Steel props installed more than three years ago as an emergency measure to stop the house collapsing are still in place. Now the Marsdens are suing Prudential Property Services, an arm of the Prudential Corporation, for pounds 75,000, arguing that their troubles started with a negligent structural survey of the house before they bought it.
'They employed somebody to do a structural survey who did not have the required expertise and we have advice from more than 20 experts that he was negligent,' said Mr Marsden, 33, a marketing consultant.
Mr Marsden and his wife, who have four young children, were living in London when they bought Hill House in Sapiston, near Bury St Edmunds. They decided that she would bring up the family while he commuted to work. Mr Marsden said: 'It was supposed to provide us with a better quality of life, but it has turned out to be a nightmare.'
Before they agreed to pay pounds 140,000 for the picturesque property, the Marsdens took advice from Prudential Property Services and paid pounds 750 for a full structural survey.
The 40-page report by the surveyor, Andrew Todd, concluded: 'My overall impression is that the property is basically satisfactory, although perhaps a little run down and becoming somewhat dated . . . Your proposed purchase price still represents good value for money.'
The surveyor, who now works for another firm, said that Hill House needed repair work and some additional bracing in the roof, but gave no warning about its fundamental soundness.
Three months after buying the house in December 1989 the Marsdens were given a more alarming verdict. Mr Marsden found that an oak corner post, one of the main structural timbers, was rotten, and called in another surveyor who was so worried he insisted a structural engineer should examine it immediately.
The new survey discovered that as well as the rotten corner post, two tie-beams holding the roof in place had been cut and a third removed altogether to allow extra bedrooms to be built. The sole plate, a beam around the bottom of the house, had been pushed off centre, and had started to crack under the stress.
In a subsequent report, Brian Morton, a structural engineer, wrote: 'It is my opinion that the problems of this structure should be obvious to an experienced surveyor. Mr Todd did not investigate in any way the condition of the members of the timber frame.'
He added: 'The whole structure bows outwards leaving the joists unsupported . . . Questions are thus raised about the overall long-term stability of the structure.'
Mr Marsden said: 'The house was in danger of collapse and we had to install engineers' props in the kitchen, the living-room, the bedrooms upstairs, and outside. They are still there 3 1/2 years later.'
The house needs repair work costing about pounds 60,000 but this was not covered by the building insurance because the faults were already there when the Marsdens bought it.
They decided to sue the Prudential for negligence and the case will be heard at Manchester Crown Court in March. The company denies liability but has placed the case in the hands of its professional indemnity insurers, Zurich Insurance, which called in a loss adjuster.
A Prudential spokesman said: 'Zurich have taken professional advice and they do not agree with Mr Marsden's statements. They will contest his views in court.' A statement by Zurich said it did not believe 'that there is a legal liability on the insurance policy arising from this claim based on the expert evidence we have obtained. We are unable to discuss the basis of this view in more detail as the claim is now subject to court proceedings'.