Nature at the heart of renovation

These words are still echoing in the IsoHemp factory and in the minds of many sustainable construction professionals who were present at the inauguration. These words, which express an urgency to which we are very sensitive, are those of Bruno Deraedt, engineer-architect and manager of BAST architects & engineers.

He is also president of VIBE, the Flemish Institute for Ecological Building, which aims to advance regenerative building and to transform negative impacts on society and nature into positive ones. Bruno is immersed in the construction of the future on a daily basis, one that places nature at the centre of renovation.

This call to paradigm shift in the construction sector is a call based on extensive experience. He is part of a team of 20 engineers and architects working for more sustainable construction and renovation. Together, they breathe new life into castles, churches, old cinemas, but also newer buildings... by integrating the most valuable things nature has to offer. And more than that, by applying the cradle-to-cradle concept, they reuse everything that can have a second life. "These monuments are unique and very strong. It is important to use them to prevent them from degrading," he says.

"I've been in the business for 25 years and I've done a lot of interior insulation." One of the last challenges Bruno Deraedt took on was to buy a listed villa to set up the BAST offices and the UR.Zone concept, a business centre open to companies wishing to have a sustainable, ecological and social impact. "I always test it myself, so I know what I'm offering my clients.".

Two types of interior insulation

Bruno explains that there are two types of interior insulation. Firstly, conventional interior insulation systems that are made vapour tight, either by a vapour barrier or by the insulation itself. "But we're all human, there's always the risk that there's a little flaw or hole that lets moisture in."

Secondly, the active capillary insulation system, which naturally absorbs moisture and then redistributes it to the warm side of the insulation such as hemp concrete. This second solution is without doubt the most reliable. This is one of the reasons why they turned to sprayed hemp concrete in the first place. Without questioning the performance of the material, they found it difficult to install.

Application of lime hemp 

"Hemp concrete requires a lot of work and drying time," he says. The hemp blocks were the ideal solution for them. "They are dry, they are very suitable for irregular walls and you can hang whatever you want on them, they are very solid."

The IsoHemp blocks, combined with a clay plaster, give their offices optimal acoustic and thermal comfort, which delights all workers. Some of them even admit that it is more pleasant to work in this atmosphere than at home. "Nature provides us with exceptional materials and it is important to show our gratitude by using these materials to build new things."