Architects Johan Selbing and Alondra Paz Vargas took a literal approach to hands-on architecture with the construction of Casa Tumán. After conceiving the project at their Amsterdam studio, they spent five months on site in Chile, stripping eucalyptus branches, mixing mud and stacking straw bales. The project – which is featured in the latest issue of Mark – is split in half, with the floor area shared equally between the private indoor spaces and the communal terrace. We spoke to the architects at their office in Amsterdam, following their return from South America, to find out more about what they had gained from the experience.

How did the project come about?
ALONDRA PAZ VARGAS: My family owns the plot. It’s about 700 sq-m and they wanted to have somewhere to use as a family holiday house. It would have been empty most of the time, though, so we thought about making it into a surf house that could be used by the local people while we were not there. We started thinking about how surfer people live and about the typology of the colonial houses in Chile.
JOHAN SELBING: We conceived the design as having an outdoor living room – the terrace is actually the communal socialising space – and that is because of the surfers; that’s how they spend their time. They go surfing in the morning and at night they come back and they play guitar or they barbecue and basically spend a lot of time together outside. Then, you have the four cells – the bedrooms – a kitchen and a bathroom.

What inspired the use of local materiality?
JS: The climate is very specific, so in the mornings there is a lot of humid vapour from the ocean and it’s completely shrouded in clouds. During the day, it gets extremely hot and at night it’s quite cold. It was a good thing to keep in mind because we used materials that are more fitting to that kind of climate: straw bale walls for good insulation and clay plaster to even out the fluctuations in humidity.
APV: We liked the idea of using local materials and a local workforce but we were also kind of forced to do it like that because we didn’t have transport and there was no way to communicate. The area is very isolated because the last part of the road is a dirt road, so it’s a bit hidden and really disconnected. We tried to get all of the materials from within a radius of no more than a couple of kilometres.

What was it like learning on the job?
JS: It’s such a physical thing. We noticed when we ordered the straw bales [for the main structure] that you start to think about architecture in a completely different way; the weight of materials and how to get them on site.
APV: You really had to think about the logistics and be creative and think about every detail.
JS: You learn to work in a much more improvised and spontaneous way. You look around and try to find things and ask for tips from people and they might refer you to something else. It was nice because it was like walking around in a big 3D model at 1:1 scale. You could stand and look at things that you wanted to change.
APV: Plus, you actually had the possibility of changing them because people are much more flexible in that situation. We could improvise a lot and it felt like we had a lot of freedom.

Did much change from the original design?
JS: We obviously had a sketch which we thought was final when we left the Netherlands but we had to change a lot with it, both aesthetic decisions and with the architectural layout.
APV: We changed a lot of details but the main idea was the same: we always had 50 sq-m of interior space and 50 sq-m of an open living room.

How do you feel about the experience now that you’re home?
APV: It was much, much harder than we expected and we had a lot of problems because of the location. We thought we could finish it in the few months that we were there but when we left it was maybe 70 percent completed. It was super tough and I remember I got very sick at the end and I just wanted to come back home but when you’re here and you see the final photographs and it’s finished, you forget and you only remember the good parts. The big gain from the project was being able to really submerge ourselves and experiment with the materials because it’s a side of architecture you never really learn or experience. That was the goal from the beginning; just to go there and be fully involved for this period of time.