Architects Squire and Partners have been given the green light to restore and refurbish Brixton’s Toplin House, a disused Edwardian annexe to a former department store.

Lambeth Council has approved plans for a new breed of ‘department store’, comprising the practice’s own HQ, a restaurant and a gallery space inside the 1905 building. An adjoining disused fire station and stables will house three local creative businesses and a purpose-built facility for the local post office.

‘We wanted to create a hub where we could all feed off each other,’ said Tim Gledstone, a partner at the firm. ‘We’ve worked with these old buildings before and have seen how they can hold creative companies together, making a sort of club.’

Toplin House was built as an extension to the late 19th-century Bon Marché building – Britain’s first purpose-built department store, designed by local architects H Parsons & Rawlings.

Since Bon Marché stopped trading during the 1970s, Toplin House has accommodated the Refugee Council and, to this day, the post office – although the rest of the building has been empty since 2012.

‘As we’ve uncovered the building, we’ve discovered that it’s very ornate,’ said Gledstone. ‘We want to do as little as possible. We want to honour these poetic moments of decay.’

Squire and Partners plan to retain the structure’s original features, including its brickwork, parquet flooring, and rolling steel doors.

A rooftop social space and a landscaped courtyard will be among the new spaces created in the renovation.

The practice hopes to move into the space – simply named The Department Store – by Christmas 2016, moving away from its current King’s Cross base.

Squire and Partners are already getting involved in the local community. For this month’s London Design Festival, they are transforming Toplin House’s facade into an outdoor street gallery of local art.