If you own a listed building, home improvements are not as simple as they might otherwise be, so it's essential to play by the rules says Julia Gray

1. The older a building is, the more chance there is that it's listed. As a general rule, listing applies to all buildings built before 1700 and to most built between 1700 and 1840. The vast majority of listed buildings are Grade II listed, but more important ones are Grade II* and the most important are Grade I. In Scotland, categories A, B and C are used instead of grades. The listing applies to the whole exterior and interior of the building, and sometimes attached structures and buildings as well.

2. Listed buildings are considered to be of special historical or architectural interest of national importance. Listing doesn't mean that the building can't be altered or extended - it often can, but the local council will have more control over what changes are made to it and may refuse permission for alterations if it doesn't think they're appropriate. Listed building consent is required to make alterations and while some home improvements, such as internal redecoration, can often be done without consent, many others, such as removing original features, knocking down walls and changing the windows and doors, can't. Many local councils identify locally listed buildings, which are considered to be historically important to the area but are not officially listed. You don't require listed building consent to alter locally listed properties, but if you make an application for planning permission, the local listing is likely to be taken into account by the council.

3. Listed building consent is obtained from your local council and is a similar process to applying for planning permission - sometimes you'll need planning as well. Historic England (see historicengland.org.uk/listing/ for information on listed buildings) or Historic Scotland (www.historic-scotland.gov.uk) may be consulted by the council about whether the alterations would be appropriate, especially with more important listed buildings.

4. Before making any changes to a listed building, consult your local council's conservation department, as work that seems minor may require consent. The department should be able to offer advice about what sort of work is considered appropriate for the building - and what isn't - and the consent process. Altering, demolishing or extending a listed building without consent is a criminal offence and can result in a prison sentence and large fine, as well as other costs.

5. If listed building consent is granted, you'll probably have to use traditional building materials and techniques to comply with it. These are often more expensive and specialised than standard ones - traditional lime plaster instead of conventional modern plaster, for example - as replacements are often on a like-for-like basis.

PRODUCT OF THE WEEK

Make your kitchen refurbishment extra special by fitting a boiling-water tap - and never have to wait for the kettle to boil again. The problem with many of these taps is that they're very expensive and don't dispense normal hot and cold water, so they can only be a secondary tap and often have a large tank or tanks to find room for. This is not the case with the Redring RediTap (from £578, www.redring.co.uk). The RediTap is much cheaper than many boiling-water taps and dispenses hot and cold water, as well as boiling water. Its tank holds 2 litres of boiling water, which is bigger than most kettles, but a lot smaller than tanks for many similar taps, making it perfect for smaller kitchens. This tap is available in shiny Chrome or Brushed Nickel to match your sink, comes with a two-year warranty and has an insulated spout with a locking handle to prevent you accidentally turning on the boiling water.

HOW-TO TIP

If you're painting dark wood or an exposed-brick wall, you often find that the colour keeps coming through the paint, however many coats you apply. The answer is to use a stain block paint first, but most stain blocks are so thick that they're hard to apply to uneven surfaces like wood and bricks. Zinsser B-I-N Shellac-Based Primer Sealer (from £23.99 for 1 litre, Screwfix) is much runnier than most stain blocks and so easy to work into uneven surfaces. It also dries much quicker than most stain blocks - it's recoatable in just 45 minutes - and has lots of other uses, including priming glossy surfaces (even glass), blocking odours and sealing resinous knots.