The Hill House, Charles Rennie Mackintosh’s domestic masterpiece on the west coast of Scotland, was “dissolving like an aspirin in water." Part of the reason for that is the home, considered "scandalously modern" when it was built in 1902-4, was also highly experimental in form and materials, says Kirstin Gamble Bridier (MSHP’02).
Bridier joined The National Trust for Scotland Foundation USA six years ago, and now serves as the organization’s Executive Director. In this role she raises American funds and visibility for the conservation priorities of Scotland’s largest conservation charity. But she says the value of the Hill House transcends the national borders of Scotland; it represents an important case study for the conservation of early modern architecture more broadly.
The Hill House was commissioned by Walter Blackie, a publisher interested in breaking with the vernacular architecture of the region. Mackintosh and his wife, Margaret MacDonald, designed nearly everything in the house, from the building to its furniture and the intricate decorative finishes throughout. The home’s rich, ornate interior creates a stark contrast to the sober, plain exterior. This stripped-down yet imposing look was key to Mackintosh’s avant-garde idea for a modern dwelling.
Portland cement was new to the market and cost effective for the vision. It allowed Mackintosh to experiment with new techniques and aesthetics, without coping, flashing, or gutters. But, not all of these experiments held up to the test of time. It rains 190 days a year in the west of Scotland, and the rain often falls horizontally. The Portland cement soaked up the moisture from the moment it was mixed, allowing water to penetrate the brick underneath. Bridier says the team found piles of red brick dust in the basement.
Bridier’s efforts at NTSUSA have been instrumental in combatting this decay. Having secured funding from the Getty Conservation Institute, the first step was a conservation assessment that will be the subject of a forthcoming publication.
The team debated the highest priorities in the conservation campaign. What was more important to preserve: Mackintosh’s distinctive aesthetic, or the original Portland cement? They decided on the look.
The inspiration for the Box came from the desire to treat the building as a design artifact and “put it behind glass.” “Obviously,” said Bridier, “doing that would cause a lot more problems than it would help.”
The Box is an ingenious and pioneering solution: its aluminum roof acts as a giant umbrella to prevent further moisture being added to the mix, while the semi-open sides made of chainmail allow air to circulate and dry out the building in a slow, natural fashion (drying out too quickly would make the walls crumble).
Each of the 30 million stainless steel loops in the chainmail surrounding the house was hand crafted—a true “labor of love” for the people of Scotland—and deliberately designed to allow pollinators to continue sustaining the gardens, but prevent birds from getting stuck in the new structure.
The Box has transformed the landscape of Scotland’s national treasure, which is still open to the public for tours and education. In fact its construction has opened up new ways to experience the space, with ramps allowing visitors to look down on the three-story structure as if it was a doll's house. It's lit up at night, and has become a tourist attraction in its own right.
However, Bridier wants to stress that the Box is only temporary. The goal is to completely dry out the cement for ten years’ time before the next stage in the conservation plan is to commence. That next step is still very much to be determined. The team at NTS are working with the Getty to determine the best material to replace the Portland cement harling—potentially something that doesn’t even exist yet.
If the 20th century represented an explosion of new building techniques, this century's challenge will be developing the vanguard preservation strategies to preserve those new materials. To learn more and support this work, visit the NTSUSA website.