In the world of sustainable construction, one question frequently arises: “How much does hempcrete construction cost per square meter?” At UK Hempcrete, this inquiry underscores a broader curiosity about the affordability and practicality of hempcrete as a building material

As the company’s founding director and hempcrete expert, Alex Sparrow explains, the answer is multifaceted and depends on various factors,including the type of building, its location, and the delivery model.

Alex Sparrow, Founding Director of UK Hempcrete

Assuming what is meant is the total development cost per m², it’s clear that this is a “how long is a piece of string” question. So much depends on other elements of the build, as well as the cost of the hempcrete and bio-based materials. Factors such as the type of building you are constructing, its location in the country, and the delivery model (self-build, subcontractor, turnkey main contractor model, etc.) all play a significant role in determining the final cost.

Most of our work, historically as contractors, has been in the domestic custom self-build sector, which has a slightly “premium” cost. However, we have always been at a comparable cost to any conventional construction method that meets a high standard of insulation and airtightness. Back in 2019/2020, when we were last building houses ourselves, this was around £1800-2200 per m² of habitable space. It’s also worth noting that through the last few years, since the pandemic, construction material costs generally have soared. Yet, being from local supply chains, hempcrete costs have remained fairly stable and have only recently crept up a little due to successive increases in fuel costs.

BUT, don’t forget, when I say “hempcrete construction build costs are about the same as other methods of construction,” it’s essential to remember that hempcrete (through its mixture of insulation and thermal mass) performs so well in terms of delivering a stable internal temperature and humidity that minimal mechanical and electrical (M&E) load is required to achieve a comfortable living space. Every house we’ve built to date just sits there, unheated, at 16-18°C all year round, whether it’s +30°C outside or -10°C. So this means the operational costs through the building lifetime make hempcrete a much cheaper way of building.

For self-builders who want to actively participate in their project, hempcrete is a really low-tech, accessible option. We can provide training so that they can install their own hempcrete, which has potential for significant cost savings as cast-on-site hempcrete is quite a labor-intensive process. If they have “free” labor from friends and family, hempcrete can seem like a cheaper option even at the build stage.

For developers, the additional features of a future-proofed, low carbon, healthy, and toxin-free dwelling can add considerable value and desirability to any development project.

We’ve moved away from contracting now, into the provision of specialist consultancy, architectural design, building modeling, and specification of structural and thermal envelopes using hempcrete and other bio-based materials. We also now provide product supply and are engaging in partnerships with architects and developers in the commercial sector to scale up hempcrete.

As part of our consultancy services, we offer cost-consultancy for hempcrete and bio-based fabric within any type of construction service. So we can review your project and help you develop a cost model, starting at an early stage and refining it up to the tender stage. We can also offer a specialist building modeling service which accounts for hempcrete’s unique performance in the building fabric and accurately predicts building performance. This is especially attractive to home owner-builders and commercial clients who will bear the costs of operational energy over the lifetime of the building.

When they see the twin cost savings (on capital expenditure at the build stage – on reduced M&E in the building AND the very low operational costs), they start to ask a different question: “Can I afford not to use hempcrete?”

For more information and to explore how hempcrete can be integrated into your next project, contact us via our website link: ukhempcrete.com/contact-us/