Derwent London has agreed a new 125-year headlease at 50 Baker Street, W1 with the freeholder, the Portman Estate.
The headlease follows a resolution to grant planning consent in August 2024 for a 236,000 square foot development on the site.
A contractor has been appointed under a pre-construction services agreement, with the main construction contract expected to be placed in the first half of 2026.
The new headlease brings all the existing buildings on the site under one agreement, with a ground rent set at 7.5% of gross income after completion.
The Portman Estate will add its ownership of 62-64 Baker Street, giving Derwent London full control of the island site.
The new building, designed by AHMM, will provide 204,000 square feet of office space, ground floor retail, and 17 private residential flats.
It is set to have an embodied carbon intensity of about 530 kgCO2e/sqm, below the GLA target.
Additionally, the project will use reconditioned concrete slabs, off-site manufacturing, and aims to reduce embodied carbon with new concrete mixes.
The building is targeting a 5-star NABERS UK rating, with core cooling and openable windows.
Paul Williams, CEO of Derwent London, said: “Building on the success at our 25 Baker Street project opposite and the strength of our longstanding partnership with The Portman Estate, I am delighted that we have agreed a new headlease at 50 Baker Street, enabling a start on site next year.
“The shortage of well-located Grade A space is becoming increasingly pronounced, particularly in Marylebone.
“That depth of demand, combined with the building’s quality and prime location, supports a compelling rental outlook which sets the stage for strong returns.”
Oliver Fenn-Smith, CEO of the Portman Estate, said: “We are proud to be working with Derwent London to deliver high-quality office, residential and retail space at 50 Baker Street – further enlivening Marylebone and our vision for the future of the Estate.
“Commencement of the development will mark an exciting milestone in our ongoing partnership with Derwent London following the success of 25 Baker Street and Loxton Walk.”
