Interpretation of the archetype:
the Nubian vault
this is the first step of a long journey
Airchitects hosts people with various background. They are very passionate about what they study and work on. So we decided to start to share pills and details about one of our beloved specialities: earth based vernacular architecture.
Nowadays vernacular means domestic, familiar. The word comes from the latin vernaculus. It meant ‘an attribute of a slave (verna) born in the house of the owner’. It sounds strange because vernaculus did not have a Latin origin, but its roots come from the Sanscrit language. An ancient western Asian language. More precisely it comes from the word vasna that means house or robe. That explained also why for an ancient Roman vasna, that was a word used by some slaves, is related to both slave and house.
The digression was necessary. We are going to talk about things that have their origins lost at the dawn of time. Knowing this, it will be better to ask Paul Oliver to help to expose the concept in a suitable modern way:
" Vernacular architecture can be said to be 'the architectural language of the people' with its ethnic, regional and local 'dialects' "
Vernacular architecture is strictly related to people and their history, memory and heritage. It is the culture at the state of the art. Therefore, is not possible to decide not to take a deep dive into it. It is not possible for an architect to decide to not contemplate a re-interpretation of The Archetype.
the nubian vault
The Nubian vault technique dates back to 3000 years ago. Archaeological traces have been found between upper Egypt and the Sudan northern region (Ramesseum temple and Luxor). The technique is essential, effective and requires a bit of knowledge and pure earth.
- Earth conglomerate
- Cocked earth bricks
- Earth conglomerate
- Cocked earth bricks
With few more materials and tools is possible to be more creative with the design, accessing to various levels of customization. Nubian vault are adaptable to suit the needs and financial resources. At this point it is a matter of finishings, depending if we want to design a hospital in Sudan or a mansion in Arizona.
Phase 1: Location Location Location
Yes, this is the real estate mantra echo. Anyway, in this case, the location does not affect only prices! It is essential to choose a site that is not in danger of seasonal flooding.
Phase 2: gathering the necessaire
It is time to gather all the material on site. If it is necessary is also the moment to start to cook bricks.
Phase 3: Foundations
Depending on the properties of the ground and the site of the building, foundations can vary from 40 to 80 cm deep; they need to be 70 cm wide for load-bearing walls and 50 cm wide for the gable walls. They are filled with rocks, bound with an ordinary mortar.
Phase 4: Elevation
Load-bearing walls which carry the vault are 60cm thick, and are made up of rows of super-imposed mud bricks. Recesses and openings are built into the thickness of the walls. These are headed with arched lintels buit with temporary support.
Phase 5: Construction of the vault
It is possible to proceed without shuttering to support the vault during construction. Workers just need a mortar to start laying the first course of bricks along the ones that compose the gable wall. In order to define the central axis of the vault is possible to stretch a cable between the two gable walls. Then, it is possible to use a cord fixed to a sliding ring on the cable as a reference in order to maintain a constant radius for the vault. Towards the top of the vault, it is possible to add a couple of fingers width to each joint to develop an ogival shape. Finally, the roof is water-proofed, using plastic sheeting, over a smooth coat of mud mortar. It is important to cover the sheeting by a rendering of enriched mud mortar, to protect it from the sun and avoid degradation.
Sustainability and viability
The main material is earth, that is almost available everywhere on the Earth. That means no transportation and low carbon dioxide emissions. Plus, no tree needs to be cut!
The materials that are used are excellent thermal and acoustic insulants. Insulation costs lots of money.
Applicable to a wide range of buildings (houses, schools, healthcare…), which are easily extendable.