Kenwood House reopens on Thursday following a £5.95 million revamp to restore the world renowned Robert Adam interiors to their former glory and make it more welcoming for visitors.

During the 19-month closure the original paint scheme and furniture designed by the architect for the first Earl of Mansfield were re-instated in the entrance hall, antechamber and library.

Rope barriers have been removed, paintings re-hung and re-lit, and a children’s trail created to make the 18th Century stately home on Hampstead Heath more accessible and enjoyable.

“The most important bit has been fixing the roof and lead gutters,” said Michael Murray-Fennell of Kenwood’s custodians English Heritage.

“There comes a point in every house’s history when time and the elements take their toll and major repairs need to be done.

“We’ve also restored the three Adams rooms to his original decorative scheme and in the rooms on the south front we’ve honoured the wish of Lord Iveagh who bequeathed the house to the nation, to recreate the atmosphere of an 18th Century gentleman’s home.

“These rooms which felt a bit like a municipal gallery with poor lighting and nowhere to sit are now more comfortable and inviting with an open fire, leather chairs and sofas to sit on, better interpretation and no rope barriers.

“Visitors are encouraged to sit down, put their feet up and enjoy the surroundings.”

Senior Curator, Dr Susan Jenkins, whose voice can be heard on a free app detailing Kenwood’s rooms and 63 artworks, said paint analysis revealed the previous decoration of the Adam rooms carried out in the 1960s was inaccurate.

“We took a tiny cross section through the layers of paint back to the plaster and analysis by date showed the first layer in the library wasn’t gilded but white with a layer of dirt on top so time had elapsed while it was on the wall. We pulled up the parquet to reveal the original 18th century wooden floor and an inventory from 1796 told us what furniture was in the room. We bought back items sold off in 1922 when the Mansfields left Kenwood, have an original desk on loan from the V&A abd we made replicas of other items.

“I believe the library is now the most important Adam interior in the world because it has so much that’s original and was a scheme we know he was incredibly proud of.”

Dr Jenkins says the restoration presents the house in a more domestic light, allowing visitors to enjoy it “as if they were a guest of Lord Mansfield”.

As part of the Heritage Lottery Fund grant, a team of volunteers has been recruited to explain historical information about the rooms and paintings.

Interpretation manager Cressida Finch, has placed boxes of facsimilies, pictures, inventories and booklets in each room, highlighting interesting characters associated with the house, from Martha the maid, to Dido Belle, Lord Mansfield’s mixed race great-neice, Humphrey Repton who designed the grounds, and – as part of a children’s trail - Mac, a dog owned by Russian aristocrats who rented the house a century ago and buried their pet in the grounds.

“We’ve flagged up different personalities and social stories that will grab people’s attention – there’s the Mansfields who built it, Lord Iveagh who saved it in the 1920s and gave his art collection to the nation and a family friendly guide based on Mac the dog.”

There are also hands-on exhibits for younger visitors including a giant dolls house with figures to position, a backpack to fill with tools to explore the house, and family activities and craft sessions planned for the coming months.

The collection of world class artwork at Kenwood includes Old Masters such as Vermeer’s The Guitar Player, a Rembrandt self portrait and an early nautical painting by Turner. Other works include Romney’s painting of Lord Nelson’s mistress Lady Hamilton.

“The re-hanging has put the Iveagh paintings in a more sympathetic, comfortable and welcoming environment,” said Dr Jenkins.