The survey of 2,000 home buyers, announced to coincide with the launch of the new iPhone app 'Kirstie & Phil's House Hunter', has revealed that almost half (49 per cent) blow their budget on average to the tune of over £10,000.
For one in ten home buyers (10 per cent) the situation is even more extreme, with finances stretched to cover an additional spend of up to £50,000, whilst for a frivolous few (2 per cent) it topped the scales at more than £100,000.
One in five buyers (20 per cent) admit to getting caught up in the excitement of the moment, letting their heart overrule their head, whilst one in ten (10 per cent) don't factor in the cosmetic work required to make their new house a home. A similar number (11 per cent) are caught out by the level of legal and estate agent fees they need to build into their buying budget.
Stamp duty is another major issue, with more than half of house hunters (58 per cent) saying they are clueless as to the level they are required to pay when shopping and budgeting for their new home.
The House Hunter iPhone App is packed with videos and audio tip guides from Kirstie and Phil and contains a definitive guide to finance, mortgages, dealing with agents and legal processes.
Kirstie Allsopp said: "Going over your intended budget isn't always a bad thing if it means getting your dream home for a price you can still afford.
However with house prices as low as they are at present it should be a buyers' market, and so it's worrying to hear how many people are spending too much either because they're not striking a deal or because they're not on top of their finances."
Phil Spencer added: "We know from helping hundreds of people through the buying process that the same problems and pitfalls arise time and time again and that's why we've created the app. It's the first to combine an extensive property search function with great tools to help buyers manage their individual search."
Kirstie & Phil's House Hunter app is available from the iTunes store now and integrates the Zoopla search engine to enable users to search for properties anywhere in the UK.
House Hunter is packed with Kirstie and Phil videos as well as house buying tips and guides from Kirstie and Phil providing a comprehensive guide to buying a home.
The app has been jointly developed and produced by The Talent and Brand Ventures team at BBC Worldwide and Raise The Roof Productions.