ACC’s housing stock includes 59 multi-storey properties (4,800 units). Whilst the majority of the low-rise stock has been greatly improved through comprehensive upgrades, the energy efficiency of multi-storey properties has proved much harder to tackle. The options for high-rise properties are more limited, with substantial implications for capital expense and disruption to tenants.ACC also have low-rise sheltered housing (1,800 units) and amenity houses (1,500 units). Amenity houses offer self-contained accommodation with the minimal level of on-site support and are normally likely to have an alarm system rather than any warden provision. Many are hard to treat or currently house people who are fuel poor. Consequently they were seen as a high priority by ACC.
The primary objectives for these properties were to achieve affordable warmth for tenants and to reduce CO2 emissions. The initial task was to identify the most cost effective way of meeting these objectives. To begin the project the consultants chose one cluster of flats. Stockethill, comprises 288 flats, in four multi-storey blocks. The flats had electric storage heating, which had been installed in the 1970’s. 70% of the residents of these dwellings were estimated to be in fuel poverty. The tenure of these properties was 98% council tenants and 2% owners.
Having secured a Community Energy Programme funding, applied for planning permission and carried out the full tendering process, the Stockethill scheme was able to commence. An energy centre was built close to one of the four multi-storey blocks. It houses a 210kWe gas fired reciprocating engine CHP unit and two 700kW (thermal) gas fired boilers for peak load and back-up. The heat is distributed to the four blocks via pre-insulated underground pipes, which comprise the heat network. Each unit has a new internal distribution system.