Mauricio Pezo and Sofia von Ellrichshausen founded their practice Pezo von Ellrichshausen in 2002 in Chile and have since gathered repute for their pared-back architectural proses, often benign, practical examinations of scale and proportions that remain lyrically bound to their remote contexts while conforming to no set vernacular. Dovetailed by their conceptual paintings, sketches, and models, their projects, often expressed in stark geometries of reinforced concrete, are case studies in quiet confidence and explorations of diverse typologies; part sculpture, part architecture.

In the same vein is their ROSA pavilion, standing serene and solitary atop a small hill rock in a bucolic Chilean setting, humble in dimensions and mien. Detached in its bareness, almost as a physical thing, the 40 sqm pavilion occupies the only geographical inflection on the course of a harsh mountain river, according to von Ellrichshausen and Pezo. ROSA is situated on the same rural site owned by the Chilean architects in Santa Lucia Alto, Yungay, Chile, where the duo has been residing and working for over a decade now, joining the LAMA pavilion, an observatory for contemplation and the firm’s residence and office, Casa LUNA.

“Together with LUNA and other pavilions, this small building is part of the necessary infrastructure for a large property, a natural reservoir, for the non-profit Fundacion Artificial. We are the founders and owners, but we prefer to believe we are mere custodians, provisionally taking care of the place for its persistence as a cultural and environmental institution in the future,” Sofia von Ellrichshausen tells STIR.

Bearing a square footprint, ROSA features a slender column piercing the middle of a geometric platform barely separated from the natural landscape it inhabits, vis-à-vis four thicker columns placed at the middle of each side. Crossed and diagonal beams embedded into the slab control the ‘rotational stress’ of the concrete structure. Underneath this opaque platform rests a ‘compressed room’ with the central column acting as the ‘structural chimney.’ Following the columns’ order, two corners have fixed glass panels and the other two feature sliding panels that can also be left as open balconies.

Inside, the pavilion architecture advances this bareness, empty but for the central hearth and a couple of furniture pieces strewn languidly across. “The interior can be understood as a hut lacking interiority, as a single room barely divided into four equivalent quadrants, with a minor variation given by a detached, monolithic staircase at one corner,” as Pezo von Ellrichshausen mentions. The minimal architecture can also be understood as a contemporary manifestation of a primitive hut with a fireplace warming its core, or as an observation platform. Apart from the scant furniture, the only colour inside comes from the dark brown-greenish pigment from the board ceiling. The rest is grey limbo. “All the rest is exposed in-situ concrete, without any tint or treatment. It is all handmade, even the pavement tiles were cast on-site,” von Ellrichshausen shares with STIR.

Below, massive glass panes enclose the concrete architecture, sheltering, exposing and vulnerable to its verdant site. Piercing through the terrace, the chimney takes on the role of a rudimentary sundial “for an imaginary record of circular time. Thus, the experience of this place is bound to its double nature,” they continue. We caught up with Pezo von Ellrichshausen for a more intimate reading of the pavilion’s design, the significance of its modest geometric assembly, and its aspects of separation and continuity framing life and nature.

Jincy Iype: ROSA emerges solitary and eagerly still from a geography spelt by a harsh mountain river in Chile—could you highlight the reasons for placing it in this context? Why is it named so?

Sofia von Ellrichshausen: 'Rosa’ is the Spanish name for a flower and a woman. But we are using it in reference to something else. ROSA, as the invented name for a place, refers to an ancient rural tradition associated with wheat cultivation, called ‘roce.’ The word means to burn the ground's surface, to prepare it for the next plantation season. We chose it because the pavilion is located at a former plantation site that for the last 50 or so years, has been covered by a pine plantation. By taking out the pine trees, to be replaced with native forest, we found the memory of such an open field.

Mauricio Pezo: The acute singularity of the hill, as much as its panoramic view, was hidden under a dark and dense shadow. The site is now back in its original condition, with a fireplace that somehow recalls its agricultural use.

Sofia: The very placement of the pavilion responds to pragmatic and symbolic dimensions. In practical terms, the object works as a lookout platform. Lookout means both contemplation and vigilance; visual attention for eventual wildfires, [in] an area that is meant to remain as a natural reservoir. Beyond that basic function, the location invites a deep immersion in the wilderness, for a sort of cosmic awareness.

In our view, buildings are legitimate fragments of nature, a second nature always validated by human drive… This is the fundamental ethos behind the buildings we do. - Mauricio Pezo and Sofia von Ellrichshausen, Founders, Pezo von Ellrichshausen

Jincy: How would you describe ROSA in a line?

