hemp-lime construction

This new and unusual form of construction 'breaks the mould' of building methods. A mix of chopped hemp and building lime sets to a solid mass. The key use is to form solid external walls, but there is also scope to utilise it as a form of insulation to combine with other new constructions and in renovations.

Following experimentation by enthusiasts, Lime Technology Ltd. has seen the potential of this form of construction. They have formulated and branded their own 'Hemcrete' product, thus making available to everyone an accessible and predictable system with an associated body of technical knowledge and approvals.

We have utilised Hemcrete for the walls of an oak-framed new house and thus had the opportunity to appreciate fully what is involved in this type of construction and how to get the best out of it. It really does offer some exceptional qualities which set it apart from other methods and promises to provide highly energy-efficient, comfortable, natural and eco-friendly buildings.

The hemp is a very fast growing crop which produces a high volume of material quickly and efficiently. The lime component requires a traditional burning process for its production, but the energy use, (and thus carbon emissions generated), associated with that lime production process is said to be more than offset by the uptake

of CO2 from growing the hemp. In this way 'Hemcrete' is considered 'carbon negative'.

In addition to 'green credentials', the appeal of Hemp-Lime is in its simplicity and the exceptional environmental comfort qualities that have been achieved in those buildings constructed with it.

In particular hemp-lime buildings have shown a capacity to retain steady internal environmental conditions with a minimum of heating. In summer the buildings have also resisted overheating. The hemplime has shown itself to possess qualities that go beyond the familiar 'u' values which are quoted to prove the insulation factor of a material or construction

We therefore see a great future for Hemp-Lime and would be delighted to have further opportunities to utilise it. It has great merit for newbuild projects but has also been shown to offer great potential for the energy efficient renovation of old buildings, as it has an easy affinity with historic forms of construction.

View Sustain and build video on Youtube