A client has insisted on making a crucial change to a contract for a central London office refurbishment, following a bitter dispute between teams members over – what else – bacon sandwiches.

Developer Derwent Valley claims the project team, which includes project manager Buro Four, quantity surveyor Davis Langdon and contractor ISG InteriorExterior, spends more time bickering over breakfast than the usual bust-ups over variations, architects’ instructions, programme, claims and counter claims.

Derwent Valley director Paul Williams, who is overseeing the £26m scheme in Hatton Garden, explained the unique legal addition.

He said: “We were forever arguing over the quality of the bacon sandwiches at site meetings, so I got our lawyers to draft a definition of a bacon sandwich.”

The three-page addendum to the contract covers every eventuality. “If it’s cold, it is not a bacon sandwich. If it’s fatty, it’s not a bacon sandwich,” explains Williams.

The addendum also includes a clause on adjudication and gives contractor ISG InteriorExterior the right to substitute sausage for bacon if the site meeting is held after 10.30am.

Williams joked: “The contract conditions are pretty robust.

We have had only one major dispute, which took place when chicken tikka masala sandwiches were served at 8.30 in the morning.”