HempLime Renovation: P.A. Hemp Home

New Castle, PA 2020 - 2022

PA Hemp Home is a pilot project in New Castle, Pennsylvania, executed to research, test, and apply HempLime insulation in the renovation of a small, affordable home.

We are proud to work on a HempLime home renovation, designed as healthy, affordable, and visitable housing. DON Enterprise in New Castle, PA, led the collaborative project called “PA Hemp Home”, supported by the Pennsylvania Department of Agriculture.

When the project began, there wasn’t an acceptable code for HempLime insulation. The PA Hemp Home was used as supporting documentation for the proposed Hemp-lime Construction appendix for the International Building Code, which will be implemented in 2024.

PA Hemp Home was used as supporting documentation for the proposed HempLime Construction Appendix for the International Residential Code, to be implemented in 2024.

This project was an honoree of the 2021 Fast Co. Innovation by Design Awards for the Materials Category. It was also voted as one of the Top 10 Design Innovations in the United States in the television series America By Design from ByDesignTV. We are thrilled to be honored alongside designers and businesses who are solving the problems of today and tomorrow, and to see the enthusiasm for the use of locally produced, healthy materials for housing those who need it most.

DON Enterprise is a consumer-controlled, nonprofit organization in Western Pennsylvania that empowers people with disabilities to live as independently as they choose. Partners on the project are two expert HempLime builders: Cameron McIntosh from Americhanvre in Pennsylvania, and Alex Sparrow from UK Hempcrete in England. The Pennsylvania Housing Research Center at Penn State University will conduct energy and performance testing which will be disseminated to Pennsylvania businesses and residents. Healthy Materials Lab at Parsons is designing the house renovation and will conduct indoor air quality monitoring and testing.


For the Project PA Hemp Home, DON Enterprise acquired an 800-square foot, two-story house in the Lower East Side of New Castle, Pennsylvania.

DON renovates homes and builds new homes in New Castle, an Act 47-designated city. They administer several home repair grant programs that improve the accessibility and quality of homes across the city and surrounding counties. DON is testing the use of hemplime to renovate a wooden home as part of its revitalization program.

Pennsylvania Housing Research Center (PHRC) will analyze the thermal, insulative properties, and performance of hemplime as well as the resulting impact on utility costs in this residential renovation. A comparison will be made between thermal, insulative properties of hemplime and residences using typical insulation and construction.

With Masters of Architecture graduate Meryl Smith, HML co-directors Alison Mears, and Jonsara Ruth developed architectural and construction plans to renovate the home using hemplime for the exterior and interior walls. The ground floor is visitable, meaning that a person can visit without any accessibility issues, and human health is considered and prioritized at every stage. When the renovation is complete it will be a prototype for the renovation of similar houses in New Castle and other small cities nationwide. It will also expand uses for locally farmed industrial hemp. It will act as a model for the future of healthy, affordable and accessible housing, and prove to other developers that the radical change this industry needs is possible.

After the pioneering renovation has been completed, DON Enterprise will sell the house at an affordable price to a member of the New Castle community.

Jonsara and Meryl visited the job site to document the process of HempLime being sprayed into the walls. HempLime is a sustainable, healthy material that can be used to retrofit or construct the walls of affordable housing. The hemp and lime mix also creates breathable, highly insulated walls, producing a house that is durable and offers increased comfort compared with currently available housing. HempLime, a plant and mineral based material, is naturally flame retardant and anti-microbial which eliminates the need for any added toxic chemicals. HempLime walls continuously absorb odors, toxics, and carbon dioxide from the air making the indoor air cleaner than the air in buildings made from typical petrochemical based building materials.

After the spray-applied installation of the HempLime walls was complete, a lime-rich HempLime mix which includes hemp hurd, locally sourced lime, and sand was used to finish the interior surface of the walls. The mix is left overnight to mature. The next day it is applied by hand, smoothed with a wooden float, and burnished with a wooden trowel. This mix and application method is a one-coat process. This surface will be painted with a white lime wash from, a local leading manufacturer and distributor of “green” mortars, stuccos, plasters and paints in Telford, PA. On the exterior, a rainscreen of rough sawn board and batten is installed. The Hemlock wood is locally sourced at a local saw mill. An air gap is left between the wood siding and the HempLime wall so that the wall can breathe.

Construction on this new climate resilient, affordable house is set to wrap up in April 2022. The exterior of the home was completed before winter, so construction could continue comfortably on the interior into the spring. After construction is complete, the house will be left vacant for 2-3 weeks to flush out the pollutants that were inadvertently introduced indoors during construction using a combination of natural and forced ventilation. After this period, Industrial Hygienists from Cardno ChemRisk in Pittsburgh, PA will conduct Indoor Air Quality testing and monitoring.


Left: Stair after HempLime installation. Right: Stair after Plaster Installation.

On Friday, April 22, 2022, a ribbon cutting ceremony was held in New Castle for the completion of PA Hemp Home. Appropriately unveiled on Earth Day, the house is Pennsylvania’s first total renovation of a residential structure using hemp-based building materials, utilizing breathable spray-applied Hemplime in its walls and HempWood on its floors. During the event, we heard from representatives from HML, the Pennsylvania Department of Agriculture, Pennsylvania Housing Research Center, Americhanvre, and DON Enterprises. Each team member talked about the potential of hemp-based building, including the economic potential for farmers and the hemp industry, and the impact on health from the elimination of toxins in the building industry. After the program of speakers, members from the community were invited to tour the home a few at a time.

watch this short video produced by the Pennsylvania Department of Agriculture

The interiors were supported by our partners at Aronson’s Floor Covering, Columbia Forest Products, Daltile, and Floyd Home. Thanks to their generous donations, we are achieving the material health goals for this project.

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