Meeting the targets
A three-step approach to meet tough performance targets.
The design and renovation specification set tough performance targets while requiring the original character of the building to be retained.
Low carbon materials and intelligent products were incorporated along with a digital communication infrastructure to monitors the condition and performance of the building and provides tele-assisted care for those needing it.
The refurbishment energy target is:
- SAP - minimum of 80
- CO2 - ≤35 kg/m2/yr
- Air permeability 7 m3/hour/m2 at 50 pascals or below (current best practice is 5 m3/hour/m2 at 50 Pascals or below)
- Energy saving - greater than 60%
- Energy production (conventional) - high efficiency gas condensing boiler with state of the art zone controls
- Energy production (renewables) - at least 10% of energy demand
The three-step approach, beginning with fabric solutions is recognised as the most effective way to improve energy-efficiency in a building:
The heat lost through uninsulated solid walls is typically over 50% greater than through uninsulated cavity walls so the emphasis was on improving the thermal performance of the fabric, through a variety of means, including internal and external insulation for roof, walls and floors. Windows and doors are another major source of heat loss, particularly old hard-to-treat, which have single-glazed sash windows. The project has installed timber, composite, UPVC double and triple-glazed windows.
Then heating and hot water
The building uses a range of different heating and hot water solutions, including air-to-air and air-to-water source heat pumps; heat phase-change materials in ceiling tiles; a condensing combination boiler with a mechanical heat save device.
Sympathetic renewables, like the solar thermal panel installed on the roof, have been chosen to complement the building and reflect the constraints that householders are faced with when choosing these innovations.