The Botucatu House in São Paulo, Brazil, designed by FGMF Arquitetos, demonstrates how residential architecture can create fluid transitions between interior and exterior environments through a deliberate series of intermediate spaces. Completed in 2014 on a 1,086-square-meter site with a 522-square-meter building area, this residence explores the relationships between enclosed rooms and open areas. These transitional zones challenge conventional boundaries between balconies, leisure areas, and traditional spaces such as living rooms or home theaters. The approach draws on Brazilian modernist traditions while developing new strategies that can inform modern house design approaches prioritizing spatial continuity over rigid room definitions. The Botucatu House was designed by Fernando Forte, Lourenco Gimenes, and Rodrigo Marcondes Ferraz with a team of architects and interns coordinated by Marilia Caetano and Sonia Gouveia.
The Concept of Intermediate Spaces in Residential Design
Intermediate spaces function as buffer zones between fully enclosed interiors and fully exposed exteriors. In the Botucatu House, these spaces include covered balconies, poolside lounges, and semi-enclosed walkways that blur the line between indoors and outdoors. The architects arranged the enclosed spaces in distinct blocks under a spacious concrete roof covering, creating a fluid zone where residents spend much of their time in communion with the built and natural surroundings. The pervaded space that permeates all environments has either a simple ceiling height or a double-height volume depending on where the visitor stands and how the different internal volumes relate to one another.
Types of Intermediate Spaces
- Covered balconies that extend living areas outward under the main roof structure
- Semi-enclosed metallic walkways connecting distinct functional blocks across the site
- Poolside lounge areas with roof overhang protection for extended outdoor use
- Transition zones with double-height ceilings that modulate spatial perception
- Courtyard-like gaps between building blocks planted with vegetation
- Covered outdoor dining areas that bridge the kitchen and pool zones
How Building Footprint Influences Design Options
The 522-square-meter building area on a 1,086-square-meter site allows generous transitional zones that would not fit on more constrained parcels. The ratio of 48 percent building coverage leaves ample room for the intermediate spaces and landscape. Even on smaller lots, careful window selection for farmhouses shows how glazing placement can connect interior spaces with outdoor views, applying similar principles of spatial expansion and visual connectivity at a reduced scale.
| Space Type | Roof Cover | Enclosure Level | Primary Function | Approximate Area |
|---|---|---|---|---|
| Living room | Full concrete canopy | Glass wall, full | Main gathering area | 80 sq m |
| Covered balcony | Full concrete canopy | Open sides | Outdoor lounge | 45 sq m |
| Pool terrace | None | Fully exposed | Recreation | 60 sq m |
| Metallic walkway | Partial metal roof | Open sides | Circulation | Variable |
| Courtyard gap | None | Building walls | Garden framing | 30 sq m |
Concrete Roof Structures as Unifying Elements in Modern Architecture
The dominant architectural feature of the Botucatu House is its large concrete roof that spans across all functional blocks. This canopy references the modern architecture of São Paulo, particularly the work of Vilanova Artigas, who pioneered the use of exposed concrete as both structure and finish in Brazilian residential design. The roof serves both structural and symbolic purposes, unifying the separate building blocks into a single cohesive composition while providing shelter for interior rooms and intermediate outdoor spaces beneath a single planar gesture.
Structural Engineering for Large Canopies
Structural engineer Edson Bispo Ferreira designed the concrete slab to accommodate varying ceiling heights across the 522-square-meter footprint. Some areas feature standard 2.8-meter ceilings while others rise to double-height volumes exceeding five meters, creating dramatic spatial variation within the same roof plane. The roof structure allows column-free spans for flexible interior layouts and provides deep overhangs that shade intermediate outdoor spaces below. Ground analysis conducted by ReforSonda ensured the foundation system could support the concentrated loads from the concrete canopy on the site’s specific soil conditions.
Concrete Finishes and Long-Term Maintenance
The apparent concrete finish requires sealing every five to seven years to protect against moisture intrusion and staining in Brazil’s humid subtropical climate. When properly maintained, exposed concrete structures have a lifespan exceeding fifty years with minimal degradation. The material provides significant thermal mass that helps regulate indoor temperatures, absorbing heat during the day and releasing it during cooler evening hours. This passive thermal regulation reduces mechanical cooling demand substantially, an important consideration in São Paulo state where summer temperatures regularly exceed 30 degrees Celsius.
| Concrete Benefit | Performance Impact | Maintenance Interval |
|---|---|---|
| Thermal mass | Indoor temps stabilized 3-5°C | No direct maintenance |
| Structural span | Column-free zones up to 12 meters | Annual visual inspection |
| Exposed finish | No cladding material needed | Reseal every 5-7 years |
| Fire resistance | 2-4 hour rating | No treatment needed |
| Acoustic separation | Reduces sound transfer between blocks | No maintenance |
Organizing Functional Blocks Under a Single Canopy
The Botucatu House arranges enclosed spaces as distinct blocks beneath the concrete roof. Each block receives different exterior coatings that signal its function to visitors. This material differentiation helps visitors immediately understand that different zones serve different purposes without needing interior partitions or signage. Many showcase homes employ similar strategies to maximize spatial impact through clear functional zoning without relying on interior walls, though the Botucatu House takes this concept further by separating the blocks physically rather than just visually.
