The Mattos House in São Paulo, Brazil demonstrates how architects can turn a steep, challenging site into a design advantage. Designed by FGMF Arquitetos and completed in 2015, this 358 m² residential project occupies an 885 m² site on sloped terrain near one of the city’s main arterial roads. The project addresses the question of how to build on steep slopes while maximizing views and creating usable living space. Just as the modern barnhouse vision shows how site-specific design produces distinctive homes, this Brazilian project proves that topography constraints can drive creative architectural solutions.
Site Analysis Before Level Planning
Before designing the home, the architects at FGMF Arquitetos conducted a thorough analysis of the site conditions. The steep-sloped property faced one of São Paulo’s main arterial roads, offering a unique urban panorama. The slope direction, soil conditions, and view corridors all influenced the design approach. Window selection for the farmhouse in similar hillside contexts shows how important glazing orientation becomes when working with sloped terrain.
Reading the Terrain
The site sloped significantly from street level downward, creating a natural organization where the entry sits at the highest point. Rooms could cascade down the slope, each level benefiting from the urban view. The garage and main access occupy the first level, anchoring the house to the street while providing direct vehicle access. A garden sits at this level, creating a green buffer between the street and the private areas.
View Corridor Mapping
The architects mapped the view corridors from multiple points on the site. This analysis revealed that the best views opened up above the treeline at roughly mid-slope height. The living spaces were positioned to capture these sightlines, with the top-level living room enjoying an unobstructed panorama of the city. Mapping view corridors before finalizing room positions is a technique applicable to any hillside project, regardless of scale.
Level-Oriented Occupation Strategy
The team organized the house around a level-oriented occupation rather than a single slab or split-level approach. This strategy distributes the program across distinct horizontal planes that follow the natural terrain. The approach reduces excavation and foundation costs while creating varied spatial experiences across the different levels. Each floor plate sits at a height that corresponds to the slope’s natural contour line.
| Level | Functions | Key Design Features | Ceiling Height |
|---|---|---|---|
| Level 1 (Entry) | Garage, main access, garden, bedrooms | Street-level entry, private areas, garden outlook | Standard |
| Level 2 | Service areas, gourmet kitchen, dining room | Double-height dining, open plan, pendant lighting | Double-height in dining |
| Level 3 (Top) | Living room, solarium, swimming pool | Full view corridor, higher ceilings, external plateau | Higher than standard |
Reversed Program Stacking
Unlike conventional houses where public areas sit on the entry level and private spaces sit above, this design places bedrooms at the lowest level. This reversal responds to the slope’s specifics. Visitors enter at the bedroom level and move upward through the house toward the most public entertaining spaces. The approach maximizes privacy for the bedrooms while reserving the best views for the living areas at the top.
Circulation Flow Between Levels
A bare concrete wall connects all three levels and organizes the main stairway that links them. This wall acts as both structural element and circulation spine. The stairway becomes an architectural feature rather than a purely functional connection. Every transition between levels passes along this wall, creating a consistent spatial experience as residents and guests move through the house.
Mixed-Logic Structural Design
The house uses two distinct structural systems working together. A bare concrete wall runs vertically through all levels, providing lateral stability and anchoring the house to the slope. Lightweight steel framing supports the remainder of the structure, including the extensive glazed areas. This mixed-logic approach combines the mass and stability of concrete with the flexibility and lightness of steel. The concept of showcase homes inspiring real-world design applies directly here, where innovative structural combinations solve practical site challenges.
Concrete Wall as Structural Core
The concrete wall anchors the house to the slope while resisting lateral forces from the hillside. It provides the rigidity needed on a sloped site where differential settlement could otherwise become a concern. The wall also serves as a fire separation between the intimate and social zones of the house. On the leftmost side of the structure, this wall connects each level and emphasizes the vertical organization of the floor plan.
Lightweight Steel Framing Benefits
The lightweight steel framing reduces dead load on the foundations, which is particularly important on sloped sites where excavation is limited. Steel members can span greater distances than wood framing, allowing for larger glazed areas without intermediate supports. The steel system also speeds up construction because components are fabricated off-site and assembled on location. This approach minimizes the need for heavy equipment operating on the slope during construction.
Large Glazed Areas and View Optimization
The steel framing system enables extensive glazing on the upper levels. The top-level living room features higher ceilings and floor-to-ceiling glass that opens completely to the city view. Beyond the living room, an external plateau contains a solarium and swimming pool positioned to capture the panorama. Passive house design lessons demonstrate that large glazed areas on steep sites require careful attention to solar gain and thermal performance to maintain comfort year-round.
Double-Height Dining Space
The second-level dining room uses a double-height volume to create vertical drama within the otherwise horizontal organization. Pendant lights hang from the higher ceiling, defining the dining zone within the open-plan layout. The double-height space also improves natural ventilation, as warm air rises and escapes through upper windows, pulling cooler air through the lower levels.
- Higher ceilings on the top level improve natural ventilation and daylight penetration into the living spaces
- Floor-to-ceiling glass maximizes the urban panorama from the living room while connecting indoor and outdoor areas
- An external plateau transitions between the indoor living room and the outdoor leisure zone
- The solarium and swimming pool sit at the outermost edge of the view corridor, extending the usable space
Material Contrast and Visual Hierarchy
The design uses deliberate material contrast to create visual hierarchy on the facade. The intimate area appears as a heavy monolithic concrete volume above the social area, which reads as a light, glazed volume below. This juxtaposition makes the structural logic legible from the exterior. Passersby and visitors can read the building’s organization simply from the material treatment of each volume.
The material contrast also serves a practical function on the steep slope. The heavier concrete volume anchors the house visually and structurally against the hillside. The lighter steel and glass volumes reduce the perceived mass of the building, preventing it from overwhelming the landscape. This visual balance is an important consideration for any hillside project where the building’s mass must relate to the natural terrain.
Landscape and Pool Integration
The landscape designer collaborated with the architects to integrate the swimming pool and solarium into the slope. The pool sits at the top level’s external plateau, forming the transition between house and site. The steep slope provides a natural separation between levels while maintaining visual connection across the property. Passive house remodeling lessons show that landscape integration on sloped sites can improve the building’s thermal performance through strategic shading and wind breaks created by existing vegetation.
Construction Considerations for Hillside Sites
The mixed-structure approach at the Mattos House points to broader construction considerations for hillside sites. Foundation design must account for the slope angle, soil bearing capacity, and potential water runoff during heavy rain. Drainage systems need to redirect water away from the foundation rather than allowing it to pool against the uphill side of the structure. Ultra-low-carbon housing approaches increasingly specify steel framing for hillside projects because of its recyclability and reduced site disturbance during construction on challenging terrain.
- Steel framing components are prefabricated off-site, reducing the amount of work performed directly on the slope
- Lighter structural weight requires smaller, less expensive foundations that disturb less of the hillside
- Steel spans allow flexible room layouts that can adapt to irregular site contours
- Steel is fully recyclable at end of building life, supporting circular construction principles
- The combination of a concrete core and steel frame optimizes each material’s strengths for hillside conditions