LongDrop
The Long Drop is a pioneering, no-cost composting toilet designed and built by Invisible Studio for its woodland workshop. Crafted entirely from scavenged and donated materials, it had zero financial cost and virtually no environmental impact
The structure was opportunistically designed around whatever materials were at hand: leftover studwork, battens, sheet materials of varying sizes, on-site cut timber poles, and steel bracing offcuts from the studio
Salvaged components include the ridge flashing from the nearby Moonshine project, polycarbonate panels for the doorway, and black fibercement tiles retrieved from skips
The toilet separates urine and solids directly beneath the seat. Urine is channeled via a drainpipe and can be used as fertilizer, rich in nitrogen, phosphorus, and potassium
Solids are collected in stacked donated wheelie bins and composted for about 12 months before becoming usable fertilizer
The “Long Drop” concept itself—allowing waste to drop directly into the composting chamber—ensures odor control, and an optional exhaust fan further enhances ventilation
The project embodies Invisible Studio’s research-driven ethos: rethinking design and construction methods through hands-on experimentation and minimal intervention
It serves as a pedagogical tool for demonstrating resource-conscious, waste-led construction—an architectural exemplar where low-cost, low-energy, and high-impact converge.
The design was shortlisted for the AJ Small Projects Award, and its viral spread in the press underscores its influence as a model of sustainable DIY architecture
The Long Drop transcends a simple functional structure—as a small-scale prototype it challenges norms around material sourcing, cost, and architectural legitimacy. Instead of expensive or high-tech solutions, it relies on available materials and local ingenuity, making a provocative case that authentic, ecological architecture isn't only for large budgets or glamorous contexts.