Every homeowner wants to know the value of their property, especially when it comes to selling a house. But finding out the correct asking price is often hindered by conflicts of interest and inflated expectations.

Most vendors start by inviting a number of local estate agents to visit their house and provide a 'free' valuation, without appreciating that the estimates provided can be highly biased.

Homeowners setting their own price naturally tend towards the highest possible value based on emotional ties to the house and a desire to maximise profit from the sale of the home.

'House-price' websites offer DIY research into the value of properties sold, but this is less useful than it at first appears. Information is limited and difficult to apply to similar homes owing to the lack of comparative detail provided about the properties listed.

Unfortunately, neither the homeowner nor the estate agent are best placed to determine the worth of a property objectively, due to personal or commercial interests.

The commission an agent earns on the sale of your house is directly linked to the property asking price and hence they have a natural bias towards higher valuations.

In addition, the practice of 'overvaluation' by agents, in order to sign up customers, by suggesting that the house can be marketed at a very high asking price, only later to suggest a drop to a competitive level once you are tied in to a lengthy contract, remains common.

In their 2005 report on the property market the consumer group Which? presented evidence that estate agents' valuations can often vary wildly, in some cases by more than £100,000.

Setting an asking price too high can keep a property on the market far longer than necessary and it can even create a ripple effect of false expectations throughout the local property market.

There are numerous websites offering public access to Land Registry and Scottish Registry records giving the actual price properties have sold for, in any postcode.

Knowing how much your neighbours paid for their house can help you establish a value you can sell your home for, which might suggest that these sites are useful when researching your valuation. The problem with all these services is that they do not give you an estimate of a home's current value, only what it sold for.

There are further limitations, namely that the Land Registry only covers a fraction of all property in the UK (around 7 million homes) covering home sales since 1995. In addition, the detail on properties is sparse making it difficult to compare your home with those listed.