It is a big job, the £66m revamp of one of the finest art collections in the nation, the Burrell Collection in Glasgow.

But the plans are moving quite rapidly from drawing board to reality. Next year, if all proceeds as planned, the museum in Pollok Park will close, for three years of major building and outfitting works, and re-open in 2019. In the meantime, its treasures will both tour to international venues, and also be shown in a new exhibition at the Kelvingrove Art Gallery and Museum.

This week I saw the Masterplan for the whole project. The guide to the whole revamp is series of bound, intense, colour documents which lay out the case, the reasons for, and some of the gritty detail of, one of the most significant - and expensive - museum rebirths in the UK in the near future.

The Masterplan, put together by Glasgow Life, shows how radically the A-listed building will be changed by the project - which has been promised 50% funding from Glasgow City Council and is likely to receive a cheque from the Heritage Lottery Fund for £15m.

The redevelopment of the lauded but outdated 1983 building will include a much-needed new roof (the current roof leaks badly), new glazing and a major internal refit.

It will see the artworks collected by Sir William Burrell over seventy years, and gifted to the city in 1944, in almost their entirety for the first time. When the refurbishment is complete, more than 90% of the 9000-strong collection will be on display. The Masterplan shows a new 'third floor' or mezzanine. This will be used for "engagement and interaction" activities, for young people and school groups. The area will be used to show how Burrell's collected items were made, the skills used to make them, technique, craft, and context.

The ground floor will be re-jigged thoroughly. The current entrance, which the team behind the re-organisation (official designers/architects have yet to be appointed) believe leads to confusion, will be closed. Instead, the public will enter from what is now the side of the building, over a new, landscaped "civic events space". This new entrance will funnel the public into the centre of the building, where a new centre or orientation hub will be built.

Once inside, lifts and stairs will take the public down to a major part of the new building: the basement. This area, currently off limits, will become a public space, and a kind of open store, displayed (in the Masterplan, as very preliminary designs) as a kind of public treasure trove, with artefacts, antiques, paintings, sculptures, ceramics, furniture and other items closely on display. Here, more efforts will be made to explain how each item or collection of items (such as Chinese ceramics, for example) came to be in Burrell's collection. The re-introduction of context and history will be key to the new displays: why did Burrell purchase these things? How do they relate to the rest of the collection? The vast span, both of time and breadth, of the collection will be underlined.

The Burrell Collection museum is A-listed, so on the exterior, it will look much the same - apart from its new entrance. But inside, it will be almost like a new, £66m museum and gallery, which Glasgow believes will rival any civic collection in the UK, or further afield.