Hemp Retrofit
Residence
West Village, NYC
Co-design: Gabriel Vergara
Hemp Workshop and Installaion: Hempstone LLC
Plaster: Robert Johnson
Workshop Participants:
Adam Glickman, Inés Yupanqu
Additional Labor: Andy Alfaro
Video Documentation: Lisa Schiller
Photography: Aidan Grant
West Village, NYC
Co-design: Gabriel Vergara
Hemp Workshop and Installaion: Hempstone LLC
Plaster: Robert Johnson
Workshop Participants:
Adam Glickman, Inés Yupanqu
Additional Labor: Andy Alfaro
Video Documentation: Lisa Schiller
Photography: Aidan Grant
This project is the first to utliize hempcrete in a New York City brownstone. Hempcrete is a bio-composite material that stores more carbon than it emits during its production and implementation, making it carbon negative.
The project--improving the thermal performance of the top floor apartment in an historic brownstone--presented an opportunity to work with natural materials. The existing condition was a brick wall, long stripped of its original plaster finish, and a timber ceiling.
Incompatible materials in historic buildings can result in moisture problems and material degradation. Modern materials also have a high carbon impact. For these reasons, I looked to hemp for its vapor open and super insulating properties. Hempcrete is a biogenic composite material made from the chopped up woody part of the hemp plant and mixed with a lime-based binder. It can be cast into a timber frame on site, or pre-cast blocks can be used to form walls. Hempwool is a fire-rated batt insualtion.
In order to minimize turnarond time between tenants, pre-cast blocks were sourced, instead of a cast-in-place approach. The blocks were set with lime mortar and the wall was finished with two coats of lime plaster. A workshop ran concurrent with the installation so that other architects could gain hands-on experience with the materials. Massachusetts-based Hemptsone LLC led the workshop and installation.
For the ceiling insulation, exposed joists provided about 8” of depth. Half of this space was given over to 3.5” hempwool batt insulation. T&G pine provides the finish on the underside. The new wood was stained to match the existing timbers
To complete the upgrade, electircal service was added to the ceiling cavity in front of the hemp wall and three pendant globes were installed.
Photos by Aidan Grant