A Lytham restaurant has lost its appeal over a canopy and glass balustrades at the front of the premises.
The operators of Spago put up the structures to allow extra dining space outside the main building.
But Fylde Council considered that in that particular form, they had breached planning control because the design was more obtrusive than the version which had been granted permission.
The building on Dicconson Terrace, built in 1825, is Grade II listed and part of Lytham’s conservation area.
The authority slapped an enforcement notice on the business in April this year, requiring the owners to either remove the items or make alterations so they complied with planning consent.
This led to an appeal by Spago, which has been dismissed by planning inspector Daniel Hartley.
He said in his report: “The works and development have failed to preserve the listed building and the character and appearance of the conservation area.”
Mar Hartley noted that although Spago had been given planning permission for a canvas canopy and glass balustrades, the structures put up contrasted noticeably with the designs which had been allowed.
He added: “The appeal development has the appearance of a more dominant and imposing front extension.”
A spokesman for Fylde Council said the enforcement notice requires compliance by mid-May 2019, six months on from the appeal decision, adding: “The notice requires that they either remove the canopy completely or they revise it to the much more lightweight structure which was granted planning permission some years ago.”
Helen Vavoso, who co-owns Spago with husband Tony, said: “The required amendments are minor and we are happy to work with the council.”