Building with raw earth in Morocco, or why the oldest material is again the most relevant.

Architecture without architects

Vernacular architecture is architecture without architects. It is the architecture of our forebears, before modern planning existed.

Jaafar Sijelmassi — Medi1, November 2024

This is not naive building. It is the product of empirical knowledge accumulated and passed down through generations: you know not to build on this spot; you know that this material paired with that one yields a given strength and a given thermal behaviour. An architecture born of common sense, of the hand, and of constraint — making do with what is there.

Not one Moroccan tradition, but several

There are as many vernacular architectures as there are regions. Each solved a local climate equation with the resources available within a day's walk.

Medinas: climate control at city scale

In the historic walled cities, the strategy operates at urban rather than building scale. Narrow streets shade one another. Houses turn inward, with few openings to the outside, organised around a riad — a central garden courtyard. At its centre a fountain, whose evaporation produces natural cooling, distributed through the surrounding galleries by planting and cast shade.

Why earth, and why now

Among all the ways of building with earth — rammed earth, adobe, cob — it is the compressed earth block that best meets contemporary requirements for comfort and insulation, while remaining compatible with the specifications of major corporate clients.

When we dig, instead of treating the soil as waste, we treat it as a noble material that simply needs shaping. What we took out of the ground goes into our walls.

Jaafar Sijelmassi — Medi1, November 2024

This changes the economics of a site. Every project excavates for its foundations; that soil normally goes to landfill, with the haulage cost and carbon footprint that follow. Reusing it in the walls eliminates two flows at once.

Thermal mass, explained by the kasbahs

An earth wall does not work as insulation — it works as a thermal flywheel. It creates a time lag: by the time heat has travelled through the wall, the day is over. This is why the interior of a kasbah, a fortified earthen residence of southern Morocco, stays moderate while outside conditions are punishing. And at night, when outside temperatures fall towards zero, the heat stored in the mass is released back inside.

Two further properties are rarely mentioned: earth regulates interior humidity automatically, and it emits no volatile organic compounds — which sets it clearly apart from construction systems based on resins and adhesives.

Material drives form

We say form follows function. What I learned in practice is that it is the material, the environment and the climate that drive form.

Jaafar Sijelmassi — Medi1, November 2024

The medina house is square or rectangular, highly symmetrical, with right angles — because it is simpler to structure the material that way than to produce curves. Elsewhere, different constraints produce different geometries: the circular dwelling, whose trace survives in the language itself — dar, the house, and douar, the circle. The igloo follows the same logic: one available resource, and a form that follows mechanically from it.

This is not determinism, it is convergence. The harder you pursue efficiency, the closer you come to a type-solution for a given climate and a given material.

Three passive ventilation devices

The malqaf

A wind catcher mounted on the roof, related to the Iranian badgir. Oriented into the prevailing wind, it channels air down into the building with no energy input.

The matfia

An underground rainwater cistern beneath the house. Routing air through this volume produces evaporation that cools the flow before it reaches the rooms.

The venturi effect

High-level openings of unequal section — wide on one side, narrow on the other — to accelerate airflow and create suction that clears stagnant air under the roof.

Neither nostalgia nor headlong flight

We are not anti-modernity or anti-technology radicals. What we are trying to do is find the right balance between low-tech and high-tech.

Jaafar Sijelmassi — Medi1, November 2024

On one side: ancient bioclimatic principles, materials sourced within a hundred kilometres, and the deliberate choice to employ local labour rather than import components whose embodied energy and maintenance weigh heavily.

On the other: centralised building management, motorised opening actuators, and a network of sensors for humidity, temperature, wind, occupancy and light levels. The building then sits somewhere between a living organism and a computer: it opens its windows according to the hour and the state of the air, and adjusts its consumption continuously.

Combined, the two approaches do not aim at carbon neutrality. They aim at a building that produces more energy than it consumes.

Africa has a card to play

Our continent may well have a card to play in the architecture of the future.

Jaafar Sijelmassi — Medi1, November 2024

The argument is practical rather than identitarian: the link to ancestral building knowledge has not been severed here. Where other continents must rediscover these principles through research, part of African society retains both the memory and the gestures.

This is the lineage the practice claims — that of architects such as Diébédo Francis Kéré, the first African recipient of the Pritzker Prize, and Kunlé Adeyemi, who built a contemporary practice from local materials and local know-how. Not to go backwards, but to modernise what already worked.

Architecture has the power to transform lives and connect people to their cultural roots. By integrating traditional methods and modern technologies, we can create buildings that respect the environment and answer the needs of communities.

David Adjaye, architect (Ghana) — quoted in Archibat No. 63

One qualification, set out in the same article: having long been advocates of degrowth, we now understand that evolution beats revolution. The aim is not to renounce development, but to find the right balance between uncompromising ecology and a legitimate need to build — adopting the latest techniques while avoiding the traps of overconsumption.

The Bosch case: the proof

Bosch's regional headquarters in Casablanca is where this method was pushed furthest, at the scale of a major German industrial client. Delivered in 2024 after two years on site, it totals 12,381 sq m net and 240 workstations.

The earth was excavated on site, then selected, sorted and put through a series of laboratory tests. Once the mixes were validated, sample panels were built before final execution. Two laboratories, an environmental engineering consultancy and a receptive contractor were mobilised on that single aspect.

What the numbers say

• Rammed earth columns 14 metres high and CEB walls 50 cm thick.
• Earth thicknesses of 50 to 100 cm depending on the wall.
• Under 7% lime or cement in total across the mixes.
• South façade in rammed earth acting as a heat storage battery, animated by adjustable solar shading.
• CEB façades regulating temperature, but also humidity and air pollution.
• Water-fed radiant ceilings, avoiding conventional energy-hungry air conditioning.
• Night cooling by venturi effect: motorised openings cool the slabs overnight, before staff arrive.
• Fully photovoltaic roof, producing more energy than the building needs — battery storage and electric vehicle charging.
• Sensors for temperature, light, humidity, wind and pollution, driven by a centralised building management system.
• BIM model connected to the nearest weather station, to simulate thermodynamic behaviour and cross-ventilation.

A language, not only a technique

Working with earth also allowed a contemporary reinterpretation of the architectural language of the ksour — the fortified earthen villages of southern Morocco: their crenellations, vertical openings and inward-facing rectangular plan. Inside, a riad shelters the building from the outside — a semi-tropical garden planted in open ground, an aromatic living wall, and a zellige-tiled fountain that cools the air, in the architect's phrase, "naturally and musically".

And an outcome rarely expected from a corporate project: relying on pre-industrial techniques made it possible to employ three times more workers and craftspeople than a conventional build.

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