[Shasown]

Isnt going to happen.

The land and all access to it is Elstree film studios, they do not allow public tours full stop! Probably due to insurance costs and extra security costs.

As for the house and its contents etc, thats all Endemols.

As for an extension of planning permission on the building there could be two reasons for that. They already knew that Channel were going to (or indeed already had) obtain the rights to air the program, or more likely, they wanted to sit down to discussions with Channel 5 and be able to state they had the necessary permission to continue with the location for the next couple of years (as a trial teriod for any long term contract).