The Beltline Urban Farm Shed for Aluma Farms and The Atlanta Beltline Inc.
The Shed is reminiscent of traditional sheds yet is set firmly in the present day with a simple form driven by the program. A south facing lean-to roof distinguishes the building and allows the north façade to open to naturally ventilate the building; it is also translucent to allow the shed to glow like a lantern when seen from the Beltline. 100% of the building’s services come from the site, getting its water from a well (treating all its waste by infiltration and a composting toilet), generating all of its own electricity with PV panels on the roof.
Design ChallengeThe Shed was designed as a demonstration project to promote urban farming and off-grid sustainable design. The project’s primary goal: be completely off grid for power and water. This requirement drove the section of the building, with a very steep south-facing roof to optimize gain on the solar panels when it’s needed most in winter, reducing the size of the battery system. The team found this allowed other integrated solutions to take hold – the steep roof for the PV array created interior volume that expressed and enhanced the use of stratification of air in conjunction with high operable windows and a large ceiling fan as a passive cooling strategy. The south façade is a large thermal mass wall, expressed as board-formed concrete, to passively warm the building. One of the project mandates was to create as much shade as possible for the farmers during summer. To accomplish this, and accommodate larger equipment, the doors open out to create canopies, increasing the effective size of the building. To ensure sustainability for the materials and to complement the off-grid operational goals, the project reduced the embodied carbon as much as possible. The team worked with a local non-profit dedicated to repurposing construction materials. The three wood façades are salvaged from a local landmark. All the sinks, doors and plumbing fixtures (composting toilet not included) were also salvaged, avoiding both the addition of these items to local landfills as well as the energy required to create new materials.
Physical ContextSiting on the urban farm adjacent to the Beltline, the project site is highly-visible and will only increase in visibility as the Westside Trail sections of the Beltline are completed. The project’s form was driven by the off-grid technical requirements for power generation, the program, and the desire for it to be a demonstration project showing that these structures can be attractive and regenerative. This deep commitment to sustainability was applied to the materials used in the construction of the project, with extensive use of reclaimed materials from other local buildings.
Since the building is only 400 sf, one of the project mandates was to create as much shade as possible for the farmers during warmer months. To accomplish this, as well as allow larger tools and tractors into the building, large doors in the east and west facades open out to create canopies, increasing the effective size of the building significantly by providing shaded spaces beneath them. When open, the doors also have other benefits; they create large overhangs that prevent direct sunlight from entering the building as well as create large, lower openings that work with the high, operable windows on the north side to draw air though the building. Together, these strategies create a complete passive cooling system for the building that seamlessly merges the technical, sustainability, comfort and programmatic requirements. Rounding out this integrated system is a high thermal mass wall on the south that helps use diurnal fluctuations to increase comfort.