I’m sitting in the dining room, stretched out on a comfortable leather armchair, the fireplace to my side and a luxurious rug under my feet. I glance up at the people on the sofas next to me and we exchange amiable nods before returning to the books in our laps. From time to time, I look up at the portrait hanging on the wall in front of me, just to remind myself that I really am in the presence of Rembrandt’s Portrait of the Artist (c 1665), before continuing with my reading.

Kenwood House in Hampstead has always been a remarkable building – it’s a neoclassical masterpiece by the renowned architect Robert Adams, and is home to the finest collection of Old Master paintings given to the British nation in the 20th Century – but now it is even more so, having reopened last week after undergoing a major Heritage Lottery Fund-supported refurbishment project, which began in 2012 and cost just under £6 million.

“We think of it more as a revival than a restoration or refurbishment,“ explains curator Laura Houlison, as she shows me around.

“Our intention has been to make it look and feel like a house, as it would have been in its day, rather than like a gallery or museum. We want people to come in and sit down, spend time here, be part of Kenwood.“

And that really is the feeling that the English Heritage team have created. There are no ticket desks or rope barriers – instead, you walk into the bright and welcoming entrance hall, with its open fire and warmly-coloured rug, and are free to wander through the doors leading off it to the various other sections of the house.

The paintings that hang on the walls in each room have discreet numbers attached to their frames instead of labels or information boards next to them, so visitors can refer to a book containing the relevant information rather than reading it on a wall, gallery-style.

In every room, space has been dedicated to visitor seating, and the rooms have been furnished much as they would have been in the time of the first and second Earls of Mansfield and, later, the first Earl of Iveagh, who bought the house in 1925 to provide a home for his unique collection of paintings, which include Vermeers and Gainsboroughs as well as Rembrandts, and furniture.

English Heritage’s Caring for Kenwood project has included restoring Robert Adams’ original decorative scheme in the entrance hall, the staircase and the library, using detailed paint analysis; refurbishing the breakfast room, Lord and Lady Mansfield’s dressing rooms and the housekeeper’s room; and repainting and restoring the exterior to its 18th Century appearance, and completely repairing the roof.

The people sitting next to me get up and wander over to gaze at Vermeer’s The Guitar Player (c 1672) and are soon replaced by another couple, who settle into the seats and pick up the information books the others left behind.

Me, I won’t be going anywhere soon and, checking again that Rembrandt is still in his place, tuck my feet under me and carry on with my reading.