Karu Materials is bringing European hemp-lime block systems to the American Southeast — bio-based masonry that stores carbon, regulates humidity, and insulates in a single material.
Request specs & pricing →Atlanta, Georgia — now taking project enquiries for 2026–27 builds.
| Block | Thickness | Face | R-value |
|---|---|---|---|
| Infill 70 | 70 mm | 590 × 285 mm | 1.01 m²K/W |
| Infill 110 | 110 mm | 590 × 285 mm | 1.59 m²K/W |
| Wall 150 | 150 mm | 590 × 285 mm | 2.17 m²K/W |
| Wall 200 | 200 mm | 590 × 285 mm | 2.90 m²K/W |
| Wall 250 | 250 mm | 590 × 285 mm | 3.62 m²K/W |
| Envelope 285 | 285 mm | 590 × 320 mm | 4.13 m²K/W |
| Envelope 320 | 320 mm | 590 × 285 mm | 4.64 m²K/W |
A hemp-lime block is insulation, thermal mass, and wall infill at once. Laid around a timber or steel frame, it forms a monolithic, vapour-open envelope — no cavity, no membranes, no thermal bridging at the joints.
The blocks are non-load-bearing and cut with ordinary hand tools. Walls are finished in lime plaster inside and out, or ventilated cladding.
Hemp hurd bound with lime does what few materials can: the plant stores more carbon during growth than the production of the block emits, by the manufacturer’s cradle-to-gate assessment. The wall it builds is breathable — moisture moves through and out rather than condensing in a cavity.
Lime makes the block naturally alkaline: no food for mould, no appetite for insects, and it chars rather than burns. Buildings in hemp-lime hold stable temperature and humidity with less mechanical effort.
Hemp-lime construction is in the 2024 International Residential Code as Appendix BL, and the first US jurisdictions have begun adopting it. Where the appendix isn’t yet adopted — including Georgia — hempcrete homes are permitted through the code’s alternative materials provision with an engineer’s stamp.
Karu Materials was founded by an architect. We come to your project with datasheets, EN test reports, BIM objects, and submittal support — not just pallets.
Straight answers up front: the blocks are non-load-bearing infill around a structural frame, and European supply means a typical lead time of 8–12 weeks — so talk to us early in design, not at framing.
Our blocks come from a purpose-built Portuguese factory — inaugurated in 2025 — that processes the raw hemp and presses the blocks on a single site, with the manufacturer growing hemp on regenerating Alentejo farmland.
Performance is tested to European norms, and every delivery ships with the manufacturer’s full technical documentation: datasheets, EN test reports, application manuals, and BIM objects.
Specification advice, samples, and pallet pricing for architects, builders, and owner-builders.
rachel@karumaterials.com →