Sustainable construction starts with public toilets: the project in Sri Lanka

“The Lanterns”: Here's how toilets and latrines of a Sri Lankan school illuminate the future of sustainability in construction globally

Sustainable construction: a project that starts from public toilets
The new bathrooms at Dharmaraja college in Kandy, Sri Lanka, are the result of 20 years of research on sustainable construction (Photo: EPFL/RAW Robust Architecture Workshop)

When you think about thebuilding planet examples of great architecture immediately come to mind such as the Bosco Verticale by Studio Boeri or the New SANAA Campus of the Bocconi University in Milan. Urban regeneration, however, can also happen through popular structures and in common use such as public toilets, and can give life to economic structures, livable and built with local and sustainable materials.
The draft Paolo tombesi e Milinda Pathiraja was born precisely with this objective: to demonstrate that the design planet can also deal with the economic feasibility of projects, and bring new life to the construction sector of countries in economic transition.

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Sustainable and economical construction: the project in Sri Lanka
Urban regeneration in developing countries starts from the public toilets of Sri Lanka: the Swiss project of the Federal Polytechnic of Lausanne (Photo: EPFL/RAW Robust Architecture Workshop)

Sustainable construction must start with truly essential infrastructure

Paolo Tombesi and Milinda Pathiraja met for the first time in 2010, at the University of Melbourne: then Professor Tombesi, who today is Director of Construction and Architecture Laboratory (FAR) of the Federal Polytechnic of Lausanne in Switzerland, was a professor of Construction at the Australian University, and supervised Pathiraja's degree thesis.

The student's work focused on the possibility of using real architectural design to define the building policies in developing economies, a field of study that is al research center most recent of Professor Tombesi on the subject of sustainable building.

Their project, which is based on the acquisitions of twenty years of research on industrial restructuring, was inaugurated on 14 July 2023 in Kandy, a city in the heart of Sri Lanka: it's called “The Lanterns” and it's the new bathroom of Dharmaraja College, Milinda Pathiraja's old school.

"Construction activity in transition economies such as Sri Lanka is fragmented into markets with different economic and cultural capacities”, says Pathiraja, who will be a visiting fellow at the Construction and Architecture Laboratory (FAR) ofEPFL until spring 2024.

"Essential social infrastructure such as public toilets are usually positioned at the bottom of the value scale", explains, "but if strategically planned, the design of such infrastructures can be used as an opportunity to spread innovation and introduce practice-based stimuli for the necessary revival of local building culture".

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The concrete shell of the vault of the new public toilets in Kandy, Sri Lanka: a concrete example that aims to inspire the entire sector (Photo: EPFL/RAW Robust Architecture Workshop)

Lanterns: the ideal urban regeneration in transition economies

The two blocks that give shape to The Lanterns project are apparently very simple: the roof is made up of two vaults ferrocement and the exterior walls are assembled from perforated concrete blocks. Where before there were dirty and suffocating concrete walls, there is now a spacious, well-ventilated environment illuminated by natural light.

"We have received very positive feedback since the new toilets opened“, says Pathiraja. “The industrial design ambitions of our project fit well with the improvements we have achieved in environmental performance and comfort".

What Pathiraja and Tombesi have been working on for over twenty years has a common goal: to combine practice and research for test concretely the hypotheses capable of improving industrial planning in transition economies.

The Kandy toilet blocks represent the latest, and so far most developed, application of their strategic ideas and are particularly relevant to the challenges the country is currently facing.

"Our pilot project wasn't just about building toilets”, says Pathiraja. “It also gave us the chance to demonstrate that it is possible to design and build in sustainable way in Sri Lanka taking into account the industrial conditions, challenges and expectations of the country".

"The language of the concrete components used in our project", explains, "aims to find the right balance between organized construction practices from industry and craft and cultivate new economically sustainable and ecological building 'traditions' for countries subject to urbanization pressure, limited raw materials and financial constraints. "

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The manpower provided to the project by the Air Force at work: for sustainable construction to truly spread, it is necessary to transmit skills and exploit local materials (Photo: EPFL/RAW Robust Architecture Workshop)

Sustainable and local construction at the price of just $400 per square meter

The constraints were clear from the beginning of the project: given the sad state of the economy of Sri Lanka, researchers had to be cost-conscious. As Pathiraja explains: “Sri Lanka is currently going through a economic crisis leading to a depletion of its financial reserves, a decline in construction activity and a drastic decline in material imports".

A complex but also stimulating challenge: “This is opening up opportunities to bring back construction know-how post-independence”, explains Pathiraja, “particularly regarding local prefabrication methods”. Furthermore, this situationencourages the use of local materials with a smaller carbon footprint".

Le local resources they have in fact replaced the most common construction materials, such as aluminum and glass, which require global supply chains and which consume a significant amount of gray energy (i.e. that needed to produce, to carry and dispose of a product).

The real challenge here is to develop asustainable construction that is accessible and affordable"For example, ferrocement vaulted roofs combine cost efficiency, ease of maintenance, ease of aging and low material content with improved water collection, volumetric feel, chimney ventilation and vandal resistance”, explains Pathiraja.

"Our as-built toilets”, explains Professor Tombesi, “meet rigorous design standards and manage to keep the overall cost down to $400 per square meter, including sanitary appliances".

"Given the need for this type of program across the country, it is likely that the lessons we have learned will be taken up by others”, concludes Tombesi.

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Urban regeneration: the Swiss project in Sri Lanka
Urban regeneration and the challenge of economic feasibility: the EPFL project in Sri Lanka (Photo: EPFL/RAW Robust Architecture Workshop)

Kandy's public toilets as a real stimulus for more sustainable construction

The new toilets, called "The Lanterns" not by chance, aim to be a light capable of inspire the entire construction sector of the country, and beyond. Sri Lanka, in this sense, will be the launching pad for a much larger research project.

Between now and 2024, Pathiraja will work with Tombesi on an analysis of life cycle of commercial structures conventional ones built in recent years along the arterial roads of Sri Lanka. The results of the investigation will then be compared with those that would have been obtained by applying the construction approach of the Kandy baths. The objective is to demonstrate that the right industrial strategies can be competitive in terms of architectural quality, costs and environmental impact.

The dynamics being experienced in Sri Lanka could soon be applied to other regions of the world. The idea that sustainable building practices can be stimulated starting from the public bathrooms of a high school may seem like an ambitious project, but the two researchers are optimistic: “A global journey begins with small steps at the local level”, says Tombesi.

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Sustainable construction: the bathrooms of Doctor Milinda Pathiraja's old high school become a global example of sustainable and economical construction
The bathrooms of Doctor Milinda Pathiraja's old high school become a global example of sustainable and economical construction (Photo: EPFL/RAW Robust Architecture Workshop)