Low-Energy Homes – case studies
A low-energy house is characterised by an energy-efficient design and technical features which enable it to provide high living standards and comfort with low energy consumption and carbon emissions.
Traditional heating and active cooling systems are absent, or their use is secondary. Whilst low-energy houses may include renewable energy generation, enabling them to become zero carbon, their building design usually follows the ‘fabric-first’ approach of reducing the heat / energy loss from the building envelope before other eco-measures such as installing solar PV panels.
The UK has a number of voluntary low energy building standards – Code for Sustainable Homes (CfSH – being withdrawn), Passivhaus, AECB, Energiesprong, BREEAM etc. Of these, Passivhaus (PH) certification is considered the gold standard.
Examples of successful low-energy housing schemes are illustrated below:
Ditchingham Housing Association homes
14 units in small rural Passivhaus scheme built by a housing association
The Ditchingham scheme is made up of 14 rural exception site dwellings in a single curved terrace, built to Passivhaus standards. This £1.7m development built in 2013 is set on a challenging site in a conservation area and adjacent to Grade II listed buildings.
Innovative foundation and floor slab detailing, and the use of a 300mm fully‑insulated cavity, along with simplicity of detailing and construction (including the MVHR inlet housed in the ‘chimneys’ for aesthetic effect) have helped to deliver the exacting Passivhaus performance and reflect the local heritage.
The resulting homes cut fuel bills and carbon emissions by 90%, compared to the average UK home whilst delivering good indoor air quality and providing a very comfortable internal environment.
Knights Place Council flats, Exeter
18 units in a residential block of council housing flats built by a local Council to Passivhaus standards
These 18 flats were the first affordable, multi-residential buildings in the UK to be certified to Passivhaus standards in 2010 at a cost of £2.1 million.
The holistic passivhaus design strategy allows the units to be operated without a conventional heating system. At the same time, it will avoid overheating in the summer and aims to have a minimal environmental impact. This is exemplar sustainable council housing , with a contemporary interpretation of vernacular residential housing, that is warm, energy efficient and is fully accessible according to Lifetime Homes Standards, specifically intended to encourage existing council tenants to down-size.
Goldsmith Street Council housing, Norwich
105 units in this award winning passivhaus council house scheme in Norwich city centre.
Winner of the 2019 Sterling Prize for Architecture, this council housing scheme was designed for the 21st Century as an affordable high-density alternative to apartment blocks. Located close to Norwich city centre, the £14.7m Goldsmith Street development comprises 7 blocks aligned in 4 simple rows on a traditional street pattern, containing a total of 45 houses and 60 flats, within an area of less than one hectare. The passivhaus design means energy costs are around 70% cheaper than average. The community centred design has the back gardens looking onto a planted alley, dotted with communal tables and benches, while parking has been pushed to the edge of the site, freeing up the streets for people, not cars. “A modest masterpiece” is how the RIBA Stirling prize judges described the project.