WaCa Design and Julia Kosciuk Build a Guest House from Its Own Hillside in Southern Brazil

There is a particular confidence in a building that refuses to import what it can dig up from beneath its own footprint. Rochas Floridas Guest House, completed in 2023 on Brazil's southern coast facing Calheiros Beach, is one of four structures in a beachside compound outside Florianópolis, and it may be the most materially committed of the group. Designed by WaCa Design (led by Walter Cain) and Julia Kosciuk, the 224 m² house extracts granite directly from the rocky site, sources slate blocks from a nearby quarry, and wraps everything in Brazilian hardwood. Even the doorknobs were designed without metal. The result is not rustic posturing but a disciplined geometry set into a steep, boulder-strewn slope.

What makes the project genuinely interesting, beyond its low-embodied-carbon ambitions, is the way it braids autobiography into structure. Salvaged materials from the owner's childhood home, including the front door, floor tiles, and plumbing fixtures, reappear throughout the building in transformed roles: closet doors become headboards, old flooring becomes a dining room table, and repurposed metal details become railings and rain chains. The building is not a nostalgic reconstruction. It is a new spatial proposition that carries the weight of lived experience in its material DNA.

Rooted in the Rock

The house reads differently depending on your vantage point. From the bay, it appears as a timber pavilion floating above dense vegetation, its vertical slatted screens giving it a lantern quality against the canopy. From the hillside above, it flattens into a long horizontal volume that follows the contour lines with disciplined restraint. The two-story central cube is the organizing principle: volumes are added and subtracted from it to create balconies, overhangs, and terraces that negotiate the slope.

The terracing is not decorative. Stone retaining walls built from on-site granite hold the earth back, creating a series of plateaus that the building occupies without erasing the landscape's original character. Boulders that predate the project by millennia sit comfortably alongside new construction, and the architecture treats them as permanent neighbors rather than obstacles.

Timber as System

The staircase wrapping around a preserved tree trunk is the house's most photographed moment, and for good reason. It demonstrates the design philosophy in a single gesture: the architecture yields to the existing landscape rather than demanding the landscape yield to it. The tree trunk passes through the structure like a column that was there first, and the vertical slat balustrades echo it with their own rhythm of parallel lines.

All windows are made entirely of wood, a deliberate choice for an oceanfront site where salt air corrodes metal hardware quickly. Recycled plastic rope appears in railings, an unconventional substitution that performs well in marine conditions while keeping the material palette honest about its sources. The vertical timber screening that wraps the upper balconies does triple duty: privacy, ventilation, and solar shading, all without mechanical intervention.

Pathways and Thresholds

Arriving at the guest house is not a simple act of walking up to a front door. Timber walkways thread through planted slopes thick with agave, palms, and tropical groundcover, turning the approach into a decompression sequence. By dusk, these elevated paths glow against the dark vegetation, bridging between the compound's buildings and framing sequential views of the bay below.

A concrete staircase winds through a hillside garden where mossy boulders and tropical plantings have been allowed to encroach rather than be pushed back. The landscape design here is one of curated wildness: the bones are precise, but the growth is loose. It is a strategy that will only improve with time as the vegetation thickens and the materials weather.

Living Spaces That Frame the Coast

The living room pairs a concrete fireplace with a timber ceiling that channels the eye toward a wide opening framing distant hills. It is a room that knows exactly where it wants you to look. The material contrast, cool concrete mass against warm wood grain, gives the space a gravity that prevents it from feeling like a generic beach house interior.

In the dining area, exposed timber ceiling beams run the full length above a built-in banquette, with framed botanical prints mounted along the back wall. The dining table, made from the flooring of the owner's childhood home, anchors the room with a story that no new material could tell. A narrow timber-clad corridor on the upper level acts as a compression point: board-formed walls pinch inward before releasing you through a glazed door to a panoramic view of the coastal bay. These moments of spatial compression and release are handled with the confidence of architects who understand sequence.

Private Quarters and Wet Rooms

The bedrooms are lined entirely in timber, with staggered horizontal windows that frame tropical foliage in cinematic strips rather than offering a single uninterrupted panorama. The effect is meditative: you are given the landscape in portions, not all at once. Headboards repurposed from closet doors carry a subtle patina that new wood cannot replicate, grounding these rooms in a material history that the guests may not know about but will sense.

Bathrooms continue the timber plank vocabulary on walls and ceilings. Dark vanities and salvaged plumbing fixtures contrast with the warmth of the wood. Tall glazed doors open bedrooms and bathrooms alike directly to garden views, collapsing the boundary between bathing and being outdoors. The detailing is restrained but specific, and nothing feels like an afterthought.

Courtyard and Covered Ground

An interior courtyard punctures the plan, pulling light and air deep into the house. Timber screen partitions with vertical slats and glazed doors wrap this void, turning what could have been a dead zone into the social hinge of the building. The courtyard also enables cross-ventilation, a critical passive strategy when large windows are already positioned to capture ocean breezes.

At ground level, a concrete overhang draped with vines shelters hexagonal paving stones and a massive boulder that the architects simply refused to remove. The vine-covered soffit will deepen in character each year, and the boulder becomes a kind of found furniture. Meanwhile, a dark stone countertop in the kitchen catches afternoon sun through timber-framed windows overlooking garden foliage, connecting the act of cooking to the landscape outside.

Plans and Drawings

The lower floor plan reveals bedroom suites and a bunk room nestled among topographic contour lines and granite boulders, confirming that the site's geology was treated as a design constraint rather than an inconvenience. The upper plan shows living spaces, kitchen, and balconies organized around the central cube, with a material legend distinguishing wood from slate construction. A roof plan documents the garage, bridge connection, and terrace on the sloped site. The section drawing is perhaps the most revealing: it shows the multi-level structure stepping down the hillside, with a palm tree and water feature integrated into the profile. An interior stair view, clad in horizontal wood planks with a small window punched above, completes the picture of a tightly resolved circulation system.

Why This Project Matters

Low-embodied-carbon construction is talked about incessantly and practiced rarely with this level of specificity. Rochas Floridas Guest House does not merely specify sustainable materials on a spreadsheet; it quarries stone from beneath its own foundations, salvages domestic artifacts from the client's past, and substitutes recycled plastic rope for metal in marine-grade railings. The commitment extends down to the doorknobs, designed without metal. When a building sources this much from its immediate context, it becomes genuinely difficult to imagine it anywhere else, which is perhaps the strongest definition of site-specific architecture.

WaCa Design and Julia Kosciuk have also avoided the trap of letting material piety flatten the spatial experience. The sequence of compression and release through timber corridors, the tree trunk colonnade, the courtyard hinge, and the framed bay views all demonstrate a rigorous command of form. The salvaged elements from the owner's childhood home elevate the project beyond sustainability metrics into something more rare: a building with a biography. In a coastal region saturated with second homes that treat the landscape as backdrop, this guest house treats it as a collaborator.

Rochas Floridas Guest House by WaCa Design and Julia Kosciuk. Governador Celso Ramos, Brazil. 224 m². Completed 2023. Photography by Pedro Kok.

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