Partners in the project line up at the site with a model and image of The Sill. Photo: Simon Williams

Plans for a multi-million pound visitor centre in a national park have been given the green light.

The £14.8m development in Northumberland will be the biggest ever national park construction project.

The Sill National Landscape Discovery Centre will replace the existing Once Brewed visitor centre. The youth hostel at the site will also be demolished.

Northumberland National Park Authority members approved the scheme after agreeing developers’ cost proposals.

The authority’s chief executive Tony Gates said: “I am delighted that we have taken the decision to proceed with this ambitious and innovative project.

“The Sill represents the largest scale initiative of its kind, in the history of not only Northumberland National Park Authority, but national parks across the UK. Its main purpose is to open up Northumberland national park and the surrounding areas to more people, helping them learn about and explore one of Britain’s finest landscapes.

“It will be open all year, offering a wide range of facilities including YHA accommodation, exhibition space, retail facilities and a cafe and restaurant. The Sill will, I believe, change how we as a national park authority does business and it will become a landmark asset for Northumberland and the North-East.”

Demolition of the existing centre and hostel will begin this month is expected to take about six weeks. Temporary national park visitor information and other facilities, including hot drinks, will be provided from Walltown from now, as well as the Twice Brewed Inn from the end of September.

Visitors to Twice Brewed will be able to access national park tourist information, along with local crafts and produce previously sold at Once Brewed.

The construction phase is expected to bring more than 100 new jobs to the region each year. When The Sill is fully operational from summer 2017, it is predicted to deliver substantial economic benefits to the region with around £5m of additional visitor spending every year. The Sill’s rural growth hub will support the development of rural enterprises, and the project will also offer a wide range of volunteering opportunities.

Northumberland national park chairman, Councillor Glen Sanderson said: “What we have witnessed today is one of the most remarkable and exciting decisions ever taken by our national park authority members. It’s a sign of their true vision for the future and means we can push on into construction of The Sill, the UK’s first dedicated national landscape discovery centre.

“None of this would have been possible without the support of our funding partners, including the Heritage Lottery Fund, North East Rural Growth Fund, Northumberland County Council and a range of philanthropic donors. We are extremely grateful to them all, and everyone who has, and continues to support us on this journey, as we move one step closer to realising The Sill dream.”

The Heritage Lottery Fund has provided £7.8m of the cash needed.

Caroline White, chief executive at lead partner YHA (England and Wales) said: “We are moving ever closer to the realisation of our dream to create a world class youth hostel and visitor centre in the heart of Northumberland. YHA began 85 years ago, so it is truly significant that the construction of The Sill begins in our anniversary year.

“It is testament to the hard work and dedication of the NNPA members and partners that this nationally significant project is now a reality.”

Construction company Sir Robert McAlpine has been awarded the contract to build the centre.