Wimbish Passivhaus, Essex

Our 14 homes completed in 2011 in Wimbish, Essex, were the first rural affordable homes to be built to Passivhaus standard in the UK.

Passivhaus is a design methodology promoted by the Passivhaus Institut in Darmstadt, Germany, for ultra low-energy, healthy and comfortable buildings. The majority of Passivhaus buildings are in Germany and Austria so, at the time, this was an exciting and ground-breaking project that brought together organisations with a range of skills and interests in sustainable development.

In order to be certified as Passivhaus, properties must have:

• very good levels of insulation with minimal thermal bridges
• well thought out utilisation of solar and internal gains
• excellent level of air tightness
• good indoor air quality, provided by a whole house mechanical ventilation system with highly efficient heat recovery.

The development

Hastoe carried out a housing needs survey which identified a strong local need. Following initial meetings with Wimbish Parish Council, a landowner of a greenfield site was then contacted with the support of Uttlesford District Council. The homes were built using the Rural Exception Site Policy ensuring the development provides affordable homes for local people in perpetuity since those allocated the housing need to demonstrate a strong local connection. Shared owners are not able to buy more than 80% of their home. Funding was provided by the Government’s Homes and Communities Agency with further investment from Hastoe.

Architectural design

The dwelling forms were kept deliberately simple to avoid thermal bridging risks. Porches, meter boxes and brise soleil are all independently supported to avoid penetrating the insulation overcoat. East/west orientation of the blocks facilitates passive solar gains, with careful attention to shading to avoid summer overheating.

Construction

Bramall Construction built the homes to a set of exemplary industry standards including: Level 4 of the Code for Sustainable Homes; the Homes and Communities Agency’s ‘Design and Quality Standards and Strategy’; the Joseph Rowntree Foundation ‘Lifetime Homes’ standard; and the Commission for Architecture and the Built Environment’s ‘Building for Life’ standard.

Ongoing monitoring and assessment

Hastoe has been monitor and learning from the performance of the homes over a number of years. A 10-year in-depth assessment was carried out in 2021 and the results, published in April 2022, showed the homes continued to be comfortable, healthy and economic to run. A resident survey found the heating bills of some residents were only £30 a quarter.

The findings of all the reports are published below.

Read more about our building standards

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