The purpose of the Hillside project is to build a community that prioritizes lowering carbon emissions in their homes and lifestyles. Elements of this project include low carbon building materials such as hempcrete, net-zero operational carbon, urban agriculture, and water conservation. Hall and Moskow has endeavored to find the best methods to implement these low-carbon solutions, which has led us to build the largest multifamily hempcrete structure in the United States.

Hillside Center for Sustainable Living, once completed, will be a 58-unit rental community consisting of 5 entirely solar-powered residential buildings, a Common House and a barn, and will have maximized acreage of permaculture for the purpose of providing fresh food to the residents. Hall and Moskow has worked tirelessly for several years to reach their development goals. With each new phase in the construction of our community, we have raised the sustainability and decarbonization goals, with our latest building moving to a tilt-up hempcrete wall system.  Now, we aim to reach another important goal: To get our message out to the people who would most benefit from our experience. We hope to lessen the pain and reduce the learning curve for other brave souls wishing to develop leading-edge sustainable communities by sharing the lessons we learned.

The Hillside Center for Sustainable Living is located in Newburyport, Massachusetts. At the time of this writing, it consists of three finished residential buildings, two of which contain one- and two-bedroom units, and one of which contains ten deeply affordable housing units. Our latest building, nicknamed Southrise, is in progress, set to be finished in February 2025.

Besides putting into practice the basic tenets of sustainable building and living, Hall and Moskow aims to be a pioneer in the use of non-toxic, bio-based building materials derived from rapidly, annually and agriculturally renewable field crops like hemp. We now know hempcrete, plaster, and air sealing backwards and forwards, as we have experimented with multiple sustainable building methods and reset our goals higher with each building, making it a laboratory for incremental improvements. Experimentation comes with risk, and Hall and Moskow has endured many wins and losses along the way. Southrise, the building currently under construction, represents another leap forward by changing from an EPS/Concrete wall construction to a full hempcrete wall.

Hempcrete, a novel but increasingly popular insulation and walling material, was selected to replace concrete for the exterior wall construction on the Southrise building largely due to the ability to effectively remove carbon. This building joins only a select few commercial constructions to utilize hempcrete at this scale globally, and is the first of its kind in North America. Instead of traditional wall materials such as stud walls with insulation or concrete, fiber industrial (non-cannabinoid) hemp sequesters an impressive quantity of carbon during its growth cycle, representing true removal in a finished construction - and it is also fully biodegradable at the end of life stage. Through trial-and-error, Hall and Moskow learned important lessons about hempcrete construction including the best weather conditions for application, the perfect thickness of the plaster coating, best fibers for reinforcement and the type of binder to mix before application.

Hillside has a commitment for all buildings to be PHIUS certified, and one of our concerns, with hempcrete, is that we would need to offset the heat loss through the “breathable” walls by being especially diligent with our air-sealing methods. We applied the traditional hempcrete exterior finish of a lime plaster recipe, but found that it did not provide the air sealing capacity that we needed, so we had to pivot to alternatives given the stage of construction. Our efforts paid off when we exceeded Passive House standards on our blower door test by an enormous margin. As we know, Passive House standards require a result of 0.06 cfm50/ft2 or less, and Southrise clocked in at 0.01 cfm50/ft2 during the last test.

Some of the consistent attributes of our residential units is that each unit will be supplied with a Zehnder heat recovery unit as well as all electricity being supplied by on-site solar panels. All residents have access to permaculture food production and on-site electric vehicles for temporary use.