The buildings in the study were developed by South Yorkshire Housing Association (SYHA) and consisted of 22 properties, 18 for rental tenants with the remaining 4 for shared ownership.
It is a traditional designed and procured development which meets Level 4 of the Code for Sustainable Homes. The properties are predominantly off-site manufactured and assembled on site. Thermal mass considerations have being taken into account through a combination of either cedar cladding or brickwork finish to the external facades. The properties benefit from large, high performance, double glazed picture windows to maximise levels of natural light entering the properties. High ceilings are a feature on the first floor to make the space more impressive which also helps to mitigate the effects of overheating if present. Some of the properties have an inverted design where the kitchen and sitting room is located on the first floor with all bedrooms and bathroom on the ground floor.
Timber frame panellised system using on-site modern methods of construction (MMC) were employed. External facades use cedar panelling or brick with blockwork in the inner leaf separated by an insulated 75mm cavity. Suspended floors consisting of timber joists and chipboard are used. The roof consists of integrated modular PV panels and tiles with 200mm of mineral wool insulation between the joists and a further 200mm on top (400mm total).
The properties have been deliberately orientated to benefit from south facing roofs which are both offset and symmetrically pitched at 35 degrees. A 2.4 kWp photovoltaic (PV) array is integrated into the roofs. Two electricity meters are provided, one for grid consumption and one to cover generation from the PV arrays. The PV has been designed to supply, on average, up to 1938kWh of electricity per annum. Mains gas fired condensing boiler and radiators, natural cooling with mechanical ventilation.
The Green Corridor (www.thegreencorridor.org.uk) has supplied funding to enable SYHA to improve the environmental performance of the properties (i.e. fitting water saving taps, rainwater harvesting, installation of renewables). The Green Corridor is a housing led project, developed by Doncaster, Barnsley and Wakefield local authorities for an area of Yorkshire which has a common rural mining legacy, a need for regeneration in parts and a strong future because of location and accessibility.
The following is a summary of the scope of the project in Work Packages (WP). The BPE study mainly concentrated on plot 5 for the building fabric testing:
• WP1 Design and construction audit, drawings review: Review concentrated on 2No. 3b4p properties as these are of more benefit to SYHA (only 2 No. 4b6p properties were built and the majority of their developments consist of 3b4p properties). It concentrated on plots 5 and 6 which have different construction detail on the upper level (brick/cedar cladding)
SAP calculation review: Review concentrated on 1 No. 3b4p property as in-depth information will be obtained from WP3 below. Plot 5 was selected as the construction detail is more relevant to the future aspirations of SYHA
• WP2 Air permeability test, whole house heat loss test, in-situ U value measurement, infra-red thermography:
• Review concentrated on 1 No. 3b4p property with an adjacent 3b4p property also held back for assisting the test.
• Heat flux sensors were used to determine heat flux data with a minimum of three sensors per wall for cross reference
• A CO2 decay test was conducted to validate the co-heating results and estimate background ventilation (air changes per hour, ACH)
• A detailed analysis of the water harvesting system was conducted by a water conservation expert. The findings of this study will not only be useful in this project but also to future developments by SYHA (it is a mandatory part of the CSH)
• WP3 Evaluation of hand-over process and guidance to occupants: A simulated handover was conducted on a similar property to the test property (plot 5)
• WP 4 Qualitative Semi-structured interviews/walkthroughs with occupants and design team, photographic survey: This concentrated on the test property (plot 5) and adjacent property (plot 6) for the design team. The walkthrough with occupants was conducted on different properties as plots 5/6 were unoccupied.
• WP5 Review of system design and implementation (commissioning checks): This concentrated on the test property and a simulated commissioning check was conducted using a suitably qualified building services engineer. Services are similar on all of the 3b4p properties
• WP 6 Standardised housing survey (BUS):All properties were included that were occupied