About 15 years ago I watched an episode of Grand Designs where a woodsman called Ben Law built the most beautiful low impact cottage in the middle of the chestnut wood where he worked. At that time I had no idea what permaculture was, or that he was practising it, and even less that I’d one day visit him and have the chance to learn from his experience. Since finding out that visiting Ben would be part of my permaculture design course I’d been eagerly anticipating the trip. It didn’t disappoint.
We arrived on the day of the tour after a three hour drive, and sheltered from the persistent drizzle in an open sided building, the north side of which is formed from a fallen chestnut tree. Vertical growth from the trunk, cut to height, supports the roof joists. This is typical of Ben’s innovative building style, where he works with the materials to hand. Three large cast iron kettles sizzle on the open fireplace and the resident tom-cat takes a seat on the lap nearest the fire whilst Ben welcomes us and tells us his story.
Ben Law’s story
At 20 Ben heard about the deforestation happening in the Amazonian rainforest with an area the size of Belgium being cut down every week. Young and idealistic, he travelled to South America to try and help to stop the damage but quickly realised there was little he could do personally. While there, Ben spent time with the indigenous people and learned what he calls the ‘pattern of the forest’ – this is essentially permaculture ways of living, managing the forest sustainably and planting fruit along regularly walked paths.
On returning to the UK Ben worked in various forms of agriculture and woodland management. While working for a couple who owned a hundred acres of woodland, they expressed that the scale of land was more than they could deal with. Ben suggested his clients sell the land to someone who could handle it better. When the land had been parcelled up and sold, it turned out that the boundary lines had left eight acres unsold. Ben asked them if he could have it, with one catch, he didn’t have any money. Instead they agreed to barter for it, with Ben providing his services to the value of the eight acres.
Ben moved on to the land and spent a full year observing the woods throughout its seasons, and gaining understanding of the various species and biodiversity. This process of observing before acting is key to Ben’s approach, he’s passionate about creating habitat for endangered species and increasing biodiversity through careful management, seeing it as integral to the overall health of the woods.
After ten years living in temporary structures whilst negotiating with the planning department, Ben built the cottage at Prickly Nut Wood in 2002 as featured on the Grand Designs TV series. Ben still lives in the same off-grid house and hasn’t had a utility bill in 26 years. Although not fully self-sufficient, he has a sizeable vegetable patch, 70 apple trees, as well as pears, plums, chestnuts, beehives and collects other foods from the surrounding woods.
Since building his own home Ben’s become a leading expert in roundwood timber framing and has developed a number of unique techniques.
At the first stop on our tour Ben introduces us to the process of coppicing, an ancient technique for harvesting timber in a sustainable manner. The process involves cutting a tree down to ankle height, then in the following year new stems sprout from the edge of the stump and grow vigorously due to the large established roots. As the tree is coppiced in succession, new stems grow from the outside of the tree stump, with the number of stems increasing each time. Further growth can be encouraged by bending stems over to the ground and heaping earth over them, from which they will shoot new stems upward and put roots down.
Close planting of trees at around 2m spacing encourages straight vertical growth as the stems compete to reach the light, which also prevents side branches from forming – beneficial when producing timber, as side branches make knots which cause weakness in the wood. 12 years is the optimum period for growing the greatest quantity of biomass, after which the dominant stems begin to shade out the weaker ones which dieback, resulting in fewer larger stems per tree over time.
It’s important to balance the scale of coppicing each year to the overall size of the woodland to ensure it’s sustainably managed and that habitat is preserved. Each year Ben cuts 5 of the 100 acres he is responsible for on rotation. This area is surrounded by a further 1000 acres of woodland which buffers any impact. The area chopped down is allows enough space to be cleared to allow light to reach the floor creating new habitat, and maintaining the balance of older habitats at varying levels of maturity. To ensure the tree has plenty of strength for new growth cutting takes place between November and March when the sap stored in the roots.
All broadleaf trees coppice or sucker, and can be treated in similar ways, though some produce more useful timber than others. Surprisingly yew and monkey puzzle will also coppice even though they’re conifers.
The oldest known example of coppicing is in Westonbirt Arboretum where there’s a coppiced small-leaved lime tree which has been genetically dated at 2000 years old. This tree has grown so large over the years that at first the managers of Westonbirt thought it was a small-leaved lime wood.
Coppicing is one of the few processes where man’s intervention increases biodiversity. It does so by allowing light to reach the forest floor which stimulates wildflower growth and in doing so provides habitat for butterflies and insects.
Woodland biodiversity and habitat management
The vast majority of the land Ben manages is covered with sweet chestnut trees. The wood of chestnut is particularly durable and takes ages to rot, making it excellent for construction. Due to an increase of tree diseases moving across from the continent Ben is transitioning to a target of 80 percent chestnut. He achieves this transition by planting the other species amongst the chestnut and then coppicing the chestnut more frequently than the new trees, preventing them from being shaded out and allowing them to be become dominant in that space. If a disease were to sweep through and wipe out all of the chestnut, he would still be left with a viable woodland,. Ben goes on to explain that when managing woodland, you’re thinking of an entirely different timescale, planting trees which you’ll never harvest. This is part of being a steward of the land, maintaining it for the next generation.
Standing deadwood trees are left in place providing habitat for insects, birds and fungi. Ben and his apprentices also girdle some trees, cutting a ring of bark away so that the tree above dies creating another form of habitat – dying wood. That’s not the end of the trees life though, as it will begin to sprout from the base in the same fashion as coppice.
10–15 percent of the woodland is left as large, standard trees, towering above the coppice. Ben selects these for their good genetics and for gathering nuts, some of which will be planted. This balance allows for greater biodiversity due to varying habitat and for enough light to reach the coppiced trees below.
A large portion of Ben’s land is classified a Site of Special Scientific Interest (SSSI) as deemed by Natural England. This is due to certain rare species of moss found there – Ben actively works to encourage these species by coppicing trees slightly higher than usual, leaving greater area for the moss to grow up the stumps. Natural England conduct surveys of Prickly Nut Wood every 10 years and Ben uses the data to assess how his management is going – greater biodiversity shows his methods are working well.
Roundwood timber framing
When working with roundwood the timber is always used green, so there’s no need for lengthy seasoning and the wood is easy to work when carving joints and drilling.
When joining beams together a peg of seasoned oak is used to secure the connection. As the green wood dries it contracts onto the peg forming a tighter joint. It’s worth knowing that as round timber dries it always forms a radial split somewhere, this is normal and doesn’t weaken the wood.
Amazingly green roundwood has no movement or distortion as it dries, unlike squared off timber. Due to this Ben is able to create a-frame structures for clients months in advance of assembly and when they are put together on-site they fit perfectly.
Roundwood timber is an additional 50 percent stronger than if that same log were sawn down to square timber. This is mainly due to the wood fibres running the length of the timber not being cut through. Peeling the bark off increases the durability of the wood significantly as Ben found during tests on early buildings. Perhaps this allows the moisture to escape and the timber to dry out faster.
Ben showed us the difference between roof shingles and shakes – shingles are produced by cutting which opens up the wood fibres to the moisture like a sponge, whereas shakes are split using a tool called a froe, which leaves the grain intact and they therefore last longer.
We ask Ben if he worries about woodworm, or other pests attacking his house – he says it’s not a big concern to him, and just keeps an eye on the exposed beams. If you’re worried he recommends spraying new timber frames with borax salt when first built.
If you’re interested in learning more, Ben has a number of books and DVDs on coppicing, woodland management and roundwood timber framing available on his online store. He also runs short courses throughout the year. You can watch the full episode of Grand Designs featuring Ben Law’s house online.