Material Differentiation for Spatial Clarity
- Living areas use full-height glass walls for maximum visual transparency to the landscape
- The kitchen features concrete block walls and floating cabinets
- Private sleeping areas use more opaque wall treatments for seclusion
- Circulation paths use metallic materials to signal movement zones
- The artistic panel by Fabio Flaks provides a visual anchor at key transition points
Landscape Integration and Site Response
Landscape designer Caroline Bueno integrated native plant species around the pool and walkway areas to reinforce the connection between architecture and site. The turquoise pool anchors the outdoor leisure zone, visible from the living room through the double-height glass wall. The metallic walkways connect the house to compensating slopes that occasionally form walls revealing the garden, creating a dynamic walk-through experience where the landscape changes as visitors move between blocks. This approach treats the space between buildings as equally important as the enclosed rooms themselves.
Glass Walls and Indoor-Outdoor Visual Continuity
The double-height living room features a massive glass wall that floods the space with natural light while framing the pool and landscaped grounds. This glazing strategy eliminates the visual boundary between interior and exterior, making the garden feel like an extension of the living space. The approach reduces the perceived distinction between inside and outside, which is central to the intermediate space concept that defines the entire project. Principles from passive house design employ similar shading and orientation strategies, though the Botucatu House prioritizes spatial experience over strict energy performance targets.
Balancing Transparency with Climate Control
The concrete roof overhangs prevent excessive direct sunlight from entering the living spaces during peak hours while allowing diffused light to penetrate deep into the interior. This passive shading strategy reduces cooling loads without sacrificing the visual connection to the outdoors. Single-glazed panels would be inadequate for thermal comfort in this climate, so the design specifies modern glazing systems that balance solar heat gain coefficient with visible light transmittance. The electrical and plumbing systems designed by Projhel integrated the mechanical cooling needs with the passive strategies provided by the architecture.
| Glazing Factor | Maximum Benefit | Design Consideration |
|---|---|---|
| Natural light | Reduces artificial lighting 40-60% | Glare control needed on electronic screens |
| Solar heat gain | Passive winter heating | Overheating risk without adequate shading |
| Visual connection | Expands perceived interior dimensions | Privacy considerations near property lines |
| Structural integration | Creates dramatic apertures | Requires engineered support frame |
| Thermal performance | Modern double glazing achieves U-2.0 | Frame material affects overall performance |
Lighting Design for Transitional Spaces
FGMF worked with lighting consultant Marcos Castilha to design illumination that emphasizes the gradual transition between interior and exterior at different times of day. The strategy considers how each space functions from morning through evening, providing appropriate illumination levels for daytime tasks and evening social gatherings. Lighting was designed by FGMF with consultation from Marcos Castilha, ensuring the architectural intent was maintained in the electrical plan.
Daylight Integration Strategy
During daylight hours, the glass wall provides ample natural illumination throughout the main living areas. The concrete roof overhangs prevent direct beam sunlight from entering during peak intensity while allowing diffused northern light to reach the interior. Skylights in the roof structure bring light into deeper portions of the plan, reducing the need for artificial lighting during most daytime hours. The varying ceiling heights create different daylight conditions in different zones, with double-height spaces feeling brighter and more expansive.
Evening Illumination for Outdoor Living
At night, strategically positioned fixtures highlight the concrete roof texture and metallic walkway structure. Pool lighting creates a reflective surface that extends the visual depth of the outdoor space well beyond its physical boundaries. Interior lighting is positioned to be visible from outside, making the house glow as a lantern in the landscape and reinforcing the visual connection between interior and exterior after dark. This approach extends the usable hours of the intermediate outdoor spaces, allowing residents to occupy the covered balconies and pool lounge well into the evening.
Applying These Principles to Residential Projects
The design strategies demonstrated by the Botucatu House can inform residential projects at various scales and budgets. The core ideas of using intermediate spaces, a unifying roof element, differentiated material palettes, and strategic glazing transcend the specific site conditions and can be adapted to different climates, lot sizes, and program requirements.
Implementation Steps for Intermediate Space Design
- Assess site orientation, slope, and natural features before positioning functional blocks
- Design a unifying roof or canopy that covers both interior rooms and exterior program elements
- Use different exterior finishes on each block to signal distinct functions to visitors
- Position glazing to maximize views while controlling solar heat gain with deep overhangs
- Plan circulation paths that pass through intermediate outdoor spaces rather than enclosed corridors
- Coordinate landscape design with architectural sightlines for maximum visual impact
- Engage structural and MEP engineers early to integrate passive strategies with active systems
For projects where energy performance is a primary goal, passive house remodeling lessons offer complementary strategies for thermal comfort and envelope airtightness that pair well with the indoor-outdoor design principles seen in the Botucatu House. Ultra-low carbon housing lessons from projects like Vancouver’s Vienna House demonstrate how material selection and embodied carbon reduction can be integrated with architectural quality, making these combined approaches suitable for environmentally conscious residential projects that do not want to compromise on spatial experience.