Tucked away at the edge of Downing College's East Lodge Garden in Cambridge, sitting alongside the manicured lawns and neoclassical architecture, is an unassuming Edwardian stable building. Formerly serving as a maintenance shed and largely forgotten, the modest stables were reopened this week with an altogether more pivotal role on campus as the Heong Gallery, a new public space dedicated to modern and contemporary art.

Conceived as an inviting threshold between the hustle and bustle of Cambridge's Regent Street and the centre of the College grounds, the Heong Gallery, according to Downing College master, Professor Geoffrey Grimmett, is a way of integrating Downing into the local community. 'The Art Gallery is something different because it doesn't just look in, it looks out,' says Grimmett. 'This is a public art gallery with free access so it's not only something that is exciting for the student body and the fellowship, but it's also going to bring the community in who wouldn't necessarily be drawn to Cambridge colleges.'

Architecture practice Caruso St John was tasked with the transformation, which included the creation of a new tree-dotted courtyard space and the entranceway to Parker House, a former office building adjacent to the stables, which was recently refurbished to accommodate 78 smartly-appointed graduate student rooms and eight common rooms.

Inspired by Kettle's Yard – the nearby Cambridge University-owned art gallery which was formerly the home of art collector Jim Ede and his wife Helen – Adam Caruso was intent on creating a modest gallery space within Downing's majestic context. 'The transformation of Jim Ede's old house illustrates the possibility of a modest structure coexisting with the grand architecture of the colleges and housing a space where study, conversation and art naturally come together. This modesty and feeling of easy access is about an intimacy in scale, and is also about building in a certain way.'

Inside the gallery, Caruso achieves this sense of domesticity through a clever selection of materials and finishes; natural oak window frames, doors and furniture are complemented by a floor of dark, encaustic tiles made in Ironbridge. Two generous glazed screens in the foyer, which feels much like a living room with its original cast iron fireplace, look out across the courtyard to the east and across the East Lodge Garden to the west. From here a double doorway leads visitors into the main gallery space, where the ceiling height doubles, and a single long roof light cut into the stable's pitched roof draws the eye upwards.

Fittingly, late 1950s and early 60s paintings taken from the personal collection of Sir Alan Bowness – including works by Patrick Heron, Peter Lanyon, William Scott and Allen Jones – are currently on show, while plans underway for an Ai Weiwei exhibition and a show of contemporary African Art in the coming year.