The Friends of Bath Abbey has pledged £1.1 million towards a project aiming to make the abbey fit for the 21st century.
This week the abbey is launching a public fundraising campaign to raise £7 million towards its footprint project.
More than half a million people use the abbey every year and the project will increase capacity by creating a new underground visitor area, meeting rooms, toilets and a refectory.
It will repair the abbey's collapsing floor and will include a new eco-friendly heating system using Bath's unique hot springs.
The £1.1 million pledge from the Friends of Bath Abbey and the abbey's congregation has already given the fundraising campaign a massive boost.
Prebendary Edward Mason, Rector of Bath Abbey, said: "Less than six months ago the abbey invited its members to consider the footprint project by pledging gifts.
"In this short space of time, the total raised has risen to £1.1 million, an amazing response."
Earlier this year, the footprint project received earmarked funding from the Heritage Lottery Fund worth £10 million.
In order to unlock this funding, the abbey needs to raise around £7 million itself. The abbey community's pledge of £1.1 million means there will be less than £6 million to raise.
This is the first time the abbey has made a fundraising appeal directly to the public and it is hoped the £1.1 million pledge will encourage others to donate.
Jeff Jupp, chairman of the Friends of Bath Abbey, said: "As a member of this busy thriving church in the centre of Bath, I cannot fail to appreciate what a wonderful place the abbey is.
"While I hope personally to enjoy the changes the footprint project will bring to the abbey, what is much more significant is that it will bring lasting benefits for future generations. The changes we make now will be here in over 100 years' time and this is what I and the Friends are really pledging towards."
