I’M sitting in an oversized garden shed drinking very good beer, the soft Merseyside tones of Stuart McCarthy explaining why a teacher from the Wirral lives on a remote Scottish island. Outside it’s a normal Eigg day: one moment brilliant sunshine, the next freezing hail.

“Every day is different,” says McCarthy. “I never know how that day will pan out, but with that strangely is a sense of control.”

What he doesn’t mean is push-button control over air conditioning, or knowing when he’ll finish work, or that he can buy what he likes when he wants it, or that he’ll get home warm and dry. It’s control over what he does, when he works; how he lives.

He came here three years ago with Eigg-born wife Tamsin. He set up the Laig Bay Brewing Company in the shed behind the home of brewing partner Gabe McVarish, above Galmisdale to the south. The brewery would fit in a domestic kitchen and McCarthy admits it was quite amateurish – until a supermarket ordered 2,500 bottles. Suddenly they had to get their act together.

Eigg is five miles long and three-and-a-half wide. It’s an hour by ferry from Mallaig. Traditionally the island lived off agriculture, and 20 years ago there were 60-odd people here. Now the population exceeds 100.

The island also hosts an environmental activity centre, an adventure tourism company, an organic market-gardener, basket-makers, textile artists, a raft of musicians, a record label and studio, a catering firm, yoga retreats, a photographer, a music festival, an arts project manager, a sail-charter business, a tree nursery, writers, a film-maker, a massage therapist ...

The Highlands is, in some areas, beginning to slowly turn around the population decline of the last 200 years. The Lochaber, Skye and Wester Ross area, which includes Eigg, recorded growth of around six per cent in the 12 years from 2001. But Eigg’s population has grown by 66 per cent in less than two decades. Some social alchemy has turned the pitchstone and basalt of the island’s uncompromising bedrock into what seems like fertile soil for newcomers. Who has come here, and why?

The change started with the residents’ buy-out of Eigg, which began 20 years ago this month. After years of decline under owner Keith Schellenberg, the island ended up on the market. Islanders launched an audacious bid and helped by thousands of small donations and one huge anonymous one of £750,000, they raised the £1.5 million required, and took ownership in 1997.

Two decades later the material benefits are numerous. The environment is properly managed thanks to the Scottish Wildlife Trust’s role in the Isle of Eigg Heritage Trust (IEHT) which ran the buyout and now runs the estate. There are secure tenancies, a shared home-ownership scheme, housing association properties, a new pier, shops and cafe, an all-green electricity system and, vitally, a good broadband link. But the sum seems to add up to much more than the parts: the island has developed an air of can-do, the feeling of a place with a future.

McCarthy taught in Liverpool and Manchester, then he and Tamsin worked in Kathmandu for four years. They couldn’t face cities again, and came to Eigg. Not much money is needed here – another couple say making £20,000 a year between them is fine – but, as elsewhere in the Highlands, you must wear different hats. McCarthy runs the hostel; McVarish plays the fiddle for folk group Daimh. They have been brewing for two years, and hope to make a profit soon.

McCarthy explains what lies behind the success of his brewing venture. “Ownership, plus the sense of self-reliance that has always existed on the island, is a good combination,” he says. “What the trust does – and has enabled people to do – is a reflection of their success, coming from nothing and no money. It wasn’t just a buyout; they have sustained 20 years of facilitating people to live how they want and grasp things for themselves rather than being told what to do.”

I finish my beer and head out into light hail to meet Eddie Scott to get a tour of the electricity system’s control centre, near the heart of the island. Wind, water and solar power mean the island can depend on renewables in almost all weathers.

Scott shows me rows of computerised rectifiers that sort out the sources of power and feed it to banks of batteries to produce a steady supply. The technology is good, but it’s the way it’s been done which tells you most about Eigg.

The cost of a cable from the mainland would have been £7 million. “No chance,” says Scott.

Instead this system was built for a quarter of that, supported by EU grants. Local people were trained to run it. “We’re not paying an engineer to come in every so often and adjust it,” he says. “We can fine-tune the system as often as we want.” It means they get the maximum output from the renewables. They don’t pay for a service but use their own time, and pay themselves.

One of the first things visitors see when they come off the ferry is Eigg Adventures. Laraine and Owain Wyn-Jones offer bicycle and canoe hire, and archery lessons. Over tea in the noisy cafe-pub-restaurant next to their shop at the pier, Owain says he was on the support boat for a marathon sea swim in 2013 when he first came here.

