Rainy Sloped-Site Homes: Can the Roof Define the Space First?

Some residential plots in Shenzhen have level differences, or the house itself sits on a slope. In the early stages of a scheme, owners often first discuss the facade, terrace orientation and style, leaving the roof until last. A Casa Ensenada in Puerto Varas, Chile (Puerto Varas) offers a different order: this 155-square-meter house, designed by Paralelo Transversal and completed in 2025, places the roof in the position of organizing space rather than treating it as a finishing touch of form.^[1]

This house sits on a site of about 1.2 acres near Llanquihue Lake, with a rectangular plan, a large roof volume, and a terrace cantilevered over the slope. Architect Sebastián Silva told Dezeen that in southern Chile, rain is not an exception but part of daily life, so they wanted the roof to be more than a protective element—to form "a place under the rain," extending daily life beyond the enclosed rooms while gathering the different parts of the project under one continuous gesture.^[1]

What is truly worth a homeowner's attention in this passage is not the shape of the roof, but what it takes on. According to the report, the roof simultaneously organizes the functional arrangement, circulation, the relationship with the landscape, and the structure of the house. In other words, where the eaves cover, where the terrace extends from, and where people can walk on rainy days were all considered together early in the scheme, rather than adding a roof after the plan was finalized.^[1]

The report also mentions the treatment of the roof section: thickened in the middle, kept very thin at the edges, so that it looks like a light, continuous thin slab while providing structural depth for long-span trusses to cope with Chile's seismic conditions and Patagonia's strong winds. Here it is necessary to distinguish fact from inference: this is the media relaying the architect's statement, and the report does not provide structural calculations, material specifications or performance test data. It can show that the designers considered the roof as a structural main line, but it cannot prove that a certain roof approach applies equally in Shenzhen, let alone replace local structural and code verification.^[1]

For Shenzhen owners, what is transferable is the order of judgment, not the specific form of this house. If your own plot has level differences, is rainy year-round, or you want the terrace to be part of daily use, you can first ask a few questions: what activities should the space under the eaves accommodate, is there continuous shelter from the entrance to the terrace on rainy days, who carries the structure of the cantilevered portion, and where does drainage go. Only when these questions are answered clearly does the roof form have a basis; conversely, if the form is fixed first and structure and drainage are made to accommodate it, the cost often falls in the later stages.

The entrance treatment of this house is also worth comparing. The report describes that the house is located on a slope with a stream; residents and visitors approach along the stream, then turn via a ramp toward the house, entering at the boundary between public and private areas. On the narrower side are an open kitchen, dining and living space, extending toward the cantilevered terrace. What can be read here is the arrangement of spatial relationships: the arrival path, the entry position, and the connection between the public area and the terrace are considered together. As for whether this arrangement is convenient in actual living, the report provides no occupancy feedback, so no conclusion can be drawn on the reader's behalf.^[1]

Treating the roof as the main thread also has its costs. Once the roof becomes an organizing element, early-stage discussion of the scheme becomes heavier: the terrace's use, the extent of shelter and structural feasibility need to be clarified earlier, and the cost of changes is also higher. If the owner simply wants a conventional pitched or flat roof and treats the roof as form, the discussion can be lighter, but semi-outdoor space usable on rainy days may then require other solutions. There is no single answer between the two choices; it depends on site conditions, the family's need for semi-outdoor space, and how much discussion one is willing to invest in the early stage.

深圳市熹合空间设计有限公司 focuses on pure residential design and design implementation coordination, and does not undertake construction; design coordination cannot replace statutory engineering supervision, structural appraisal or construction warranty. Only having done residential work does one understand living—in discussions of sloped sites and rainy conditions like these, the company prefers to first clarify the daily activities and spatial relationships that will occur under the eaves, then judge whether the roof form and structural conditions hold, rather than fixing a direction from a picture of a roof.

If readers are currently looking at residential schemes with level differences or heavy rain, they can first do three verifiable things: first, list the semi-outdoor activities they still hope to use on rainy days, such as from the parking space to the entrance, or from the living room to the terrace; second, mark on the drawings the shelter range and drainage direction corresponding to these activities; third, for the cantilever and roof structure, ask the relevant professionals to verify against the drawing conditions, rather than judging only from renderings. This Chilean house offers an idea of putting the roof first; whether it suits one's own home still requires comparison with site, code and structural conditions.

It should be noted that Casa Ensenada is a project by Paralelo Transversal in Chile, with no commission or implementation relationship with our company. Its area, site and climate conditions all differ from Shenzhen, and the structural statements in the report come from the architect's account without engineering data attached. Treating it as a sample for observing design order is more prudent than treating it as a directly applicable approach.