As a chartered building services engineer, CIBSE membership committee member and staff member of English Heritage, I felt I had to respond to last month's feature about The Devonshire (BSj 05/06) and the unnecessarily emotive language used.

A good example of this reads: "…and with the hawkish demands of English Heritage, which was determined to protect anything of historical value, irrespective of whether it could be seen."

English Heritage is the government agency targeted with protecting the historic structures of England, whether they are listed buildings or scheduled ancient monuments. We do not restrict this to the parts that can be seen, the protection covers the whole building.

There is very little point in having a listed building that is riddled with holes and has vast parts missing. The building has to be viewed as a whole entity. It has an individual history and story to tell to owners, custodians and visitors alike. We try to retain as much of this as possible for future generations to enjoy when carrying out development works such as those at The Devonshire.

The fact that services had to be redesigned is part of the challenge presented to all building professionals when working on historical buildings and valuable experience is gained because of it. All of the building services staff employed within English Heritage come from the private sector and all have worked with the difficulties presented to them whilst designing commercial projects based around listed buildings. It means thinking laterally and it sometimes using new and unusual technology to achieve the required end result. The article goes on to demonstrate this type of thinking in the solution found for the cable distribution for power outlets, used after English Heritage declined to allow further chases in the walls.

We are not here to make life difficult for building professionals, but we have a duty of care to this country's listed buildings. This is what we are trying to do when we do not grant permission for certain types of work to be carried out, but we actively encourage the continued use of our listed building stock and realise that this will require intrusive work. Part of our involvement is about keeping this intrusion to a minimum - remember, building services only last 25 years, buildings last a lot longer.

Geraldine O'Farrell, senior building services engineer, English Heritage