He came back with Laraine and they both fell for the hills and shoreline, the colours and light. Then Owain was offered short-term work on the island. The couple, in their 30s, had vowed a few years earlier as Owain recovered from a stroke to live to the full. The owner of the island’s bike hire business sold it to them, and they got an IEHT house. Their sociability and dynamism won them friends. “People here were looking out for us – they wanted us to stay,” says Owain.

The couple have expanded the business and become bike mechanics. A new venture is camping pods, adding to the island’s growing holiday accommodation stock. Community ownership, the couple say, has brought Eigg onto its front foot. “What’s happened since the buyout means things are in place to bring tourists in. People have become focused on them, and that culture has grown,” says Laraine.

I’m a tourist, of course, here to enjoy the scenery, so, rain or shine, I am cycling and tramping the island. One sunlit, wind-whipped afternoon I climb the hill above Cleadale on the north side and enjoy an astonishing panorama of snow-spattered hills from Skye to Glen Shiel to Lochaber, down into Argyll, then around sparkling sea and lower islands to Rum.

I’m staying at Laig Farm in Cleadale, where George Carr and Saira Renny raise sheep. Carr is Eigg-born, Renny arrived nine years ago. While I’m here a rare late deep snow blows in, and I build a snowman on the beach. Carr and Renny spend the day indoors worrying: if they go out the ewes will follow them and lose their lambs when they need milk most.

But the next morning is bright and breezy, the burns roaring with snowmelt. Just two lambs died. Renny is in the field, smiling not just with relief but, she says, with the pleasure of being here: the view west is stunning, over the marbled sands of Laig Beach to the crusty Rum Cuillin, pure scenic opera, soaring and swooping across the narrow sound.

Alistair Maclean wrote his tender, crazy remembrance of crofting life, Night Falls on Ardnamurchan, on the mainland at Sanna, just 15 miles away. He hated the harshness of his parents’ life – it made him “shake with rage”, he wrote.

But he added: “And yet and yet – the great ‘and yet’ which in Ardnamurchan so often betrays one out of anger and into wonder: our shoreline is never less than beautiful, and in places goes as far beyond that as your language and your nerve-ends will carry you. When supper is rough and rainy miles away or when the cold so grips that your marrow plummets in your bones, you have that for a kind of consolation.”

Maclean’s work was a loving farewell, the story of his brave father who could not give up the beautiful tumble of water, light, rock and air. The Macleans waited for electricity to be given in a disappearing community with a shrinking sense of purpose. Here people such as McCarthy, the Wyn-Joneses and others I will meet also know and love the wild outland, but now there is a way to make a life in it.

Mobile phones don’t work on Eigg much, and I want to meet Norah Barnes and Bob Wallace. They have 12 years’ experience here after buying the island’s big house. Have they made it work?

I email and get no reply, so I turn up on their doorstep. I’m wary of calling unannounced at a grand pile, but with wellies, old jumpers and a warm smile, Barnes is the least grand person you could imagine. She invites me in and feeds me tea and biscuits, frets about the untidiness, is kind and funny, and is pleased with the workmanlike repairs done since they bought the place.

The house, formerly the Schellenberg residence, was a big liability for the IEHT. Built in 1927, it had a leaking flat roof, dry rot, shaky plumbing and a huge heating bill.

Elsewhere it might have been sold to a hotelier to sink a million into renovation, and then run hard to turn a profit. The IEHT wanted something different.

Barnes and Wallace had studied human ecology – the connection between people and their environments – and were living on a boat, looking for a place to put ideas into practice, when the idea of the house came up. To buy it they had to have a business plan showing the whole island would benefit.

“Our proposal was to do it up low-key, small-scale, using volunteers and our own labour and in an environmentally friendly way, recycling so it wouldn’t cost so much,” says Barnes.

For Barnes, like McCarthy and the Wyn-Joneses, the buyout was important. “There seemed to be a different lifestyle here, and people who were not afraid to make a stand about things, a bit of idealism – that appealed to us.”

When I ask what they paid for the property, with family living quarters and seven guest bedrooms, Barnes says it’s confidential. I suspect the answer is “not very much”.

The couple run it as the Earth Connections Sustainability Centre, staging courses in environmentally friendly living and yoga. Barnes gives me the tour: there’s a big room with a slice-of-log table, a bigger hall for yoga and film shows, and bedrooms furnished to fit the place’s vintage. There’s a patch of damp, a bathroom that needs work and a room filled with woodwork machinery. Outside are a rusty collection of bikes, greenhouses and a sun-trap where Barnes proudly shows off two fig trees.

