontrolled draughts, gas fire open to chimney, suspended floor. | Airtightness measures implemented, insulated concrete floor with underfloor heating installed and chimney sealed |
| Ventilation | None. Extract Fan in kitchen. | Extract fans in wet rooms with humidity sensitive background vents in habitable rooms. |
| Indoor Air Quality | Unknown, would appear poor. | Natural ventilation through background vents with moist air extracted through extract fans. |
| Pipework | Gun barrel | New pipework through underfloor heating installation. |
| Electrical System | 1960’s standard | Full rewire. Meter moved externally and mains cable upgraded. |
| Renewable Energy | None | Contribution via heat pump. |
This project demonstrates how an independent, whole‑house approach can transform an older bungalow into a comfortable, energy‑efficient A‑rated home.
