Plans to repair and replace parts of the roof at St Mary’s House in Portsmouth, a Grade II listed building, have been submitted to Portsmouth City Council.

The three-storey red and grey brick building on St Mary’s Road was first opened in 1846 as the Portsea Island Union Workhouse.

Designed by architects Augustus Livesay and Thomas Ellis Owen, it was built to house the city’s poor after the 1834 Poor Law Act. Over time, the site expanded to include an infirmary and a children’s home. By the end of the 19th century, it was at the centre of poor relief and health care for the area

Later known as St Mary’s Hospital, the building was converted into 68 self-contained flats in 1990 – today, all the flats are occupied.

Because of its age, parts of the building are now in poor condition. A roof inspection report found that water is leaking into the structure, putting the historic fabric at risk. The application explains that the works are “essential upgrading” needed to keep the building safe and to prevent further damage.

The proposals include part repair and part replacement of the roof, as well as the replacement of worn Velux windows and other maintenance. The work is needed because water is leaking through the existing roof and damaging the building inside.

Planning consultants for the project said: “The proposals support the continuation of the building’s active use, safeguarding and preserving the heritage asset for this, and future generations”.

Portsmouth City Council has already given early advice that the plans are acceptable in principle, so long as the work is carried out in a way that respects the historic character of the building.

The application concludes that the works will have “no change” to the historic significance of St Mary’s House but will help secure its future as both a heritage asset and a home for dozens of residents.

Residents can view and comment on the application on the council website using the planning reference 25/00954/FUL.