Architecture Structure and Management (ASM) was held liable for the majority of the £2.2 million overspend during the revamp of Plymouth & South West Co-operative Society's (Plymco) flagship store at Derry Cross, central Plymouth.
It was ruled that ASM should have told the client that the project could have been split, to allow retailer Argos to move into to a 2,500m2 remodelled area within the original building before construction work on the rest of the overhaul was carried out.
In addition, the practice was held liable for not advising on the possible use of cheaper balustrades, carpeting, lighting and wall finishes. These recommendations could have saved Plymco almost £175,000 on a project which eventually ended up costing the Society almost £8.2 million.
According to the judgment, 'ASM had an express obligation to advise on any possible saving and - was in breach of that obligation.'
There was also condemnation of ASM's insistence on using a two-stage tender process when the designs had not been properly worked-up at either stage.
The judge agreed with Plymco's claims that the plan 'was insufficiently designed and programmed prior to the contract' and that none of the 'ill-designed nature of the works' could be attributed to any contributory negligence on the part of the client.
Dating back to a project which started in 1996, the case did not come up for trial until March 2005.