Malawi cannabis and hemp company Invegrow has constructed its second hempcrete building at its Nangula plant outside the capital Lilongwe.
Invegrow (farm workers pictured above) has shared an SOP and open source video showing consumers how it’s done. The final outcome reveals hemp to be a cheaper, time-saving and durable construction material that enables many who would otherwise ill-afford it to own a home.
Unveiled under the theme, “Building differently, building for Africa”, the project showcases a truly practical, local solution in African habitat construction and ownership.
The low building is the company’s second hemp office at Invegrow’s farm following the one it constructed in 2016. It was built from scratch using hurd, dried hemp stalks, to strengthen the lime used in the building’s construction. Material for the low-cost, locally styled building was self-farmed and sourced from farmer cooperative groups.
“Not every solution needs to be high-tech or high-cost. Most people can’t afford that. Africa needs building methods that are accessible, scalable and grounded in reality,” an Invegrow statement read.
“Here we’re proposing a building product that could take a certain amount of the cement we use in construction and lighten it. By being lighter, we don’t need the foundation,” says project manager Paul Clarke.
The construction technique involves raft concrete pinned by poles. A ring of silicon sealant is placed on the bottom of the vertical poles to prevent water from coming up their hollow structure. The poles form the framework around which the shutters are built to construct the walls.
“What we’re doing with hempcrete is to substitute concrete in the walls in particular,” explains Clarke, adding, “Lime is what we use, not cement. Hempcrete itself is not only lightweight, it is slightly flexible and therefore in high winds and other things where movement occurs you’ll find a reduction in cracking of about 30%, compared to concrete.
That makes a big difference to the construction aspect.”
Local workers involved in the project said they looked forward to replicating the model in their communities. They lauded the building as the future of construction, building technology and skills.
Construction had intentionally been started in October to see if the hempcrete walls would withstand rain season storms, according to operations manager Peter Kondowe. There had not been any “alterations or any distortions from the climatic shocks”, he added.
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