A 900-year-old museum will be transformed into a purpose-built community museum in the coming months after a three-decade wait.
Work on Merton Priory is set to be completed in early summer 2018, and will be followed by an education centre, performance space and physic garden in the early 2020s.
Merton Priory Trust Vice-Chair John Hawks expressed delight as the long wait for renovations comes to an end.
He said: “We’re very excited by the scheme after nearly thirty years of doing so many events and open days on a shoestring.
“The Chapter House will at last be getting what it deserves as a priceless piece of local heritage – a place with the real wow factor!”
The Priory was the site of England’s first Parliament, the first English law statute and a teaching institution that counts Thomas Becket among its pupils, leading to consideration for World Heritage Site status.
Founded in 1114, the Priory was dissolved by Henry VIII in 1538 and was only rediscovered in the 1980s, during excavations by Museum of London archaeologists for the foundations of a Sainsbury’s and Marks & Spencer superstore.
The museum’s construction began in November and is set to pick up in the new year with the site’s boundary wall being demolished to create space for the museum’s glass-fronted entrance.
Merton Council cabinet member for community and culture Nick Draper hopes the move will boost Merton’s bid to become London Borough of Culture for 2019.
Mr Draper said: “Thousands of people go about their daily business not knowing they are just metres away from such a historic destination.
“Once the new exhibition space is developed, visitors from far and wide will come to visit the Chapter House.
“This transformational project to make the Chapter House more accessible to everyone is a perfect of example of the cultural gems Merton has to offer the capital.”