Restoration and conversion:

30 Princes Street

Thurso · 2017

Our role: Main contractor (with O'Brien Construction)
Client: The Highland Council
Architect: The Highland Council
Value: £1m to £1.5m
Programme: 2015 to December 2017
Scope: Emergency propping, masonry rebuilding and stone dressings, chimneyhead rebuilding, lime render, roof trusses and second-hand Scotch slates, basement tanking and Caithness flagstones, lime plaster and cornice restoration, joinery repairs, stair balustrade, conversion to three flats

30 Princes Street is a Category B listed Georgian town house of the early 1800s on the corner of Sir John's Square and Princes Street, in the heart of Thurso's conservation area. After years of neglect, the loss of its chimneyhead and rear stair tower and a compulsory purchase by The Highland Council, the building was derelict and at risk of collapse. We were appointed as main contractor, alongside O'Brien Construction, to save the structure, repair its historic fabric and convert it into three one-bedroom flats.

30 Princes Street, Princes Street, Thurso — photograph 1

30 Princes Street, Princes Street, Thurso — photograph 2

30 Princes Street, Princes Street, Thurso — photograph 3

30 Princes Street, Princes Street, Thurso — photograph 4

30 Princes Street, Princes Street, Thurso — photograph 5

30 Princes Street, Princes Street, Thurso — photograph 6

The challenge

The building had to be made safe before it could be repaired. Window masonry had become dislodged, the gable chimneyhead was gone, and cement pointing and render coated the sandstone externally. Inside, the floor structure and roof timbers were decayed, the basement was damp under its Caithness flagstones, and layers of modern wall linings and paint hid decorative lime plaster cornices, panelled shutters, architraves and a cast-iron stair balustrade that were to be kept. All of this had to be recorded, protected and repaired while the interior was reconfigured as three separate flats.

Our solution

Emergency propping went in first, then the external masonry envelope was rebuilt where it had failed: dislodged window masonry was taken down and rebuilt, replacement stone was cut to reform the window and chimney dressings, the gable chimneyhead and the original shopfront openings were rebuilt, and the cement pointing and render were removed before a self-coloured lime render was applied to the elevations. In the basement the flagstones were lifted, ground levels reduced, a tanking system laid and connected to new drainage, and the Caithness flags relaid on a new screed. Floor joists were strengthened or replaced, decayed roof trusses were spliced or renewed over new wall plates on consolidated wallheads, and the roof was re-sarked and covered with hand-selected, redressed second-hand Scotch slates. Inside, modern linings were stripped to save the historic lime plaster and cornices. Shutters and architraves were removed, stored and reinstated after repair. Years of paint were taken off the plaster and timber, surviving cornice profiles were recorded, lost enrichment was modelled and cast in timber moulds, and new lengths were run on site to patch into the original. Masonry walls were finished in lime plaster and the new partitions in plasterboard, with each flat given its own services, fire alarms, heating and ventilation. The cast-iron stair balustrade was cleaned and repainted, the sash and case windows repaired, and the rooms decorated with breathable distemper on the historic plaster.