Measuring Embodied Carbon using the BEAM Estimator by Builders for Climate Action This article is part of the Building Climate-Positive, a project diary to build a carbon negative dwelling –exploring architecture and design solutions that address the climate crisis. One of the biggest motivations in using hemp and lime as a construction material was our interest in building “net zero” or “carbon-negative” or “climate-positive” or “carbon-neutral”– there are a lot of different terms being used, ultimately, it is about achieving a balance between the carbon emitted into the atmosphere, and the carbon removed from it.