Plans to convert a former military hospital into housing are being opposed by Dorchester town councillors.

The grade II listed building, which dates to 1799, sits in the middle of one of the county town's industrial estates. It has been used as offices, although has been vacant for a number of years – leading to vandalism, including an attempt to set a fire.

The site owner has been trying to convert the building for almost five years, with Barry Crook having an outline approval for five flats, as decided on the casting vote of a Dorset Council area planning chairman in November 2021.

It is now being proposed that the site would be better converted to three homes, with the conversion said to be the best way to preserve the historic building.

Councillors had previously been told that more than £400,000 had been spent in maintaining the site while waiting for planning issues to be decided, and it would cost a similar sum, or more, to make it viable again for commercial use.

Despite the wish to start work on the Grove Industrial Estate site, Dorchester town councillors have voted to oppose the latest application for one four-bed and two three-bed homes.

The proposal would leave the external appearance largely unaltered, which has been welcomed by Dorchester Civic Society as a way of preserving the character of the building.

Town councillors have previously claimed that an industrial estate was not a good place for anyone to live, especially families with children, but have conceded that their argument has been lost with the Dorset Council area planning committee vote by a majority of one, and that the principle of residential use on the site has now been established.

Town councillors will now oppose the latest application over whether the proposed development can meet the criteria for nutrient neutrality of water quality, as stated in the planning application.

Cllr Richard Biggs says the claim in the planning application is based on the site as a hospital, which it has not been for decades.

Cllr Les Fry told a town council planning committee meeting that there may be buyers willing to take on the site for commercial use, which was the preferred use. Local planning policy is that commercial sites should be retained, unless proven not to be viable.

Cllr Fry said he was concerned that if the site was converted to housing, other buildings on the estate, at least one in the same ownership, might also become homes in time.

He has asked for a decision to be made by Dorset councillors on the area planning committee, rather than be delegated to a planning officer for a final decision.

A planning agent for the owner said in a supporting document: "The building was previously marketed for office use, however there was a lack of local demand, and commercial use is not viable due to the requirement for a goods entrance – which would be detrimental to the heritage asset.

"The requirement for offices has now diminished further, due to the pull of office units on Poundbury, and the increase of working from home post-pandemic."

Cllr Janet Hewitt said she was astonished that Dorset Council members, not from Dorchester, had previously voted for conversion to flats, while all local councillors, who knew the site well, had opposed it.

The old hospital is one of a handful of buildings to remain intact from the days of the Maumbury Barracks. It was originally part of the Royal Horse Artillery Barracks and served the barracks and their families until the mid-20th century.

The site was also used by those held at the First World War Prisoner of War camp in Dorchester – which, at its peak held 4,500 men.

Many of the buildings which had formed the barracks were sold to Royal Mail and Dorset County Council in the early 1960s.

The application can be viewed on Dorset Council's planning website by searching reference number 23/03689, with public comments open until August 25.