56 and 58 Elliott Drive are two semi-detached non-traditionally constructed (Wimpey No-fines) properties built in the 1950‟s, located in rural Warwickshire and owned by Orbit Heart of England.
One of the properties was retrofitted to the German Passivhaus ‘EnerPHit’ retrofit standard. The EnerPHit standard is newly defined and this home is the second ‘general’ and first ‘social housing’ property in the UK to achieve this extremely high standard. The heat energy consumption target is 25KWh/m² per annum with No.58 achieving 23KWh/m² per annum – a tremendous reduction in heating fuel costs from the original!
On this property a Wetherby Epsiwall system incorporating a massive 200mm of Kingspan K5 EWB was utilised (bearing in mind that most hard to heat properties in the UK only require 60mm to bring them in line with current building regulations). Again the insulation was encapsulated with a WBS 1.5mmK silicone thincoat render system, providing a watertight, modern finish.
As the Passivhaus standard requires low levels of heat loss through natural ventilation, the home is provided with a mechanical ventilation and heat recovery (MVHR) system, which warms incoming fresh air through a heat exchanger. In addition the house is extremely air-tight avoiding heat loss through small gaps and holes in the building components and structure - although this requires a high degree of quality of workmanship by the construction team. With an air permeability rate of 0.53m3/hr/m2 compared to Building Regulation requirement of 10m3/hr/m2 @ 50 Pascals, this is testament to the high degree of workmanship achieved.
The refurbishment provides a long term (future proof) solution when compared to conventional approaches by going far beyond current regulatory standards, requiring only minimal maintenance requirements during its expected life (60 years).
