Article for "Building" Magazine

Genetically Modified foods are currently the target of many public debates, but can these debates have any relevance for the construction industry?
Since mankind moved out of caves plants have provided for most of our building material.
Any plant, or animal for that matter, may be subject to genetic modification.

Today the construction industry still relies on timber frames, joists, shuttering, flooring, screens around construction sites, textiles and paper, stairs, cupboards, even the architect’s plans and the builder’s tea.
In particular buildings depend on a ready source of suitable timber. Traditionally builders used whatever material was locally available. Local woodland was managed to meet the local demand. Coppiced willows, hazel, and ash provided light frameworks and screens. Within the coppice wood standard trees were allowed to grow to maturity – forty 100 year old oaks would be needed to build a large barn or house [2].

These trees, although managed, naturally adapted to colonise Britain as the last ice age retreated. And these trees also came with symbiotic bacteria and fungi, animals, birds and pollinating insects that helped them to establish new colonies and flourish. But most English woodland disappeared under the plough to provide for a quicker profit from sheep and wheat.

When subsidies were given to plant trees in the UK many of the symbiotic organisms had been lost. Forestry plantations are inoculated with specific fungi, but they still need to be sprayed to control pests and disease. Much of our timber now is imported, we are dependent on the global economy to provide our requirements.

Because of the long timescales involved in growing trees very little plant breeding has been carried out on them. It is also difficult to control tree pollination in order to select characteristics from chosen parents, partly because of the size of the mature plant. Today’s oak would be instantly recognised by our Celtic ancestors, but wheat, and the way it is grown, has changed totally.
Genetic modification allows the bioengineer to design a tree from scratch to give the properties required, and avoid all these problems of breeding. What if the insect repellent characteristics of the Indian Neem tree were put into larch? The timber might not need any preservative treatment, but the carpenter might need protective clothing to work with it, and it might affect pets and fish tanks.
This example is similar to plant breeding in that larch and neem could be similar enough genetically to interbreed if they lived side-by-side. If the required properties were found in a totally different species, perhaps some form of anti-freeze in arctic fish, and put in a deciduous tree, like oak, to extend their growing season, this is known as transgenic modification.
Although the initial design of the new plant can be quick it would take two or three life-times to identify all the effects on its growing and building environments.
The complex relationship of symbiotic organisms, pests, disease and predators that support and are supported by a tree is as yet poorly understood.
And what if a small trial takes place? The pollen from many trees is very light and travels a long way, the modified gene can soon cross-breed with "native" plants.
In order to protect their investment Bioengineering companies patent specific genes, these are not "new" genes but simply ones that they have identified. This means that they own the basic plant or animal material; they control the production.

Current GM food crops are designed for large field systems that give a quick return on investment and make no allowance for any timber crop. This method of farming, requiring lots of irrigation, herbicides, fungicides, and pesticides, and degrades the land such that it becomes impossible to grow trees as a complete environment there again for a long time; it would be like the re-colonisation after the ice age. Athough individual timber crops, eg willow, may well thrive on the nitrate rich soil. An example of needing to establish a complete environment occurred in Thetford forest where the land had previously had lime applied for agriculture. This alkalinity favours the spores of Heterobasidion annosum (Fomes) over beneficial fungi such as Peniophora gigantea. Fomes can result in considerable loss of value of commercial conifers due to rot or stain in timber.

How long can we rely on the global economy to supply our timber requirements?

The Soil Association Woodmark certificate [3], is one way of helping sustain our supply of raw material in conjunction with organisations such as the World Land Trust [4]. Consumers are placing a value on builders that can demonstrate an environmental awareness through such schemes [1].

Other faster growing plants can be used to meet some of our timber requirements.
Trials are currently underway in Europe and East Anglia using hemp as a building material.
In France a company called Isochanvre has built more than 250 houses out of a concrete substitute made from hemp chips mixed with concrete and lime. The material weighs only a seventh as much as concrete, but is a far better insulator. A 1,300 square-foot home can be built for less than £10,000 [6].

The reaction of consumers to GM foods and the demand for organic produce shows how future demand for environmentally friendly and healthy building materials may grow. The building industry has nothing to gain in the short term from biotechnology, but it can retain consumers’ confidence, and avoid the problems of global monopoly suppliers, when it embraces recognised traditional and environmental standards.