The new owner will have to install electricity, plumbing, flooring and walls into the 584sq ft space.

They also remained keen to preserve the original character of the house, and did not install electricity, gas or mains water until well into the 20th century.

But we can make them put in one-way windows if they want permission to install electricity.

Excavations in the last century stumbled across them, and since then workers installing electricity to the city have also come across the network.

He therefore came up with the proposal to set up a new building, and also to install electricity, but unfortunately both proposals were refused by the authorities.