12 Modern Extensions That Anybody Planning a Project in 2027 Should See Before They Start the Process

A collaboration between Architecture for London and Hamish Vincent Design, this project sees echoes of the house's original arches. "We recreated these with a large arch in the rear extension facade," says Ben Ridley, founder of Architecture for London.

The soft curves, adds Daniel Jones, founder of Hamish Vincent Design, "[Create] an inviting and coherent home… that functions for its owner, whilst paying respect to its original bones."

Unwieldy site levels meant that Adam Draper (of Draper Studio) had to find a way to extend without blocking the neighbor's sun, and this is the result.

"By positioning the lowest point of the arch on the boundary at a height acceptable to the planners, the massing of the side return achieves volume without harming the neighbor's light," Adam says. "The arch of the side return was arrived at first, [then we] multiplied by the golden ratio to form the arch diameter of the adjacent extension."

Integrating landscaping into your extension can lead to a more interesting design, creating "a liminal space in which interior and exterior are no longer read as separate realms," says Iain Monteith, director of Loader Monteith, of this build. "Instead, they connect as one, extending and intertwining rather than merely negotiating an 'inside/outside,' relationship."

There's almost a monasticism to this extended space by Goldstein Heather. "We aimed to create a sense of domestic serenity and restfulness amid a bustling household, where relaxed connectivity is possible in all directions," says director Giles Heather. "That said, there was also an intention to create dramatic internal spaces, with an emphasis on diagonal, layered views."

Office S&M is known for its whimsical, fun projects, and That Purple House is no exception. "The original building felt dark, so we used color, curve, and pattern to bring a sense of delight to everyday life," says director Catrina Stewart. "On such a visible corner, it was also about creating a home that lifts the street."

Rather than use a new extension for a kitchen-diner, as many architects do, House of EM created a sunken seating area in this bright addition. "A sunken area in an open-plan space gives you a different experience — the alternative level and viewpoint create a sense of privacy and connection simultaneously," says director Emma Bodie. "The space can be calm and cozy for reading and enjoying the view, or a hub of chat, drinks, and music after dinner. The sunken level effortlessly creates a new dynamic, one that ties to the kitchen and dining spaces, but it has its own specific qualities."

In adding two new floors to this Georgian terrace in Belgravia, Studio DERA had to contend with a building with a history of changes. "The clients wanted the extension to be more than just a pastiche of the Georgian frontage," says Marcel Rahm. "This meant finding a simple but bold architectural language to unite the original elements with the new addition. Travertine, glass-reinforced concrete, glass panels, and greenery create an oasis linking past and present."

Part extension, part garden room, this addition, called The Gallery, "acts as a moment of transition, an architectural pause between the Edwardian house and the garden, yet it reads as a destination in its own right," says Laura Carrara-Cagni of Cagni Williams.

The Corten steel is softened with rounded glass and a wildflower roof. "It unfolds as a distinct, spatial experience, one that quietly mediates between inside and out while celebrating both," Laura adds.

Atelier Baulier added volume to this London home with a distinctive extension with a sawtooth roof. In contrast to the angular roofline, the color palette of the extension is soft, all plaster pink and sage green, with a line of green clay tiles acting as protective skirting at the base. A porthole window at the top is a nod to the curves of the interiors, and a point of difference from the outside.

This project by ConForm involved an infill extension on the first floor, housing a vaulted study. "This project is characterized by a series of layered thresholds," explains Ben Edgley, partner at ConForm. "Rather than disguising the new interventions, we allowed them to register clearly against the existing fabric — moments like the perforated steel ceiling above the living space."

Thanks to its walls of glass and mirrored soffit, this extension feels near-invisible when viewed from outside. "The idea of being immersed in the garden was a guiding principle for the design," says Dan Marks, founding director of MATA Architects.

For a project situated opposite a church, Neil Dusheiko, of his eponymous architecture studio, wanted the extension to feel rooted in its setting. "We drew on the surrounding architecture through proportion, rhythm, and materiality — using stone and timber to create something contemporary that still feels connected to the place," he says. "The timber roof of our new dining room recalls the church roof, linking the two spaces."