Not so many years ago, arriving on a Friday night at Bridewell Street in the centre of Bristol (better known as The Bridewell) might have meant a night in the cells. Until 2005, this cluster of Grade II-listed buildings housed a police headquarters, police station and law courts, as well as a fire station. Since then it has been many things, including a graffiti gallery and a circus space – I have dim memories of coming to a rave here, once – and now it’s home to the Bristol Wing, a new boutique hostel with a social conscience.

Passing through a doorway engraved with the words Bristol Police Headquarters, my partner and I found ourselves in a stately 1920s foyer with forest-green walls, a black-and-white tiled floor and a restored cage lift: it’s a bit like a scene from Wes Anderson’s The Grand Budapest Hotel. It would be tempting to describe this as a sanctuary from the streets outside, but that would miss the point. Along with its green credentials (wood-fibre insulation, solar panels and bird boxes on the roof), this hostel, opened in January 2018, provides nine single bedrooms for young homeless people every night, as well as one-to-one support, subsidised by fees from the commercial rooms and dorms.

The need for such a service is desperately apparent. As it gets more popular, and gentrified, Bristol has experienced a huge rise in homelessness: 128% over the past three years. As we walked through the centre of town, it seemed that every shop doorway sheltered a figure in a sleeping bag, the fallout of austerity and a street drug crisis.

Shining lights: an eco-break in Northumberland's dark-sky country Read more

Inside Bristol Wing, however, the reception/kitchen/hangout space had an air of almost-scholarly calm (no stag or hen parties are allowed), with people sitting reading books and quietly conversing. A group of Spaniards, Germans and Finns attending a circus skills course were discussing what dogs and cats say in European languages (Finnish dogs say “hau hau”, apparently); it’s a conversation I must have heard in hostels on five continents. The convivial atmosphere, with help-yourself tea and coffee, is conducive to breaking down barriers between paying guests and those without a home; across the foyer, a snug with armchairs, sofas and bookshelves is another encouragement towards social intermingling. Other community-minded touches include a resident chaplain, available every Wednesday morning, and a free weekly feast at which guests can volunteer to cook or simply take a seat and get to know their neighbours.

Facebook Twitter Pinterest The hostel’s communal ‘hangout’ space

Our first-floor bedroom had stylish Anglepoise lamps and an enormous square bed, plus an en suite shower room. The window (thermally efficient, according to the blurb), overlooked the spacious yard of the old fire station next door, which now houses a performance space, community radio station Ujima and the Creative Youth Network, which offers support services for young people. On the evening we arrived, the station was hosting a club night – happily, the windows insulate sound just as well as temperature – and a couple of costumed fire jugglers were swinging flaming orbs outside, which the building’s former owners might have taken as a professional challenge.

Facebook Twitter Pinterest Family room at the hostel

This repurposed municipal complex is the perfect place from which to explore the city’s green and alternative side. Bristol, which regularly appears on lists of the UK’s best places to live, is also one of its most polluted, with levels of nitrogen dioxide almost twice the legal limit; a recent study claimed that pollution kills five people a week. Congested it may be, but the city is fighting back. Visitors arriving here by coach can’t fail to notice the Extinction Rebellion artworks lining the M32, and pressure from environmental campaigners – not least the School Strike for Climate movement – has led to two recent victories: a vote to ban diesel vehicles from the centre from 2021, and the creation of a Citizens’ Climate Assembly.

Ashley Vale, in the neighbourhood of St Werburghs, is the catalyst for much of this, and a good port of call if you want to escape the congestion. This community of eco-friendly self-builds, surrounded by allotments and smallholdings, is only half an hour’s walk from the hostel but feels more like the countryside, with the grunts of pigs (and the smell of manure) drifting from the free city farm, and an indoor climbing centre in a deconsecrated church. It’s worth stopping in St Werburghs to eat: The Cauldron serves ethically and locally sourced food cooked over open coals and in a wood-fired oven (mains from £14) and is a great place for brunch (from £6). The Miner’s Arms up the road is one of the friendliest pubs in Bristol.

Facebook Twitter Pinterest The Cauldron restaurant

Not far away, richly graffitied Stokes Croft – scene of a riot in 2011 over plans to open a Tesco Express – is still the frontline between gentrification and alternative culture, with an ongoing battle to save the artists’ studios and community space of Hamilton House from developers. A neighbourhood gem is the Cube Cinema, an independent “microplex” behind King Square, with £5 film tickets (free for asylum seekers), “feral trade” coffee brought by ship from Central America, and a radical, eclectic programme of music, performance and storytelling. Having fought – and won – its own battle against eviction in 2014 (a community fundraising campaign enabled the purchase of the building) it is a heartening example of Bristol’s independent spirit.

From Bristol Wing we spent our weekend exploring these alternative corners of town, a stone’s throw – but a world away – from the commercialism of the city centre. We left on the Sunday morning, well-slept, our £3.95 continental breakfasts inside us. The doors to the former police headquarters swung shut on a project that is doing its part towards making the city, and the world, a slightly kinder place.

• Accommodation at The Bristol Wing was provided by Sawday’s, dorm beds from £18 a night, doubles from £50 a night

Nick Hunt is author of The Parakeeting of London: An Adventure in Gonzo Ornithology (Paradise Road, £10)

Looking for a holiday with a difference? Browse Guardian Holidays to see a range of fantastic trips