Mud is building material of the future
Mud, mud glorious mud, there’s nothing quite like it for cooling the blood,” sang Flanders and Swann. An apposite consideration of the needs of a hippopotamus — but not a realistic recommendation, you might think, when it comes to human habitation.
Yet a school of thought is emerging that compacted and dried-out soil could be a building material of the future.
The Scottish executive commissioned a report in 2000 on the possible reintroduction of mud as a fabrication component, and scientists at the Centre for Alternative Technology in Wales have been assessing its benefits for the past 30 years, with positive reactions. Many countries have a tradition of mud building: adobe structures are familiar in the Middle East, Spain and Latin America.
About 100,000 mud buildings exist in the UK, many of which have been upright for centuries. People who live in such buildings are certainly positive about the experience.
Janette Anderson, 61, and her husband Francis, 64, brought up their four children in their mud cottage in Luthermuir village in Kincardineshire. Local historians have placed the construction date at about 250 years ago.
“It’s a bit of a family heirloom,” says Janette Anderson. “It has always been a very comfortable home. I often wonder what these modern houses will look like in 250 years’ time.”
Her great grandfather bought the property in 1904 for £50. Parting with his cash, he couldn’t have imagined the connection his family would forge with the unusual house.
“My grandmother got married in it. My mother Charlotte was born in it in 1912 and I was born in this house in 1947,” says Anderson. “But there was some stigma attached to it. When my son went to school, people used to say he was the kid from the mud hut home, but we always just knew it as a clay house. There are lots of them in Luthermuir, but, because of the harling, if you looked at it, you would never know it was clay.”
One of the advantages Anderson points to is energy efficiency. Mud buildings have high thermal mass and can store heat and release it slowly to balance indoor climate. In Germany, builders are being taught to work with mud again. The UK’s housing stock uses up three-and-a-half times the energy of homes in Germany and Denmark. Clearly, there are advantages, even if we are slower to recognise them in Scotland.
“Earth or clay buildings were actually traditional for thousands of years in Scotland,” says Tom Morton of Fife-based Arc Architects, author of Earth Masonry: Design and Construction Guidelines. “They still survive in Devon and are known as cobs.”
Despite being associated today with Third World countries, there is renewed appreciation of earth as an ecological, energy-efficient building material. It is free, biodegradable, produces about 5% of the carbon of concrete and is proven to protect inhabitants from asthma and allergies because of its ability to regulate internal humidity.
Much of the stigma attached to mud buildings comes more from changes in building fashion rather than any assessment of its merits.
The event about which mud fans are most excited, however, is about to be unveiled in a quiet corner of Angus. When the local authority granted permission to the guardians of Logie Estate to build on the site of an abandoned schoolhouse, it could not have known that the wrecking ball was about to flatten one of the best examples of a late vernacular mud wall building still standing in Scotland. Fortunately, an eagle-eyed neighbour with a knowledge of building heritage realised the error before the demolition team was called in.Logie Schoolhouse was constructed almost entirely from mud. Around the red clay fields of Angus and Kincardineshire, the area fictionalised by author Lewis Grassic Gibbon as Kinraddie in Sunset Song, such buildings were once common, but the tradition died out in the 19th Century.
Thanks to a £400,000 renovation, Logie Schoolhouse, constructed 178 years ago, will go on the rental market this summer as a one-bedroom home.
At its prime, the classroom echoed with the chatter of 40 local schoolchildren, before being reincarnated in 1920 as a community church for the local hamlet, which nestles between Montrose and Laurencekirk.
The reason for the partial collapse of one outer wall was more to do with leaking gutters and 18 years of neglect than any fundamental construction deficiency. The building was finally abandoned in 1990.
The National Trust for Scotland’s Little Houses Improvement Scheme (LHIS) secured the schoolhouse for a nominal fee, although access was initially impossible because of the overgrowth of briar and foliage.
“We couldn’t get in, but we knew it was a charming building, even if it was in a sad and unkempt state,” says Sian Loftus, the LHIS manager. “It had incredible potential.”
“Basically, there was a clay subsoil — there was lots of this in Scotland — and to make the mud walls they would have mixed it with straw and built it into the wall using hands or forks; somewhat akin to pottery, but on a huge scale,” says Morton, whose practice worked on the restoration. “People did this because it was cheap and easy,” he says. “It was also a local material, so you didn’t need to transport it.”
To preserve as much of the original structure as possible, Arc Architects and Little and Davie Construction dried out the schoolhouse and created earth bricks for any rebuilding using soil from the local farm.
“It is an attractive rural location,” says Loftus. “There is a nice view. It will appeal to someone who likes quirkiness and a building with lots of character. We have been very sensitive in adapting it, because we didn’t want to lose the long classroom or split it in any way.”
The good news for prospective tenants is that, under the terms of the Historic Scotland and Communities Scotland grants, the house must have a first tenure of six years and be priced within affordable housing guidelines.
Notwithstanding its rare materials, it also enjoys many unusual original features. What would have served as the classroom is now a kitchen, dining and living space with a historic fireplace. The head teacher’s quarters is now a bedroom and bathroom area. A porch, added at a later date, provides an entrance hall and cloakroom.
In the rear garden stands the ruin of a 1736 manse. The crowning glory will be the original school bell, lost for 18 years.
But then perhaps the real glory will be that an ancient form of building becomes popular once again as a way of helping the environment. “The use of earth is moving from the eco niche into mainstream construction now,” says Morton. “It is definitely going to happen.”