Related Companies has taken a 50% stake in a UK affordable housing company in the first deal of its kind.

The agreement to buy half of sector specialist Pocket marks the first time a US company has invested in the UK’s affordable housing market.

Pocket, which builds compact one-bedroom homes for first-time buyers at a discount of at least 20% to the open market, is aiming to complete 4,000 homes by 2023.

Stephen Ross, chairman and founder of Related, said: “Great cities must provide housing for the full range of its workforce, and Pocket provides a smart solution – well-designed, quality-built affordable housing in the parts of London where its knowledge workers want to live and work.”

Related last year created a partnership with Argent, one of the UK’s leading mixed-use regeneration specialists.

The latest deal makes Pocket and Argent Related strategically affiliated.

Pocket is currently working with Argent at King’s Cross and has worked with Argent Related on a bid to partner the London Borough of Barnet at Brent Cross South.

The companies said Pocket has doubled its pipeline since 2013 as demand for affordable homes increases.

Marc Vlessing, co-founder and chief executive of Pocket, said: “There is currently no end to the demand for our product.

“With Related’s support, we can deliver access to a wider range of for-sale and rental homes for this valuable audience.”

Vlessing said the company was encouraged by the UK government’s launch of its Starter Homes and London Help to Buy initiatives, alongside savings scheme Help to Buy ISA.