Plans to extend a prominent seafront hotel have been approved – despite claims from opponents it has already ‘changed beyond recognition’.

The Sidmouth Harbour Hotel, formerly the Westcliff, is set add a larger gym with a separate access. Retrospective permission was also granted to extend the decking for the outdoor swimming pool.

But neighbours in listed properties claimed they were not made aware of the proposals until it was too late.

Some 21 people formally objected to the application, with one Peak Hill resident telling the district council: “Bluntly put, this feels like a ‘smash and grab’ raid for commercial profit on one of the most historic rows of houses in Sidmouth without any heed to the historic significance.”

Rupert Kent, a regular visitor to Sidmouth, said in his objection: “The hotel development seems to have changed beyond recognition since I was last here, and not for the good. [This development] would be out of keeping with the surrounding area, and serve to reduce the setting of the period buildings positioned nearby. Enough aesthetic damage seems to have been done to the environs already without this further monstrosity.”

Another objector said: “It seems the continued extension to the Sidmouth Harbour Hotel means that Sidmouth will, by stealth, lose its historical and natural facade. People come here to enjoy such historical surroundings and not to see a modern, all glass and uPVC structure, built on a high, steep-sloping promontory with its overbearing modernity. It must be extremely intrusive to residents both opposite and below it.”

An East Devon District Council (EDDC) planning officer said the concerns raised had been considered, but do not relate directly to this application.

The officer said the economic benefits of the enlarged gym would weigh in the scheme’s favour, adding: “Development which helps the viability and functioning of a hotel within a prime seafront location is important and gains significant support in policy terms.”

The impact on the conservation area and adjacent properties also had to be considered, particularly overlooking Clifton Cottage. The planning officer said views of the house are ‘extremely limited’ due to the separation distance and it was not considered that harmful overlooking would occur.

The plans had been supported by Sidmouth Town Council. EDDC granted planning permission.