-By Mitzam Fontiveros

In a market that often prioritizes speed and industrialization, we sat down with architect Octavio Van Praag to understand the philosophy behind his most personal project to date: Casa Caña Dulce.

What began as a home in the heart of Guanacaste became a deeper reflection on family legacy, the climate crisis, and a return to living materials. In this exclusive conversation, Octavio opens the doors to his creative process and shares his “Manifesto,” a document that serves both as an ethical statement and as a bridge between the wisdom of his father, also an architect, and the urgencies of the future.

For Octavio, architecture is not a static structure. It is a living organism that breathes.

Below, in his own words, we share the essence of Casa Caña Dulce: an invitation to reconsider how we want to inhabit the planet.

For me, this project also represents something deeply personal.

Building this house in a new country involved years of effort, uncertainty, and a great deal of human labor behind every wall, every piece of bamboo, and every handcrafted finish.

And somehow, this house also ends up becoming an invisible bridge between generations.

Between inherited learning and new searches.

Between human fragility and the deep desire to continue creating spaces that care for life.

This house was born from a simple, but urgent question:

How do we rebuild without further depleting the world?

Today, the construction industry accounts for nearly 40% of global environmental and energy impact—a figure widely documented and easily verifiable in international studies on emissions and energy consumption. And yet, we rarely talk about it.

There is a silent contradiction in our time: we constantly talk about sustainability, but we continue to build almost everything with materials that have a very high energy impact.

Even in Costa Rica —a country internationally associated with nature and ecological awareness— construction continues to depend massively on cement and metal, often even within projects that are promoted as sustainable.

True transformation probably depends not only on adding “green” technology, but on profoundly rethinking materials, trades, and the very way we conceive of architecture.

Faced with that situation, we decided to take another path.

He wasn’t the fastest.

Nor the easiest.

It was an intense, artisanal, and profoundly human process.

A process of listening to the climate, materials, territory and natural rhythms of Guanacaste.

This house is not just looking to house people.

It seeks to demonstrate that another way of building is still possible.

Bamboo here does not appear as a superficial aesthetic gesture.

It is structure, shadow, texture, and ethical statement.

Due to its carbon sequestration capacity, rapid growth, structural properties, and low energy demand, bamboo is one of the most regenerative materials available for contemporary construction. Its extensive use in the structure and ceilings of this house was also a statement in response to the climate crisis.

But sustainability doesn’t depend solely on materials.

It also depends on how a house breathes.

The house was designed using bioclimatic principles that reduce the need for mechanical air conditioning. The internal courtyard maintains constant cross-ventilation, allowing hot air to rise and escape naturally while fresh air circulates continuously throughout the house.

Sometimes doors close unexpectedly on their own.

The house is not intended to behave like a hermetic machine.

It behaves like a living organism.

The rooms were built using a wattle and daub system, reviving ancestral techniques using earth and natural fibers that had been displaced by high-impact industrial models. The earth used in these walls comes entirely from the same site where the house was built, reducing transportation and embodied energy, and reinforcing a direct relationship between architecture and place.

The clay and hydraulic lime finishes provide thermal comfort, humidity regulation, and natural resistance to mold, insects, and tropical deterioration. The fired clay floors, double-brick walls, and natural stone contribute thermal mass, helping to stabilize the interior temperature and reduce the extreme fluctuations of the dry tropical climate.

Nothing here attempts to violently fight against the environment.

Everything tries to engage him in dialogue.

Even the lighting was designed with restraint in mind. Artificial over-illumination was avoided to reduce light pollution and recover the experience of natural darkness and biological cycles that contemporary architecture often ignores.

The saltwater pool reduces the use of harsh chemicals, and the landscaping uses species adapted to the Guanacaste drought and with low water consumption, understanding that design also implies respecting future water scarcity.

But perhaps the most important thing about this house is not just the final result.

It’s the process.

Every detail involved recovering artisanal knowledge that has been slowly disappearing: working with earth, lime, bamboo, stone, and passive systems. These are crafts passed down through generations and then displaced by accelerated, industrialized construction that is highly dependent on energy.

This house is a commitment to that transition.

An architecture where tradition and technology do not compete, but collaborate.

Perhaps for a long time we were led to believe that building better meant building more industrially, faster and more standardized.

But the future probably needs exactly the opposite:

more passive intelligence, more living materials, more human hand, more local knowledge, and more climate sensitivity.

This house in Guanacaste is not meant to be perfect.

It aims to open a conversation.

A conversation about how we want to inhabit the planet in the coming decades.

And about how architecture can still be a tool for regeneration, beauty, and balance.

The Canadian well system implemented in the house functions as a passive method of heat exchange with the earth, taking advantage of the temperature stability that exists below the surface of the ground.

The system consists of an underground duct approximately 45 meters long and 30 cm in diameter, buried about 2.5 meters deep. At that depth, the soil temperature remains much more stable than the outside temperature, especially during the hottest hours of the day.

Outside air circulates through this buried duct and, during its journey, exchanges heat with the ground. When the outside weather is very hot—as is often the case in Guanacaste—the air cools down a few degrees before entering the house. Interestingly, the higher the outside temperature, the more noticeable the cooling effect of the system becomes. At night, when the ambient temperature drops and approaches the temperature of the ground, the thermal effect becomes more subtle and balanced.

The main duct leads to a central junction box, from which air is distributed through 3-inch PVC pipes to different areas of the house. Each room has 12-volt exhaust fans that can be activated individually, allowing fresh air to be drawn in as needed.

Although the system is not intended to replace conventional air conditioning, it does help reduce indoor temperatures and decrease reliance on energy-intensive mechanical systems. Furthermore, it forms part of a broader bioclimatic strategy based on cross ventilation, thermal mass, and natural materials.

This Canadian well should also be understood as a pilot and experimental system. Beyond its current results, the project seeks to continue investigating and refining aspects such as thermal efficiency, airflow, energy consumption, and acoustic insulation within the ducts.

Part of the value of this type of architecture lies precisely in experimenting again with passive systems adapted to the territory and local climate, instead of relying exclusively on standardized industrial solutions.