News Home & Design Off-Grid Ursa Tiny House Comes With a Distinctive Oval Window This exceptional custom-built tiny house collects rainwater and sun. By Kimberley Mok Kimberley Mok Twitter Writer McGill University Cornell University Kimberley Mok is a former architect who has been covering architecture and the arts for Treehugger since 2007. Learn about our editorial process Updated August 31, 2021 02:58PM EDT Fact checked by Haley Mast Fact checked by Haley Mast LinkedIn Harvard University Extension School Haley Mast is a freelance writer, fact-checker, and small organic farmer in the Columbia River Gorge. She enjoys gardening, reporting on environmental topics, and spending her time outside snowboarding or foraging. Topics of expertise and interest include agriculture, conservation, ecology, and climate science. Learn about our fact checking process Share Twitter Pinterest Email Joao Carranca News Environment Business & Policy Science Animals Home & Design Current Events Treehugger Voices News Archive You might have heard the motto "small is beautiful" before. Surprisingly, it is not a new phrase; this pithy bit of simple wisdom is actually derived from a seminal 1973 book titled "Small Is Beautiful: A Study of Economics As If People Mattered" by German-born British economist E. F. Schumacher. The book challenges the conventional idea that "bigger is better," expounding on the virtues of appropriately-sized technologies and people-focused economies. "Small is beautiful" is one phrase that you'll often hear echoed in the small space design movement, particularly when it comes to the push to make tiny houses more mainstream. In creating Ursa, an off-grid tiny house on wheels, Portuguese architecture and woodworking company Madeiguincho zeroed in on this phrase as its guiding star, ensuring that the result held true to the idea that simpler is not only better, but can help inhabitants live a life that is connected more intimately to the rhythms and forces of nature. Joao Carranca As reducing the overall weight of a tiny house is always a good idea, the 188-square-foot footprint of the Ursa is constructed primarily using a lightweight steel frame, with secondary structural supports made out of wood. The designers say: "For insulation, we adopted the concept of thermal envelope (passive design) and used 40-millimeter thick expanded cork boards." The tiny house is generously wrapped in a layer of wooden slats, which help not only to give it a distinctive appearance, but also to provide some privacy and shading against the hot Portuguese sun. The slats are made of thermowood (thermally modified wood), a sustainable wood alternative that is heated up to high temperatures in a controlled, oxygen-less environment, which alters the chemical structures of the wood's cell walls, thus increasing durability. Joao Carranca The slatted envelope can be closed... Joao Carranca ... or opened up. Joao Carranca To take advantage of the abundant sunlight, there are five south-facing rooftop solar panels, which power all the appliances and equipment of the home, including the water pump, water heater, refrigerator, and induction stovetop. The inclination of the panels can be adjusted in order to maximize solar energy production. Joao Carranca Additionally, in order to permit rainwater harvesting, the roof has a slight 5% slope so that water can run down the facade and into a gutter, which then funnels the water past a particle filter and cleans it before it's deposited in two large water tanks. The collected rainwater can then be pumped via a pressurized water system that directs cold or heated water to the kitchen and bathroom. Joao Carranca Past the large glazed entry doors, we come inside where the walls are clad with thick, high-quality birch plywood panels, and bordered with a darker colored wood. The layout is simple and includes two separate sleeping areas, enough for a total of four adults to rest in, a workspace, and a central kitchen and a bathroom off to one side. Joao Carranca The kitchen here feels warm and functional, thanks to the simplicity of materials and lines. There is a large rectangular window above the counter, as well as ample shelving, cabinets, and metal racks to hang containers and cookware. Joao Carranca Underneath the sink, there is a 3-stage reverse osmosis filter for purifying drinking water. Off to the side, we have tucked into a nook an integrated ladder that leads up to the loft bedroom. Joao Carranca The seamlessness of the spaces is emphasized by the decision to keep the continuity of the kitchen counter as it extends into the sleeping area to become the platform upon which the bed sits. Joao Carranca Overlooking it all is this stunning oval window, which is a unique take on the round window that we see more often in some tiny houses. Here, the oval opening seems to bend and drape over the roof, creating a window and skylight in one. Joao Carranca The designers say that some engineering creativity was needed to install this: "We had the privilege of being able to design and build all in a single place (carpintecture), but one of the biggest challenges of this project was the large oval window, for which we developed some fittings using a CNC cutting machine and taking inspiration from the connecting system of the wooden train tracks that we all used as children." Joao Carranca The lovely bathroom is done completely in wood—from walls, ceiling, and floor, to the hollowed-out wooden sink. To ensure that the house can function completely off the grid, a composting toilet has been installed. Joao Carranca As tiny houses become more popular, it's vital that we not lose sight of the original ethos of the movement: that "small and simple" is indeed beautiful, and to design accordingly. To see more, visit Madeiguincho and Instagram.