In a rainy region of western Scotland, an architectural masterpiece has been given a new lease of life. Built in 1904, the Hill House is regarded as one of the most iconic residential homes to be designed by the famous architect Charles Rennie Mackintosh. After over a century, however, the masterpiece mansion is feeling its age.

The Hill House Box, designed by Carmody Groarke, was completed in 2019. Now, a new video by British YouTuber Tom Scott offers new insights into the original building, the issue with its façade, and the architectural intervention undertaken to save it, including interviews with the building's managers. 

Due to the wet, windy climate common to Scotland’s west coast, many buildings in the region are clad in a lime coating infused with small stones and pebbles. Once dried, the mixture forms a weatherproof layer to protect the building’s external walls from the elements. However, for the Hill House, Mackintosh departed from convention and replaced the lime coating with Portland cement, which offered a cheaper though less-understood alternative.

While the lime coating allowed water to evaporate off its surface, the Portland cement cladding of the Hill house has allowed moisture from the air and ground to soak into the building’s external walls for over a century. Reflecting on the ongoing crumbling and deterioration of the façade, the heritage group overseeing the home described the walls as “dissolving like an aspirin in a glass of water.”

For restoration efforts to be effective, the building must be effectively shielded from its surrounding environment to allow the saturated façade to dry out. This requirement has, in turn, led to an architectural intervention on the iconic house which is, in itself, somewhat iconic.

The large metal box, which has been shortlisted for the 2022 EU Mies Award, forms a protective enclosure around Mackintosh’s masterpiece to allow restoration to continue over the next 15 years. The box’s semi-transparent mesh façade is composed of over 32 million steel rings, making it the largest sheet of chainmail in the world, while a vast steel roof overhead prevents rain hitting the house.

More than a protective greenhouse around the historic house, the Hill House Box also serves as a temporary museum enclosure with a timber entrance building and a network of walkways for visitors to explore the building from above and around the structure. As well as the new birds-eye views, visitors will continue to be allowed access to the historic interior during the restoration process.

Following completion of the conversation work, the Hill House Box is set to be removed and repurposed elsewhere. As a result, Mackintosh’s unlucky masterpiece may finally stand firm against the grueling Scottish winters, one hundred years and three façade systems later.