Some might view the couple’s business plan as not very businesslike (the first thing they did was secure the roof; the next was to plant an orchard). Barnes is unsure of the figures but reckons they had fewer than 100 people on their courses last year. They bought timber milling equipment so trees from the gardens, felled because they were dangerous, could become planks for repairs, seasoning them in stacks in the main hall.

The determination to stay and Barnes’s commitment to Eigg remain strong, but it’s clearly not all gold. The immensity of the house and repairs can weigh heavily, and money is a concern. Barnes’s older sons are now boarders in Mallaig, and she sees them only once a fortnight in winter.

Others admit it isn’t always easy. Like many Highland places, there’s a lot of drinking, with a can or maybe two consumed waiting for the lunchtime ferry. Everyone mentions isolation and the dark winter. There are few escapes.

That evening I talk to arts project manager Lucy Conway, 54, sipping wine and gazing out at that astonishing view of Rum from Cleadale, where she moved with her husband Scott 12 years ago.

“You have to have a lot of personal resource,” she says. “If there’s a chink of vulnerability – financially, in mental fortitude or physical illness – it can be really hard. People talk about each other all the time. It’d be odd if they didn’t because it’s a small community, and if you don’t talk about what pisses you off it festers. But if you are feeling a bit fragile – ‘I don’t like myself today’ – it can be hard.”

Her original ambition was to build an arts “hub” – a work centre where creative types could exchange ideas. Now she has stepped back, but hopes to take over part of the island’s old doctor’s surgery for a smaller project, to get “proof of demand”. “It feels more possible here because you can see how you can steer things,” she says. “There’s not one person or company or family you have to persuade – the community has control.”

That word, control, keeps cropping up. John Chester, the island’s retired Scottish Wildlife Trust ranger, tells me that under Schellenberg fences were broken and livestock trampled on sites of special scientific interest. Dense conifers blanketed a swathe of the island.

After the buyout fences were fixed. Hazel scrub moved in, with primrose, bluebells and wild garlic. Within a year eroded slopes started to recover. The conifers were part-cleared, letting native trees flourish, and the woods are managed for fuel and wildlife.

“Before the buyout,” says Chester, “the thing that held everyone up was we had no control over the land. Now we do.”

The northerly weather that has chilled the week is over. White gulls are picked out in sunlight against the dark regiment of rain riding in from the south. There’s time for a last walk over the cliffs above Cleadale. I see ravens nesting on the Finger of God, a dramatic pinnacle, then come down the hill and along the road to the home of Maggie Fyffe. She is secretary of the IEHT and the figurehead of community ownership. A Lancashirewoman who once hit the hippie trail to Pakistan in a camper van, she and husband Wes were persuaded by Schellenberg 40 years ago to come to Eigg. They fell out with him and she led the islanders’ charge to take control.

What motivated them was neglect, and obduracy from Schellenberg: leases were not issued, improvement projects foundered, there was no electricity system, the natural beauty was tarnished by neglect. Eigg’s was one of the first Scottish buyouts and fired the imagination of land reformers. But Fyffe points out it was blessed in being a self-contained community: unlike some other estate buyouts the population lives within the community-owned area, and depends on the pier and power system. Everyone could see the advantages.

The motivation for such a huge task has to be strong, too. Fyffe says the buyout would have been unlikely if things weren’t quite so bad.

“It would have all been very different here if Schellenberg had given people leases. People were asking for leases for workshop spaces and houses and he wouldn’t do it,” she says. “We reached a crisis point – that was what tipped it over.”

What Fyffe says chimes oddly with what I hear at the annual conference of Scottish Land and Estates (SLE) two weeks later in Edinburgh, where SLE’s landowner members are courted by bankers, upmarket lawyers and property agents.

The possibility of communities forcing buyouts has increased with the new Land Reform Act, the result of a movement in part started in Eigg. There’s a pot of £10 million a year to aid buyouts. Landowners are worried, and their leaders tell them to engage with communities, sell off small tracts of land to local groups, play nice: don’t do the things that forced the hand of the Eigg folk.

The Eigg buyout shows what’s possible. It’s not a template but it shows what ownership can achieve.

As Fyffe says, “We have created an environment where people feel happy to come and develop things, do things, for themselves.”