Two South African companies say they will put the finishing touches on a seven-story building expansion constructed with hemp blocks later this year.

Hemporium and Afrimat Hemp, both of Cape Town, partnered to raise an existing conventional five-story building, 84 Harrington Street, to 12 stories by adding levels constructed with blocks from Afrimat Hemp.

Hempcrete construction brings along a private good through the lower operations cost of healthy houses, and a public good through a lower carbon footprint.