A social housing estate of some hundred dwellings in Norwich, UK, has won the coveted 2019 Royal Institute of British Architects (RIBA) Stirling Prize, which is awarded to the UK’s best new building.
The prize is judged against a range of criteria including design vision; innovation and originality; capacity to stimulate, engage and delight occupants and visitors; accessibility and sustainability; how fit the building is for its purpose and the level of client satisfaction.
The Norwich’s scheme consists of 105 social homes – a mix of 45 one-bedroom flats, 40 two-bedroom houses, three two-bedroom flats and five four-bedroom flats.
The homes, owned and managed by Norwich City Council, are rented out to people with a housing need. They were built by RG Carter and designed by architects Mikhail Riches and Cathy Hawley.
They have been built to eco-friendly Passivhaus standards, ultra-low energy buildings which need very little fuel for heating or cooling.
The timber framed homes have insulation pumped into a airtight membrane, to prevent heat loss, with triple-glazed windows.
The homes are also kitted out with a mechanical ventilation heat recovery system. That is essentially a duct which comes into the building, with a fan blowing fresh air in and another duct with a fan blowing stale air out.
A heat exchanger takes the heat from warm air, produced by the likes of washing machines, televisions and body heat. It then transfers that heat to cold air, so that all rooms are a comfortable temperature.
Social housing in the UK has a bad reputation for design quality and the housing block has been praised as “the antithesis of all the poor-quality blocks that were erected in the 1960s and 1970s.”
These six buildings are very diverse in typology and scale – from a rustic stable block-turned theatre to a vast national railway station.
But they incorporate ground-breaking innovation, extraordinary creativity and the highest quality materials and detailing which sets them apart.
The eventual layout is a simple series of seven terrace blocks arranged in four lines. An immediate connection with a very recognisable urban layout, the architects were able to convince the planners to accept a narrow 14m between blocks – effectively the street width – through a careful design of windows to minimise overlooking, and a very thoughtful asymmetric roof profile that allows good sunlight and daylight into the streets.
The result is a very dense development, but one that is in no way oppressive.
Black glazed pantiles, mitred as they go from a roof covering to a wall covering, perforated metal brise soleil, and the new detailing associated with energy conscious design are wholly contemporary. The brick is also contemporary, with characteristic intentional white efflorescence colouration, set in a mews or small terrace layout.
To be certified Passivhaus, the windows had to be smaller than the proportion in a Georgian or Victorian terrace, so the architects have used a set-back panel around the windows to give an enlarged feel, and panels of textured brick have been introduced into the main elevations, again to balance the feel of the fenestration along the terrace.
Provision for parking has been pushed to the perimeter, so the streets feel safe and ‘owned’ by pedestrians rather than cars. Bin stores have been thoughtfully used in the front gardens to create buffer zones between the public footpath and the front doors, giving a humane gradation of public to private territory. The ‘back street’ has gardens and a pathway down the centre that has been fully landscaped, although the path takes a wavy course that stops the sense of a ‘back alley’ and gives a welcome curving foil to an otherwise rectilinear scheme.
Tireless work by the architects has kept the standard of workmanship up to a very high level. Social tenants get impressively high specification interiors – in both the end-of-terrace flats and the central terrace houses. Passivhaus detailing has nicely accommodated the mechanical ventilation Heat Recovery (MVHR) units in the interiors, and the services intakes have been intelligently controlled. Each dwelling has a range of providers’ services pre-wired, so that they can be connected on demand, without the need for a service providers’ to come in later and drill through vital vapour barrier lines.
Bringing the reduced energy consumption associated with Passivhaus to mass housing is a great achievement, and one that has taken a large amount of effort and care by the architects. This is an exemplary project.