A couple whose ‘grand design’ for the garden at their £5 million home became a money pit are now suing their former close friend

Recruitment boss Peter Burgess and wife Lynn blame architectural designer Basia Lejonvarn for the gardening debacle at their house in Highfields Grove.

They are demanding £265,000 for delays, cost-overruns and a litany of defects allegedly left behind by builders.

Judge Alexander Nissen QC said the Burgesses and Mrs Lejonvarn had once been good friends and that the case was “a cautionary tale”.

Mr Burgess, head of Retail Human Resources Plc, and his wife were formerly neighbours of Mrs Lejonvarn in Cromwell Avenue, Highgate.

The court heard that the Burgesses wanted to redesign their garden and install terraces, paths and lawns. After rejecting a £150,000 quote from a landscape gardener they turned to Mrs Lejonvarn, 51.

Within months, she and Mr Burgess, 58, were engaged in an acrimonious “email war”.

He accused her of not being qualified to do the job, described the project as “a disaster” and told her: “You have overstepped the boundaries between friends”.

Mrs Lejonvarn, 51, insisted the work had been done “to a very high standard”. She told the couple they had misunderstood her role and that she was “merely involved as a friend who happened to have a professional background”.

Judge Nissen said: “Whoever was to blame, the relationship came to an end at this time.”

The builders were sacked and the project was completed by the gardener whose quote had been rejected. The Burgesses said the work had cost £265,000 more than if Mrs Lejonvarn had never become involved.

Judge Nissen said although the parties had not signed a formal agreement or discussed her fee, Mrs Lejonvarn was “heavily involved”.

He ruled that the Burgesses had been “clients” and Mrs Lejonvarn had provided services “on a professional footing”.

The decision means the Burgesses can sue Mrs Lejonvarn for alleged breaches of duty of care.