Murray Warner, Partner at Hardies Property & Construction Consultants, provides a sustainable housing development case study.
Partridge Walk is a development of three houses epitomising sustainable building and modern living in an elevated setting, overlooking Poole Harbour, Dorset. Combining contemporary architecture with modern construction techniques and materials, Partridge Walk will create environmentally friendly, fully sustainable, thermally efficient properties.
The houses have also been designed and sited to best practice passive design principles. They benefit from an east/west orientation, which provides high levels of lighting throughout the day, thus minimising the need for artificial light. Protective shading from the sun is provided by the roof overhangs on the first floor whilst maximising solar gain in the winter months.
A 6kW photovoltaic solar panel system is set behind a low parapet on each house. The power generated by the system is stored by a ‘Tesla Powerwall v2.0’ that will run the ‘Smart Building System’; an holistic automation system that allows the building services to communicate with each other wirelessly throughout the property via Bluetooth 5, providing essential energy saving feedback to a live server to continually evaluate the energy needs of the building, adjusting levels to optimise energy savings.
The ultimate outcome is no energy bills to the owner and zero impact on the local infrastructure. The system design will far exceed the required minimum 10% renewable energy generation required by Policy PP37: Building sustainable homes and businesses.
The plant room is the nerve centre of the house. An ‘exhaust air heat pump system’ extracts warm, stale air from the bathrooms, kitchen and utility room passing through a series of ducts running within the floor and walls. The boiler units use a built-in ‘air source heat pump’ to scavenge waste heat and make domestic hot water heating highly efficient; it offers a saving of up to 75% of the average home’s cost. Connecting to the solar energy generation will achieve the highest levels of energy efficiency (A+++).
Exploiting thermal mass on a year-round basis required consideration at the outset of the design process when requirements for the building form, fabric and orientation were established. With a more passive approach to design, the benefits achieved include:
- Enhanced fabric energy efficiency and carbon savings over the life of the building Improved day lighting, a highly cost-effective means of reducing the energy for electrical lighting and cooling
- Improved ventilation and air quality circulation, through air conditioning management Optimising decrement delay and decrement factor, in reducing heat gains in summer by controlling decrement delay and preventing the overheating of the building
- A sustained measure of future proofing against the effects of an increasingly warming climate Reducing the need for more expensive low- and zero-carbon technologies to meet lowering CO2 targets.
- The proposed construction method uses structural insulated panels for walls and roofs which far exceed the minimum elemental U-values as defined in the Building Regulation Part L. The Partridge Walk development will use a combination of two and three sash double and triple rack Ultraglide sliding doors by Smart Systems incorporating highly efficient thermal breaks which will achieve between 0.85W/m²K and 1.1W/m²K thermal values to further enhance the low emission and increase the EPC rating to AAA.
Hardies Property & Construction Consultants is providing Quantity Surveying and Principal Designer services to the development. The properties, designed by Ström Architects and built by Kubö Homes, showcase ecologically-manufactured building materials and ecologically-focused management systems. This is a ground-breaking development that showcases a commitment to reducing carbon emissions and creating carbon-negative homes.
For more information on the project, visit hardies.co.uk or contact Murray Warner on tel +44 (0)131 557 9300