Mauricio: It is a found object, an obsolete sundial.

Jincy: In its most rudimentary form, the structure is a simple sketched thought that comes to life: a platform band with a slender column at its centre, its roof accessible by a set of rail-less stairs, and a form barely separated from the terrain by its four, thicker columns. How did you arrive at this configuration?

Sofia: It is a deceivingly simple structure. But it is a rather complex system since it is a table-like object without legs on its corners. The form is a direct expression of such effort. The central column is the chimney, which allows a rotational pole. The diagonal beams connecting the four legs are hidden under the wooden ceiling. Thus, the feeling inside is the opposite of stress, it is effortless.

Mauricio: I don’t remember how we arrived [at] this form. We believe design problems and their internal processes are irrelevant [to] what things are, for how we read and understand their formal substance and effects. What is relevant for us is to promote a specific spatial experience. In this case, the open corners became a primary formal attribute. It allows for a continuous flow between interior and exterior, for an individual visual reference without ‘framing’ the panorama.

Sofia: This spatial continuity is further accentuated by having no window frames at the corners. There are two corners formed by glass-to-glass joints and two corners with sliding panels that can be [completely] opened so, eventually, there is not even glass on them.

Mauricio: The bold and scale-less staircase responds to another problem: Although it follows the diagonal alignment of the openings, on the sliding panels' corners, its sculptural presence has the purpose of separating the inner from the outer function of the pavilion. Whereas the inner function is somehow secluded, slightly sunken into the top of the hill, the outer one is that of an observation platform, elevated from the natural terrain.

Jincy: “Not only static but seismic, the rotational stress of this concrete structure is controlled by crossed and diagonal beams embedded into the slab.” Can you elaborate?

Sofia: This is what we were mentioning earlier. The seemingly simple structure is a literal diagram of forces, with vectors moving from the corners to the middle points and the plate, with a gravitational compensation given by a severe central symmetry. This can be easily read in one of our axonometric pencil drawings. The weight of the slab is distributed through beams, but those beams are not visible in the finished room.

Mauricio: On those drawings, it is easy to read the different thicknesses of beams. The central cross is thinner than the diagonals. Since the diagonal beams connect the columns, they are [making] the main effort and not the slab’s corners. The span of the cantilever feels larger because the real table is the one formed between the four legs and not the upper square slab.

Jincy: Besides their obvious minimal aesthetics and bare concrete geometries, how does ROSA relate to the other pavilions on site, LAMA and Casa LUNA?

Sofia: The three buildings belong to the same project, which is both a cultural and environmental one. Its central purpose is to preserve untouched native wilderness while promoting artistic interventions and events directly responding to it. Our basic intuition is to consider buildings as one more thing of nature, avoiding the traditional and rather romantic distinction between nature and architecture.

Mauricio: In that regard, despite its scale and program, architecture can be understood in reciprocity with natural forces, causes and processes. And yet, buildings belong to the domain of intentional things within nature. So, they become artificial after a mental activity, which involves intuition, perception and understanding. In our view, buildings are legitimate fragments of nature, a second nature always validated by human drive.

Sofia: This is the fundamental ethos behind the buildings we do. In the case of LUNA and the surrounding pavilions (apart from ROSA and LAMA, we are developing a few more), buildings are intentional, with a degree of separation and continuity. The three buildings are instances of the same principles. They can be read like magnifying lenses that allow us to see beyond, perhaps clearer and intensely, perhaps opaque and somehow deceiving.

Jincy: How is ROSA meant to be used?

Sofia: I like to read ROSA beyond its practical function. One could, for instance, interpret it as a sundial, with a vertical pole drawing the [passage] of time through its cast shadow. One could also interpret it as a primitive hut, with a fireplace at its core.

Mauricio: At an experiential level, one can enjoy the beautiful reflection of the landscape on the inner side of the windows. Since the enclosure of the room is made of large panels of glass, the interior is projected in all four directions. In a kind of dematerialised rectangular corners, one sees one hill reflected on a mountain and vice versa. Ultimately, the size of the small room is amplified by the size of the valley.

Project Details

Name: ROSA
Location: Santa Lucia Alto, Yungay, Chile
Surface Area: 40 sqm
Client: Fundacion Artificial
Architect: Pezo von Ellrichshausen (Mauricio Pezo & Sofia von Ellrichshausen)
Collaborators: Beatrice Pedrotti, Lukas Vadja, Theo Cozzi, Olga Arzur
Structure: Sergio Contreras
Construction: Constructora Natural
Material: Reinforced concrete