But renovators at one independent school in Yorkshire have done just that - revealing a 200-year-old room which staff never knew was there.

The discovery has been made at Bootham School, in York, which is refurbishing ten of its Georgian mansions.

The ballroom has been uncovered inside one of the townhouses when building workers removed a series of partition walls and false ceilings.

And because much of the room has been hidden it has benefited from a "benign neglect" with many of its original features still intact - including some impressive plasterwork and cornicing.

The school bought the house in Bootham in the late 1940s to use as accommodation for its teaching staff but as teachers moved into their own homes the flats became empty.

Bootham School had planned to bring the house back into use as accommodation for its pupils but it is now also developing plans for the room which nobody knew existed.

Headmaster Jonathan Taylor said: "This has been a really exciting discovery. The room is to be known as the Bootham Recital Room. It will make a wonderful space for music, for drama, for talks and for meetings and we are restoring it with both the school and the city in mind."

The school is planning to create a Bootham Recital Society which will allow people to attend a calendar of lectures and recitals. Renovation of the room is expected to be completed by Autumn this year, and the school believes it will be able to host meetings for up to 40 people.

Development director Jane Peake said: "We decided that we didn't really need a ballroom but this room will provide a perfect place for talks and recitals.

"Nobody knows when the room was last used but it has been hidden because of partition walls which we are now removing."

York Civic Trust has expressed delight at the prospect of the Georgian ballroom being brought back into use.

Trust member Darrell Butler described the find as "an undiscovered sleeping princess" adding: "This room is of a size and style that are all too rare in York."

The house is one of a series of properties which the school owns along Bootham which are being refurbished.

Mr Taylor said: "In order to keep everyone aware of what's going on, we have put up a number of information boards along the school frontage to explain what we are doing and, more interestingly, to give some historical background on the buildings themselves."

The school moved to 51 Bootham, in 1846, from its original site on Lawrence Street which it vacated because of the unhealthy surroundings of Foss Islands. The swampy land led to rats coming into the classrooms which meant teachers carried pistols during lessons and boys were posted as lookouts to warn of approaching vermin.

Over the succeeding decades, the school bought more buildings along Bootham, including number 49, which was the former home of Joseph Rowntree, the philanthropist and social reformer who had a foundation named in his honour.