UK's best new homes revealed: a recyclable cork home, concrete Ghost House and subterranean London den up for House of the Year 2019

A 'recyclable home' made of cork set in the grounds of a Grade II-listed mill house in Berkshire is among projects in the running for RIBA's House of the Year 2019 award.

The twenty-strong longlist of recently completed homes or home extensions, all designed by architects in the UK, will be whittled down by the Royal Institute of Architects's expert panel with the overall winner to be revealed this autumn.

Environmental impact has been a key awards focus over the last few years, and this year is no different.

Chaired by architect John Pardey, the House of the Year jury considered four main categories when determining the longlist: architectural integrity; usability and context; delivery; and sustainability.

"It's all about houses on their own sites, in their own contexts, using lots of natural materials," says Pardey, "There are no modernist, white boxes or glass pavilions [on the longlist]."

Pardey recalls Kevin McCloud's narrative of last year's winning project, the off-grid Scottish hideaway, on Grand Designs: House of the Year and how the home had been tailored to its site: "[It has been] seamed into the tapestry of this place and it is so much the better for it."

Longlisted Cork House has been 'designed for dissembly' and can be constructed entirely by hand, with all its components reused or recycled. ​

RIBA's jury panel called the project "an incredible feat" and praised it for "what [it] could inspire within the architectural world."

Other projects to make the longlist include The Ghost House in Stratford-upon-Avon, built in the sunken garden of a now demolished country house.

Most of the concrete home is below ground level, lit by a series of different-sized courtyards.

Located on the Isle of Skye, the black-timbered Black House sits in a rocky depression near the water's edge.

The living space's fully-glazed end wall frames a spectacular view across the water to rugged hills beyond.

On a small plot, between two Georgian terraces, in a Kensington conservation area is 1A Earl's Court Square.

Once the site of two garages, it's now a two-bedroom house — with a living, kitchen and dining space on the ground-floor and two bedrooms and bathrooms on the lower-ground floor.

Of the six London projects longlisted this year, most are on very restricted sites. "Lots of backlands, gardens and single pockets," says Pardey.

"It becomes a kind of game: how you work with space and filter light through a house on a tiny site."

The House of the Year shortlist and winner will be revealed in the fifth series of Channel 4's Grand Designs: House of the Year — due to air later this year.

Also this week, London Bridge station and King's Cross Coal Drops Yard were declared among the UK's best new buildings at the RIBA National Awards.

The prestigious prizes celebrate architectural highlights from across the country, with the winners ranging in scale from striking landmarks like London’s Leadenhall Building, also known as the Cheesegrater, to under-the-radar gems like Lochside House, an eco-friendly home hidden in the West Highlands.