A £20 MILLION museum telling the story of boats and boat building in the Lake District is to open its doors this spring.

The new Windermere Jetty Museum of Boats, Steam and Stories is one of the first pieces of contemporary architecture to be built on the lake shore for more than 50 years.

The copper-clad cluster of seven buildings is to house an "internationally significant" collection of 40 vessels, from Victorian steam launches to record-breaking speedboats from the 1980s.

Beatrix Potter's tarn boat which she used to sketch in will be on display, as well as hydroplanes, SL Dolly, the oldest mechanically powered boat in the world, and the 1922 Canfly, powered by a seven-litre Rolls-Royce aero engine.

Windermere Jetty has been constructed on the site of the former Windermere Steamboat Museum, founded in 1977 by steam enthusiast George Pattinson.

Principally financed by the Heritage Lottery Fund, the new visitor attraction has been developed by award-winning architects Carmody Groarke and Lakeland Arts, which also operates Blackwell, the Arts and Crafts House at Bowness, and Kendal's Abbot Hall Art Gallery and the Museum of Lakeland Life and Industry.

The museum's walls and roofs are clad in oxidised copper, which will weather over time. At its heart is the Boathouse, where vessels can be seen on the water. Sculptural silhouettes will frame the lake views, and a series of new jetties will allow visitors to sail on the 1902 Osprey, a full restored Edwardian steam launch, as well as arrive and depart via Windermere Lake Cruises.

There is a lakeside cafe and visitors will also be able to view the Sir John Fisher Foundation Conservation Workshop, where a team of skilled boat builders will be at work, restoring boats that would otherwise be lost to history, as well as running apprentice and volunteer programmes to train the next generation.

The museum will open with five themed displays - Just Visiting, Life of Luxury, War & Innovation, Spirit of Adventure and Speed - telling the stories of who built and owned the vessels and how they were used on Windermere.

Lakeland Arts took over the old museum in 2007 after it had closed the previous year. Eleven of the boats were allocated to Lakeland Arts by HM Government’s Acceptance in Lieu Scheme and the rest of the historic boats and a wealth of other objects were transferred from the Windermere Nautical Trust.

Gordon Watson, chief executive of Lakeland Arts, said: "It is thanks to the support of local people and the many organisations that have funded Windermere Jetty that we will be opening the museum in spring 2019. "

Andy Groarke, director of Carmody Groarke, said the architects had been "enormously proud" to be involved since being selected in a RIBA competition in 2011. "We are now very much looking forward to the Windermere Jetty opening its doors and welcoming visitors to experience and enjoy such a fascinating collection in such an inspiring location," he said.

The practice's past projects include the permanent memorial to the July 7 London bombings, and current schemes include an extension of Manchester's Museum of Science and Industry.

The Heritage Lottery Fund gave more than £13 million and the new museum was also funded by the Department for Digital, Culture, Media and Sport's Northern Cultural Regeneration Fund, the Regional Growth Fund, the Rural Development Programme for England, the Sir John Fisher Foundation, Garfield Weston Foundation, the Wolfson Foundation, South Lakeland District Council, the Headley Trust, Foyle Foundation, Windermere Lake Cruises, J P Getty Jnr Charitable Trust and other trusts, companies and individuals.

Opening dates will be announced in early 2019. For more, see www.windermerejetty.org