Zehnder develops sustainable building in Exeter

Knight’s Place Passive House Housing is a sustainable social housing development of 18 one and two-bedroom apartments.

Built with meticulous attention to detail, the two blocks have been designed to strict Passive House standards, which deliver high comfort levels for residents via a mechanical ventilation system with heat recovery (MVHR). Knight’s Place is amongst the first multi-residential, certified Passive Housing schemes in the UK.

Design Elements and House Plans

1 Building
According to the Standard Assessment Procedure (SAP) Energy Performance Certificate (EPC), the flats in Knight’s Place can be heated for as little at £18 per year. The EPC shows that another £24 and £86 might be required for lighting and hot water per year respectively. This shows that these flats are truly affordable for future tenants.

High performance triple glazed windows and doors – maximum U-value 0.85Wm2K have been installed. Daylight design is maximised in all rooms where possible to reduce reliance on artificial light and utilise solar gain. Light coloured walls help to reflect daylight into the rooms.

The level of airtightness is exceptionally high: <0.6m3/m2.hr. Careful attention to details was necessary to ensure continuous airtight barrier.

2 Products
With MVHR an integral feature of all Passive House developments, it was essential that a highly efficient, quality MVHR system was specified for Knight’s Place, enabling the buildings to meet stringent energy performance criteria.

Offering excellent rewards in Standard Assessment Procedure (SAP) through the Dwelling Emission Rates calculation, Zehnder’s ComfoAir 200 whole house heat recovery system was specified for each apartment.

Guaranteeing the provision of optimum quality indoor air all year round, the CA200 recovers heat from the warm air extracted from kitchens and bathrooms and transfers it to the fresh incoming air supplied to living rooms and bedrooms.

The CA200 system provides both the ventilation and heating needs at Knight’s Place – no other heating system is required. As the heat loss in each flat is so minimal, this is met during winter extremes via a small air heater air duct just after the heat exchanger.

Jason Fitzsimmons, Principal Mechanical and Renewable Energy Engineer at Gale & Snowden Architects said:

“While the average unit on the market stands at around 75 to 80 per cent efficiency, Zehnder’s CA200 model offers a 92 per cent MVHR efficiency rate, which is outstanding. This, alongside its compactness, is one of the reasons we selected the unit because, for this type of dwelling, there’s no doubt that it’s the most efficient on the market.”