Building a future New London Architecture’s annual prize celebrates the best extensions in the capital. We reveal our top four

Studio Ben Allen has exploited the full potential of concrete in this multi-hued extension for a terraced property in Haringey (right). Supporting the structure are green-pigmented columns and beams, which are imprinted with ornate patterns, while the exterior wall is made from salmon-coloured concrete panels, inset with a matching window screen. Inside, a kitchen and two new bathrooms feature the same vibrant colour palette, along with vaulted louvre ceilings and flashes of gold. With so much creativity on show, it’s no surprise this inventive project was awarded first prize. studiobenallen.com