Sustainability in construction has become a marketing battlefield. Every builder claims to be green, every material supplier has a carbon-neutral range, and every new technology promises to revolutionise energy performance. As builders who have been specifying and installing these systems for years, here is our honest assessment of what works.
Insulation is the single most impactful investment you can make. Before spending money on renewable energy systems, maximise the thermal performance of the building envelope. A well-insulated home needs less energy to heat and cool, making every subsequent technology more efficient. We routinely exceed Building Regulations minimum U-values by 30–50% on new builds and extensions.
Air-source heat pumps (ASHPs) have matured significantly. Modern units from Mitsubishi, Daikin and Vaillant deliver coefficients of performance (COP) of 3.5–4.5 in UK conditions — meaning they produce 3.5 to 4.5 units of heat for every unit of electricity consumed. Combined with underfloor heating (which operates at lower flow temperatures than radiators), ASHPs are now our default recommendation for new builds.
Mechanical Ventilation with Heat Recovery (MVHR) is transformative in airtight buildings. MVHR systems extract stale, moist air from kitchens and bathrooms and pass it through a heat exchanger, recovering 90%+ of the thermal energy before exhausting. Fresh, filtered air is supplied to living rooms and bedrooms. The result is better indoor air quality and significantly reduced heating demand. Our Riverside Walk apartments in Chelmsford achieved an EPC A rating largely through the combination of MVHR and ASHPs.
Solar PV panels are a proven technology with simple economics. A 4kW domestic system costs £6,000–£8,000 installed, generates approximately 3,400kWh per year in the South East, and typically pays for itself within 7–9 years through electricity savings and Smart Export Guarantee payments. We integrate PV into all new build designs as standard.
What does not work as well as claimed? Ground-source heat pumps for most residential projects — the additional cost of borehole drilling (£10,000–£15,000 over an ASHP) rarely justifies the modest efficiency improvement. Battery storage is improving but remains expensive relative to the electricity it displaces. And "eco" materials that cost three times more than conventional alternatives often deliver marginal performance gains.
Our approach is pragmatic: specify proven technologies that deliver measurable performance improvements at a reasonable cost premium. We will always recommend insulation before renewables, passive design before active systems, and proven products before novel ones.