Bristol Hemp & Lime

Hemp Lime hygroscopic capacity

Bio-aggregate: hemp-lime, resolves moisture issues whilst also having the beneficial effect of improving the thermal efficiency of older buildings. The principles and materials used in traditional construction methodology prevent degradation whilst regulating temperature and humidity by capturing energy from moisture.

Improved loft insulation and double glazing make walls the coldest surface in the room, increasing the risk of condensation. External insulation is costly, complex, unsympathetic and retrofitting leave cold spots internally. Walls insulated internally with foam board lose the capacity to buffer temperature and humidity causing interstitial condensation. Bio-aggregate: hemp-lime is more than wall insulation reducing heat transfer through a wall, it also improves air tightness, has more accessible thermal inertia, and an increased surface temperature to improve thermal comfort. Retrofitting from cold and damp to warm and dry.

With over ten years of research, real-world collaboration and testing this system has proven itself to be both a thermally efficient whilst also resolving the moisture gradient issues associated with retrofitting insulation.


A successful installation is led by the process, the application must, therefore, be undertaken by trained practitioners. Workshops are now hosted by Neighbourhood Construction.

Teaching Part 2 Architecture students – materials unit – Centre for Alternative Technology

50 minutes

Case Studies

The following case studies document early prototyping of the process.

Victorian terrace
The damp Victorian terrace, built on a budget, what went wrong and what made it worse? How a century of bad practice was put right in a couple of weekends.

Hygroscopic bathroom
The steamy bathroom, need to be more than breathable, capacity counts, rapidly responding in layers, the wallpaper’s not for decoration.

Emancipated kitchen
The open plan kitchen, wreaking havoc in every home, enter the Bi-folding doors and the reveals expose a concentration of moisture.

Cold spots
Every home has Cold spots under repeated attacked from internal-weather, reduce the storms by tackling a more manageable project in isolation.

More recent examples are hosted by Neighbourhood Construction.

%d bloggers like this: