A project to dry out Charles Rennie Mackintosh's Hill House in Helensburgh, Argyll and Bute, has reached a 'critical juncture' as workers begin removing the cement render that contributed to water damage. A giant steel box erected around the property in 2019 has protected the saturated walls from further weather damage, allowing them to dry out gradually.
The Hill House, built in 1904, has suffered from driving rain on Scotland's west coast. A Portland cement render applied under Mackintosh's instruction was thought to be a wonder product but failed to protect the building, leading to water penetration that damaged both the structure and interior decoration.
After several years sheltered by the steel box, the walls have dried sufficiently for the render to be painstakingly chipped off. Phil Long, chief executive of the National Trust for Scotland (NTS), said: 'It's difficult to overstate the international importance of Mackintosh and Macdonald and of the Hill House, and so delivering this project is of vital importance in preserving Scotland's and the world's design heritage.'
NTS said that in the coming months, specialists will finalise a replacement surface render that maintains Mackintosh's vision but allows the building to 'breathe', ensuring moisture is not trapped. The work is part of the Mackintosh Illuminated project, supported by £1.1 million from the National Lottery Heritage Fund.
Liz Davidson, NRS project director for Mackintosh Illuminated, said: 'By 2028, on the 160th anniversary of Mackintosh's birth, the Hill House should no longer need its protective box.' The project also includes internal conservation work and new interpretative materials.
