Thermal Strategy Development – Malvern Hills

Working with Gretco Limited and Environmental Building Systems, we’ve refined the thermal strategy to achieve exemplary energy performance whilst protecting historic fabric.

The approach uses Thermafleece a breathable sheeps wool-fibre insulation above the new suspended ceiling, and within wall linings creating a continuous thermal envelope without encapsulating historic roof timbers. This allows the roof void to ventilate naturally, preventing moisture accumulation and timber decay.

Energy modelling demonstrates significant benefits:

• Air source heat pump specification: 2 x WPL 25 AS units (Stiebel Eltron)
• Annual CO2 emissions: 958g (compared to 9,506g for oil heating—a 90% reduction)
• The ceiling installation provides an additional 30% efficiency saving versus heating the full volume
• Low-temperature underfloor heating enables optimal heat pump performance

The strategy exemplifies how heritage buildings can achieve contemporary energy standards through thoughtful design rather than aggressive fabric intervention.