Rain Harvest Home

This off-the-grid retreat  located in the mountains south of Valle Bravo, approximately two hours west of Mexico City, is strategically sited to provide views towards the 16,500-foot-high Volcan Toluca Mountain. Situated in a nature reserve, a key objective was to create a structure that could operate off the grid through a solar PV array and an on-site water treatment and storage system, working in tandem with the local climate where summers are wet and rainy, and winters extremely dry. 

The residence is conceived as a pavilion that allows for outdoor use year round. A raised concrete plinth clad with local recinto volcanic stone serves as a platform for interior and exterior spaces, while a hovering planted roof is supported by a perimeter colonnade of steel columns. Two-thirds of the pavilion is dedicated to covered outdoor space, allowing all sides of the home to breathe and remain open to the elements in the temperate climate. A detached bathhouse and studio complete the retreat’s ensemble of structures.

This collection of small structures in the mountains, two hours west of Mexico City, incorporates permaculture principles to establish a holistic, integrated relationship between people and place. Here, as in the surrounding region of Central Mexico, water has become an increasingly precious resource as temperatures rise and populations increase. Although the region sees a robust rainy season, rainwater harvesting is not common; instead, pumping in water from distant watersheds is standard practice. Rain Harvest Home takes a different track, proposing an integrated approach to designing regeneratively with water.

Environmental sensitivity:
Working in tandem with the local climate, where spring, summer and fall are wet and rainy, and winters extremely dry, the design team set out to restore the site’s microclimate, which had become eroded over time. The trio of buildings collect rainwater to integrate with an above-and-below ground reservoir system that collects, purifies, and stores rainwater to supply 100% of the home’s water year-round, enabling the home to operate completely off the grid.
- The on-site water treatment system is completely self-contained and primarily gravity-fed, containing five cisterns that provide potable and treated water.
- A chemical-free blackwater treatment system treats all wastewater on site, returning it to the site’s water cycle as greywater for use in toilets, and to irrigate the on-site orchard.
- Walking trails connect the various spaces and buildings on site, while also serving as bioswales that conduct rainwater to the home’s reservoirs and help prevent site erosion.
- A 10-kW photovoltaic array powers all thee of the buildings.
- Bio-agriculture gardens and an orchard on site are designed around syntropic agriculture principles to create a healthy, self-contained food system.

Design for integration:
Conceived as a collection of buildings in the landscape, the project includes a small residence, a detached art studio, and a bathhouse. Strategically sited to provide views towards the nearby Xinantécatl volcano, each structure gives over significant area to covered outdoor space for a seamless connection between interior and exterior. The main residence is conceived as a pavilion that allows for outdoor use year-round, with over two-thirds of the building footprint dedicated to covered exterior space. Nearby, the stand-alone bathhouse offers a poetic dialogue with the experiential qualities of water, supporting four bathing activities: hot bath, sauna, steam shower, and washroom. The rooms encircle a cold plunge pool at the center and open to the sky. All three of the structures share a tectonic vocabulary of recinto volcanic clad stone foundations and vegetated roofs.

Social impact
Rain harvest Home offers a model for designing regeneratively with water. Not only does the design help restore the microclimate of the site, bit it stands as a testament to the potential of rainwater harvesting for off-grid, self-contained water systems that eliminate reliance on municipal water sources. More than any other environmental element, conserving and improving the quality of water as a precious resource has the potential to dramatically improve the sustainability of built environments in Mexico, and beyond.