Licence fee payers could shell out £15million to pay for the new look EastEnders, documents have revealed.

Last month, the BBC announced it would expand and renovate the show’s 29-year-old exterior set at the BBC’s Elstree Studios in Borehamwood, increasing its capacity by 20 per cent.

In the meantime, the broadcaster would built a temporary set to enable filming to continue.

The BBC would not reveal how much this renovation would cost, saying it was “commercially sensitive”.

However a secret tender document seen by Broadcast magazine said the corporation was prepared to spend "in excess of £15m".

On the document, the BBC said it wanted to hear from people interested in providing "lead design and architectural services" for an "external film lot project within the M25 motorway" with a deadline of February 24.

It stated interested parties must be able to source "specialist products needed for visual replication of on-screen elements" and replicate "weathered and damaged building/structure facades and backdrops".

A BBC spokeswoman explained the document was only an “indication” of the scale of the problem and the actual cost might be very different from the £15m figure.

She said: “EastEnders is hugely important to licence-fee payers. This is purely a tender document to give an indication of the scale of the project."

The redeveloped site will be 9,000sq m, up from the existing 7,400sqm, and will feature new locations, streets and buildings, which the BBC says will guarantee the show's long-term future.

If Hertsmere Borough Council grants planning permission, work could begin later this year and be completed by 2018.

In the meantime, a temporary set will be built to enable filming to continue, and could later be used for tours and educational visits.

Borehamwood residents have welcomed the BBC’s decision to expand the EastEnders site and keep it in the town.

Leader of Hertsmere Council Morris Bright told the Borehamwood Times: “I am very pleased the BBC has decided to stay put.

“The BBC’s decision to expand the EastEnders set will bring jobs and money into the area and shows Elstree and Borehamwood will remain an important place for TV and film production for many years to come.

“It also quashes rumours that the studios were going to be closed down and used for housing, which will keep down concerns about overdevelopment in the area.”