A park café is set to be expanded to cope with growing demand, despite fears that this will damage the green surroundings.

West House Café, in Pinner Memorial Park, received unanimous planning permission from Harrow Council, enabling it to extend its kitchen into the adjoining car park.

The chairman of the West House and Heath Robinson Museum Trust, Cynthia Wells, said the extension was necessary to serve the growing number of customers making use of the café.

She pointed out that it has enhanced the park as a whole – transforming it from a "spooky space" to one that is enticing – and that an improved kitchen "will benefit all visitors to the park, café and museum".

Despite her assurance that the development will "not impinge" on the park, nor obstruct its view, neighbours argued that it will have a negative effect.

In a statement, those opposed to the plans noted the potential for "damaged grass", which represents a "slip risk", while the growth of the café, they said, will result in an increased number of pigeons at the site.

"We want to protect Pinner Memorial Park from overdevelopment; this is no longer just a café," they explained.

Harrow Council's planning committee was firmly behind the proposals – it believes that the café, and the museum, have been positive additions to the park.

But Cllr Stephen Greek said it should be wary about future developments and must assess the condition of the park when going forward.

He said: "I do understand the concerns about the expansion of the café and I wonder whether it has reached its limit now.

"While I don't think [this extension] is going to have an impact on the park, we should be extremely sceptical about any further expansion."