The HHA represents 1,500 privately owned historic houses, castles and gardens.  About 500 houses and 160 gardens open to the public, some with conference facilities.  Conference and accommodation facilities are also offered by another about 50 houses.  Together, these houses, castles and gardens attract some 15 million visitors each year.

Others offer unique venues for weddings, civil partnerships, dinners and other special events.

There are more privately owned houses open to the public than those in the care of the National Trust, English Heritage and their equivalents in Scotland, Wales and Northern Ireland put together.

These houses are an integral part of our national life:

• they attract visitors from abroad and generate income for the local and wider community, the great majority outside the entrance gate. 72% of Russians, a new market, say that historic castles and houses are a top reason for visiting Britain
• they constitute a rich and unique cultural heritage, as Britain's historic houses often still contain art and other treasures that have disappeared from their counterparts elsewhere in Europe - and most are still family homes
• they make inspiring places for learning outside the classroom: more than 150 HHA houses offer educational facilities
• people of all ages and backgrounds go to historic houses and gardens for recreation and renewal, and to enjoy our shared history. 

The costs of maintaining these houses, castles and gardens are significant - at least £80 million per year - and rising faster for many than income from visiting, because specialist conservation can be expensive, compliance with regulation is itself costly and competition is fierce, including from subsidised museums and galleries. Our historic houses are a fantastic asset for us all, but not one that can be taken for granted.