These Hempcrete Micro Homes Are Climate-Positive and Gorgeous

Long-time readers of this site will know that we aren't the biggest fans of the big homes we often see in North American suburbs. Not only is there a lot of wasted space inside, but they take a lot of energy to build and maintain, and that's not including the upfront carbon emissions that are associated with the materials they are built with. We need a radical reduction in upfront carbon emissions—especially in the building industry—and we need it now, not later.

But convincing people that we need smaller homes can be an uphill battle, especially in societies where the idea of "big" is often culturally equated to "better." Nevertheless, that hasn't deterred multidisciplinary designers like Brooklyn-based Kaja Kühl, who designed two hempcrete micro-home prototypes for a farm in upstate New York.

Completed as a collaboration with Pennsylvania-based architecture studio Coexist and architect-of-record Roger Cardinal, the homes are intended as a pair of guesthouses that were inspired by the humble vernacular architecture of local farmworker houses and cabins of the area. As Kühl tells Dezeen:

"[Historic] farmworker houses and cabins in the region, as well as other parts of the United States ... often feature a rectangular shape and a simple pitched roof shape that continued to cover a long porch. They had one room or maybe a small sleeping nook in addition to the main room."

The two structures share a similar aesthetic but were intentionally made to look distinct by modifying their roof profiles. One guesthouse features a traditional gable roof, while the other sports a roof that has a more dynamic slope to it. Both are clad with cedar wood shingles and black locust wood siding, and both are equipped with large outdoor decks that expand the interior space further outside.

But perhaps the most notable features of these micro-homes are invisible. For starters, they are built with hempcrete, which is an energy-efficient, water-efficient, and thermally-efficient building material made of hemp and lime, which is a low-carbon alternative to concrete.

The team consulted with Hempstone, and according to their calculations, the hemp in the two micro-homes sequesters the same amount of carbon as 330 tree seedlings grown over a period of 10 years. She says:

"The hempcrete did not disappoint, storing the greatest amount of carbon in both structures. Cellulose is also impressive without the additional health benefits that hempcrete provides. Ultimately, paying closer attention to embodied energy, be it through using more bio-based materials or materials processed with renewable energy is critical to reduce emissions in the critical short term, setting buildings on a path to reducing emissions in their design and construction."

The interiors are absolutely gorgeous too—exuding light and a deliberate simplicity that belies the beauty of the materials used.

The two dwellings are designed with passive house design principles in mind, so to maximize passive solar heating, the homes have their windows and sliding doors oriented toward the south and west.

Behind the walls, hemp spray insulation was also utilized.

The micro-homes are powered by electricity sourced from a solar photovoltaic array nearby and use water from a well located on-site.

Ultimately, Kühl's goal is to build climate-positive buildings that go beyond net-zero carbon emissions, with the further goal of removing additional carbon from the atmosphere. Kühl's estimation of the small house movement is nevertheless realistic:

"Well, how can a 400-square-foot dwelling make a big difference? It cannot. The objective... is to put the 400 square foot dwelling into a larger context. To use it as a vehicle to research, discuss and challenge the many scales of decision-making that lead to our enormous ecological footprint. From real estate markets to zoning regulations to global supply chains of materials to the very minute design and construction details that go into building an energy-efficient home. The 400-square-foot dwelling is part of a multi-scalar system of production and consumption. Attempts to be 'off the grid' do not change that. I hope that it can serve as some sort of prototype for small dwelling units, but even more so to spark conversation about our ecological footprint and how more information on how to 'act' on climate change will lead to a different climate activism."

It's a sobering thought, but rightfully puts the design discipline in a much larger picture where massive changes on all levels of society will need to happen; smart, sustainable design won't necessarily be the one thing that saves the world, but that doesn't mean we don't try.

To see more, visit Kaja Kühl's project diary, Building Climate Positive, and her website You Are The City.