The polycarbonate-lined Green House that architecture studio Hayhurst & Co slotted into a tight site in London has been named the RIBA's House of the Year for 2023.

Replacing an existing home in an alleyway in Tottenham, the plant and light-filled residence is modelled on a riad – a type of traditional Moroccan house built around a central courtyard.

It was hailed by the jury of this year's RIBA House of the Year prize as "a true oasis within the city".

"Green House, affectionately known as the 'Tottenham Riad', is a true oasis within the city," said jury chair Dido Milne, who is also director of Eton studio CSK Architects.

"It is both airy and cosy, bold yet respectful of its neighbours. Your eye is simultaneously drawn upwards to open sky and down and out across the living room to verdant greenery," she continued.

The House of the Year prize is awarded annually by the Royal Institute of British Architects (RIBA) to the best one-off, architect-designed house in the UK.

Milne added that Green House was also chosen as the 2023 winner for the clients' and studio's joint ambition to "deliver a truly sustainable home", which "is evident in all of the design decisions and detailing" despite a tight budget.

"Nowhere do you feel the site or budget was restricted," she explained. "It feels both luxurious, homely, deeply private and relaxing. It's an extraordinary ordinary house and a remarkable collaboration."

Designed for a growing family, Green House comprises five bedrooms arranged around a skylit atrium. With views of gardens and a roof terrace, it is designed to maximise their connection to the outside and access to nature.

Standout details include the sliding polycarbonate screens across the exterior, which enable the family to adjust both the levels of privacy and ventilation.

Its material palette includes exposed cross-laminated timber (CLT) walls, reclaimed concrete blocks and recycled cork rubber flooring, while air-source heat pumps and solar panels are used for energy.

Green House came out top in a longlist of 20, whittled down to a shortlist of six that included Cowshed by David Kohn Architects – the studio that won last year's RIBA House of the Year.

Hundred Acre Wood by Denizen Works, Made of Sand by Studio Weave, Middle Avenue by Rural Office and Saltmarsh House by Niall McLaughlin Architects were also shortlisted.

This year's jury was made up of Milne alongside the co-founder of the architecture studio Coppin Dockray Architects, Bev Dockray, the co-founder of the architecture studio Al-Jawad Pike, Jessam Al-Jawad, and the co-founder of design-led estate agent The Modern House, Albert Hill.

"Built on a very tight budget, this generous five-bedroom family home in the Clyde Circus Conservation Area of Tottenham is an inspiring example of what can be achieved with a creative and ambitious approach to design," read their citation.

Previous winners of the RIBA House of the Year award include House on the Hill by Alison Brooks Architects and Caring Wood by architects James Macdonald Wright and Niall Maxwell.

The photography is by Kilian O'Sullivan.