For sale: one expensive property (rather difficult to maintain); local authority permission needed for the slightest changes to be made; administrative hoops to be jumped through; conservation officers to be kept sweet. Any takers?

Plenty, actually. The chance to live in a piece of British history exerts a tight grip on homebuyers' fascination whenever one of the nation's listed homes (450,000 in England alone) – from crooked cottage to historic mansion or 1930s architectural gem – comes to the market.

Despite the age of some of the homes, the listings themselves were only introduced as recently as 1947 - in a bid to keep the wrecking ball away from the country's finer old buildings as the Government embarked on a post World War-II modern building frenzy.

Today, English Heritage advises the Government on whether a building warrants Grade I, Grade II* or Grade II status.

While very few ever get the chance to live in a Grade I - listed building (those deemed of 'exceptional' international interest such as Buckingham Palace) or Grade II*-listed (of national importance such as Erno Goldfinger's iconic Trellick Tower in west London) many people's homes are worthy of enough 'special interest' to be listed as a Grade-II property – and are conferred with the special status.

"A common conflict for new owners of listed houses is that they want to add their own touches to the property but need official 'consent' to do so"

The prestige and esteem of owning a characterful listed home – as well as the sheer joy and romance of living there – are, of course, what attract buyers in the first place. As an extra incentive, alterations in keeping with the property are even free of VAT.

But prospective buyers can find themselves caught up in a tangle of officialdom and costly changes if they don't apply a hard-headed approach: and can even end up as unwitting criminals.

It's all down to a very common conflict for new owners of listed houses: people instinctively want to make changes and add their own touches to a property – but need 'consent' to do so as they're effectively looking after a slice of national heritage.

"Permission to make changes is granted by your local council's conservation officer – he will decide if any alterations you wish to make are acceptable," says Peter Anslow, who runs the Listed Building Owners Club set up to help owners better manage their own listed homes. "If you're planning to purchase a listed building with the intention of adding an extension, or plan to undertake extensive alterations, it would be – to say the least – sensible to have a conversation in advance."

"It's not at all easy," adds Melanie Bien, director at Savills Private Finance broker. "If you don't look after your listed building properly, the local authority can intervene and make you carry out repairs it deems necessary for the preservation of the building – you have to get permission for any changes you make." Fail to comply and you can end up breaking the law and being fined.

Whether it's a major job like adding an extension or a minor task such as pulling plaster off the wall or even painting the front door, you run the risk of trouble if you don't first check with your local council conservation officials.

High-profile figures to fall foul of these rules include designer Laurence Llewellyn Bowen and former Conservative MP Teresa Gorman, the latter hitting headlines fifteen years ago after being fined for making changes – unauthorised – to her Grade II-listed farmhouse; after a hefty fine, her old windows had to be reinstated.

The problem is, it can be difficult to know what to expect.

For example, take the common case of how to best make a new extension work with an old listed property: some conservation officers might insist that the new stone or brickwork be a replica of that used on the main house so that it all blends in neatly.

But other officers might take a different tack and argue that, in fact, your extension should look discernibly different in order to clearly mark where the old house ends and the extension begins – allowing you plenty of leeway to use a material of choice.

Either way, it can bring its own expensive price tag, Ms Bien adds.

"The cost of materials for listed properties tends to be greater than with regular renovations because you may need to source specialist materials, such as reclaimed bricks or tiles, in keeping with the style of the original building."

It may feel like a chore but always consult a specialist surveyor or architect before drawing up plans for changes; and, when then consulting the conservation officer, don't spare any effort to work with them smoothly – their co-operation will be worth its weight in gold.

Another pitfall to watch out for is de facto responsibility for all restoration work already undertaken before you bought: in worst case scenarios, you could buy a home featuring repair work that wasn't given the go-ahead by local authorities, and end up footing the bill. Make sure you go over every piece of documentation with a fine-toothed comb.

"Sellers of listed homes must now also consider a Home Information Pack that throws up tricky issues on account of their housing's age and design"

Sellers of listed homes must now also consider a Home Information Pack that throws up tricky issues on account of their housing's age and design: the 'energy performance certificate' (EPC) that measures how much heat is lost from the building.

English Heritage warns that, when applied to traditional homes, a low 'energy efficiency' rating can have a negative effect on a home's perceived price - and could actually encourage the homeowner to make energy efficiency "improvements" that end up further damaging the property.

It all turns on modern houses being designed to keep moisture out with impervious materials (cement or plastic membranes, say); traditional buildings were built to absorb and release moisture through 'breathable' materials instead, such as lime plaster.

By fitting modern impervious materials (such as aluminium foil- backed plaster-board wall insulation) into traditional buildings, you can change airflows and moisture - resulting in damper walls causing damage to fabrics.

However, English Heritage says that, with consultation from a specialist, almost every traditional and historic home can now accommodate some energy improvements without harm.

Watch out also for insurance. You'll no doubt already have home insurance but listed houses often have unusually high 'rebuild' costs because repairs and restorations in the event of a fire or serious damage must be to a very high approved standard: so double check your cover.

Don't be disheartened by all these caveats, though: while it might seem like an uphill struggle, the joys of living in a listed building may not be for the faint-hearted but the intrinsic reward of being the keeper of a part of your country's heritage is usually reward enough.

By Sam Dunn