You may not have heard of Cove Park.

You may be forgiven for not ever having seen it, hidden as it is on the western side of Argyll and Bute's Rosneath peninsula, amid Loch Long, the Firth Of Clyde and the Gareloch. However, Cove Park is known to many artists, writers, craft-makers, thinkers, companies and creators who have stayed there, worked there and collaborated there in its reasonably short history. This 50-acre place, 40 miles west of Glasgow, is a one-off, and one of the most sought after and popular artist residencies in the UK.

Director Julian Forrester says that in the 14 years of its life, Cove Park has been home to 1400 artists. They come for the peace, the solitude and the concentrated time, free of distractions, that the Park, founded by Eileen and Peter Jacobs in 1999, provides.

Run as a charity, it has 10 accommodation units on grounds that slope down to Loch Long. It is in these units that artists of all kinds can live, work, plan and also, crucially, collaborate. Some of these units are big enough for two people, others are single pods that overlook the dramatic landscape across the water. They are private and discreet. There are studios and a workshop and - this is where we get to the crux of its looming redevelopment plans - there is also a main building for public and private events, with a simple kitchen and dining area.

Every summer, from May to September, Cove Park runs its main residency programme, both for individuals and groups of collaborating artists. The residents are paid £400 a week and are decided by open application every year, with groups coming by invitation only. This work is supported by Creative Scotland and the Jerwood Charitable Foundation, as well as other trusts and foundations. During the winter, from October to April, artists can pay for their own residencies - a valuable source of income for the charity.

Margaret Atwood stayed here and said the place was "wonderful and energising". Gideon Ofrat, curator, believes it is "paradise". Louise Welsh, Zoe Strachan, Christos Tsiolkas (author of The Slap) and Jennie Erdal have lived and worked here too, as have Roderick Buchanan, Henry Coombes, Ron Butlin, Luke Fowler and the National Theatre of Scotland.

If the Park was an artist, its CV would be outstanding: Booker Prize winners (Atwood), Costa winners (Jo Shapcott), Turner Prize winners (Elizabeth Price, Simon Starling), Henry Moore fellows, Venice Biennale artists, Jerwood Prize winners, and award-winning theatrical directors and producers have all stayed and worked on this plot of land.

About 65% of its residents over the years have not been Scotland-based: Kristin Linklater, the voice coach for actors such as Donald Sutherland and Sigourney Weaver, gives annual masterclasses for poets. Electric Hotel, conceived by David Rosenberg and Frauke Requardt for Sadler's Wells, was worked on here. Visual artist Simon Starling developed his Autoxylopyrocycloboros here, before it was shown at the GI festival in 2010 and around the world. Tom Morris, artistic director of the Bristol Old Vic, has said: "Every serious theatre maker in Britain will want to work at Cove Park."

Change is afoot: £1.3million of change, in fact, and the most significant shake-up of the centre since it was established in 1999. In short, the main building is falling apart.

The £1.3m needed to build a new public building will realise the vision of architects Cameron Webster as well as those of Forrester and Cove Park's board, led by Seona Reid, former director of the Glasgow School Of Art.

The new building, while hardly ostentatious, will be bigger and more flexible. The present public space is only big enough for one thing to be going on at a time; the new centre, slightly further down the hill towards the loch, will allow for artists' work as well as education work. It will also have two more accommodation units.

The new centre will also allow Cove Park to be open throughout the year - it effectively closes between December and February because the main building is too "inhospitable". Right now, of the money that needs to be raised, £800,000 has been pledged or is in the bank. In January, it received £621,000 from Creative Scotland.

"We have the remaining balance to go," Forrester says. "We have three outstanding bids to trusts, we hope we will find some individual donations, and then later... I hate to use the words "crowd funding" but we will ask for smaller donations. We have eight or nine months to find it to be able to break ground in early 2015. It will be a long process, but I am confident we will get it."

The current public building, the first you see when you arrive at the site, is essentially one large room. "The real problem is that it is falling down," says Forrester. "In fact, right now we are using black tape to stop this lovely Scottish summer from pouring in. It is just not terribly suited for what we want to do, and it is too small.

"If we want to do anything other than one thing at a time, there's a problem. Whatever is going on in the space has to stop so we can do something else, such as an education programme, which we love to do. The extra two units of accommodation will take us up to 12, and the two proper studios will take us up to five. It is a major development for us."

Work, however, is not stopping at Cove Park. There is full summer programme for 2014. Following a research residency in 2013, the Glasgow-based artist Alex Frost has been commissioned by Cove Park to develop a new temporary work for its site in 2014.

The commission is part of Generation, the nationwide celebration of 25 years of contemporary art in Scotland. The work will be on site from June 21 and a programme of related open days and events will take place during the summer and early autumn. Michael Pedersen, Kate Tough and Nicola White will be taking part in writer's residencies.

Forrester hopes, too, that some artists who have stayed and worked at Cove Park may be able to contribute to the fund raising. But he says the matter is delicate and of great importance to himself and the charity - Cove Park, he says, exists to support artists, not the other way around. He does not want to compromise that relationship.

"We cannot expect artists to just support us (with money)," he says. "It is something we have to be careful with. So we are saying: only give something if you want to. If we do do something, it will be at the end of the summer. We want our relationship between ourselves and the artists to be unadulterated."

For more information on Cove Park's fundraising, see www.covepark.org. Its charity name is Cove Park, registration number: SC029530 and email is: information@coverpark.org