Squatters have moved in next door. 195 Mare Street, a Grade II* listed Georgian villa built in 1699, is the second oldest surviving house in Hackney. It’s been derelict for years: windows boarded up, front garden overgrown. Until, that is, one evening last week, when I saw people passing bags and boxes over the gate. The next morning, some sheets of A4 paper had been posted to the railings.

One of them was a standard legal notice that can be downloaded from the website of the Advisory Service for Squatters. The recent lawmaking the squatting of residential properties a criminal offence doesn’t apply to commercial buildings; 195 Mare Street hasn’t been a family home since 1845. Another of the sheets was a document showing that the squatters have set up an electricity account in their names. A third notice explains why they are there: to take care of a historic building; to protest against the new anti-squatting legislation; because they have nowhere else to go.

A few days later another sign was posted, an invitation to a general meeting. I went along. The grass had been cut and bags of debris were sitting on the porch. Inside, the building is a huge, beautiful mess. The Georgian foyer, with its sculpted doorways, gives on to a cavernous theatre annexe, built in the 1930s, the walls covered in bright murals.

The current squatters aren’t the first. For its first 150 years the house was a grand family home, one of many on Mare Street. From 1860 to 1913 it housed the Elizabeth Fry Institute for Reformation of Women Prisoners – there’s a commemorative plaque on the gatepost. It then became a working men’s club, the Lansdowne Liberal and Radical Club (later the New Lansdowne Social Club), which closed down in 2003. Since then the deeds have passed through various developers’ hands. Permission was granted in 2006 for the building to be partly demolished and converted into a restaurant and luxury flats, but nothing came of it. In 2009, squatters moved in and fixed the place up. They gave free workshops on bicycle repair, clowning and welding; staged benefits, cabarets and gigs; hosted political meetings and the London Freeschool. A year later they were evicted when a bank repossessed the building. Recently it has been bought yet again – there is a large sign in the garden, ‘Currell Commercial Property: Sold’– but the buyers are unknown, and so are their plans.

There were forty or so people at the meeting, plus a few dogs. We sat in a circle on the floor, drinking tea. The nine new residents introduced themselves, and explained that they intended to open up the ground floor, where we were sitting, as a community centre once the cleaning and wiring were done. What would we like to see there, they wanted to know, what does the community need? Among the suggestions were spaces for music, dance and film projects; a community garden; workshops on financial literacy; a citizens’ advice service to handle the overflow from the council; meetings to organise around the human costs of anti-squatting legislation; a free vegetarian kitchen. Someone asked what their plans are if they’re served with a court order. Why be so ambitious when there’s no guarantee they’ll still be here in two weeks’ time? ‘We’re optimistic,’ the woman running the meeting answered. ‘We’re open.’

The optimism is cheering, but the pessimism is understandable. It’s estimated that nearly 25,000 properties in London have been empty for longer than six months; homelessness is on the rise and there’s a shortage of affordable housing. Squatters with the energy and knowhow to deal with the red tape and police harassment are doing their bit to narrow the gap between housing supply and demand – and, in some cases, to save historic buildings from neglect. But since the criminalisation of residential squatting in September 2012, properties like 195 Mare Street are their only legal option. And it may not last: in the last session of Parliament, 24 MPs put their names to an early day motion to criminalise commercial squatting.