A suburban housing development in Croydon has won the UK’s most prestigious architecture award, with judges praising its “inventive and site-specific response to a highly constrained plot”.

Lion Green Road in Coulsdon, comprising 157 homes across five distinctive 13-sided blocks, was named winner of the 2026 Stirling Prize by the Royal Institute of British Architects (RIBA).

Designed by Mary Duggan Architects and built with RUFF Architects, it combines affordable and private housing for Croydon Council.

The scheme replaces a former car park on a challenging, sloping site that varies in height by eight metres. RIBA president Chris Williamson praised the design as a “new approach to higher density development” creating “a new connection between the bustling Lion Green Road and a distinctive area of green parkland beyond”.

Only once before has the RIBA Stirling Prize ever been awarded to a council housing project, when Goldsmith Street in Norwich won in 2019, for its rows of low-energy brick terraces, designed by Mikhail Riches Architects with Cathy Hawley. This year’s winner puts a welcome spotlight back on housing design.

“At a time when we urgently need to deliver more homes,” says Chris, “Lion Green Road shows that density can be achieved without compromising the quality of the places we create. Through a consistent specification, with subtle variation in height and orientation, it offers housing at scale without uniformity.”

“We really pushed against the suburban model of terraces dominated by cars, with little front and back gardens,” says Mary. The original brief asked for 80 homes, but Mary proved she could fit 157 homes, distributed between five pavilion-like towers, retaining the mature trees and bluebell woodland on the site. The result feels like it has grown out of its woodland setting, with a public route that winds its way through the site, up to a historic railway embankment at the rear, and not a perimeter fence in sight.

Thanks to the “pinwheel” plan of the blocks, with flats radiating outwards from a central lift core, each home is dual aspect, maximising natural light, cross-ventilation and views. The flats all enjoy an inset loggia balcony, with a bulge at the base of the balustrades to accommodate plant pots, while cuts in the form (to preserve historic views) create some with larger roof terraces.

In the interests of efficiency, the five towers all have the same star-shaped plan, but each is subtly rotated to reduce direct overlooking between neighbouring homes, enabling the buildings to stand close together without sacrificing privacy. Half of the flats are private rental, in two towers, while half are affordable, in three blocks retained by the council, rented at local housing allowance rates.

The RIBA judges describe the project as a “new kind of garden neighbourhood”. The space between the blocks feels consciously planned, rather than a leftover afterthought, designed with landscape architecture practice Planit-IE to include a sensory garden, allotment plots and play areas.

The project was funded by Croydon Council as a public asset. The recent change in building regulations meant the project was more challenging than usual.

Buildings are assessed across a range of criteria, including design vision, innovation, sustainability, functionality, and the ability to delight users and visitors.