Don't Move Improve: Caught in a period drama?

British townscapes are rich in their variety of building styles and ages. Much of the charm of many of our towns is generated by the contrast of starkly different buildings juxtaposed together, many of which have themselves been altered and extended over time. While these happy mixtures generally happened ad hoc, these days we have rules in place to preserve things.

To protect the integrity of the historic and picturesque, we have the system of listed buildings administered by local-authority planning departments, backed up by English Heritage and Historic Scotland. But what if you are thinking of buying a listed building? And what if you want to make changes?

In my experience, people generally fall for one of two significant misconceptions. The first error is to think that if a building is listed, then any alterations are out of the question – this is quite simply not the case. At the other end of the scale, many people assume that only parts of a particular building are listed.

I have heard countless throwaway comments along the lines of "it's only the front façade that is listed" or "that part isn't listed because it isn't original". This is nonsense. If a building is listed, it is entirely listed – the good, the bad, the ugly, the later extension, lean-to and all.

It may be that a building is listed due to a particular element of the design, but the whole building is subject to the listing.

In a Georgian terrace, for example, where the consistency of the terraced façade is important to the street scene, it may be acceptable to the conservation officers to propose to alter other parts of the building.

However, it is very risky to make assumptions on this basis, particularly assumptions that will guide decisions over whether or not to spend hundreds of thousands of pounds.

Such features as chimney breasts and purlin props in a roof space (which often need to be removed to convert a loft) are often prized by the conservation officers but are common examples of where people simply don't imagine that they are breaking any rules. It is very important to be careful, not just because you could get seriously unstuck financially, but (unlike most planning issues that are common law) because unauthorised demolition or alteration of a listed building is subject to criminal law.

So, while great care must be taken to both understand and obey the rules, it is also important to see that all sorts of alterations to listed buildings are perfectly acceptable and in many cases encouraged. The planning guidance for listed buildings acknowledges that buildings need a meaningful and relevant use to keep them vibrant.

A few years ago, we proposed alterations to a beautiful and historic old house near Westbury in Wiltshire. The house had been empty for some time and was not selling because while it was very large, it had few bedrooms and bathrooms.

Our customers were a family with several young children and we proposed two new bedrooms and a bathroom in the roof space. The proposals did not alter the exterior, other than the addition of two conservation-grade roof windows, but to create the rooms, we needed to alter some of the roof trusses.

This created a conflict in the guidance because while we proposed alteration to some of the "primary structure" (not encouraged!), it facilitated a more relevant use for the building. The local planning committee decided that the vibrancy that a young family would bring to the village outweighed the importance of authentic internal roof structure, and the project went ahead to a happy conclusion.

So if you are thinking about the purchase of a listed building with a view to changing it, the lesson is that while great care must be taken to understand both the rules and the qualities of the building itself, you may well be able to make the changes you hope for.

Hugo Tugman runs the design service Architect Your Home – www.architectyourhome.com

Project: making alterations to a listed building

How much will it cost?

Alterations to a listed building may cost significantly more than alterations to a standard house because specialist craftsmen and/or materials may be required. Thatching and stoneworking skills are in demand and this can push up the price. In one example, a simple ramp to replace three steps cost £11,000 because of the necessary specifications of the matching stone. The good news is that alterations to a listed building that do have consent are zero-rated for VAT.

How much hassle is it?

Just getting consent can require a great deal of consultation and this means time and patience. A recent project to replace a 1970s extension with a new, slightly larger one took the best part of a year to get through the planning system. So if you are planning to make changes in a hurry, you may need to think again.

What's the first step?

First of all, it is important to work out what you really want to do with the property – it is important not to cloud this consideration with what may or may not be allowable. Then ask to see the file for the property at the local planning office. This should include plenty of information on the planning history, which will give you lots of clues as to the feasibility of what you hope to do.

h.tugman@independent.co.uk