The cost of buildings using arches, vaults and cupolas varies according to the materials employed, the complexity of the design and of the construction technique, the size of the structures, and the surface protection used. However, buildings employing sun-dried earth bricks (adobe) and protected with an earth render can be built at a lower cost than traditional buildings of a similar standard. In general, arches, vaults and cupolas made from water-resistant materials and protected by durable water-proofing cost more than simple buildings covered with roof sheeting, but remain less expensive than buildings with reinforced concrete slab roofs.
Building with arches, vaults and cupolas is highly labour intensive. Therefore, the technology has great job creation potential, not only with regard to construction, but also with regard to building materials production.
Foreign currency savings
The basic materials are generally available on site, and little power is required for processing them. Significant foreign currency savings are possible. Transport costs are also reduced. The investment in site equipment, centering, compass, scaffolding, is generally very small, and most of these can be manufactured locally without any major difficulty.
Crossed arches, Zaria, Nigeria
Great aesthetic potential
The many possibilities of forms, sizes, combinations of different elements and types of finishing enable highly attractive spaces to be created. Thus arches, vaults and cupolas can be used not only for low-cost housing programmes, but also for high quality, luxury dwellings.
Woodless construction project in Niger: simple but adapted structure
Limitations of use
Some local conditions can limit the benefits of building with arches, vaults and cupolas:
· rejection by the inhabitants
for cultural reasons,
· high cost of labour,
· high cost of suitable building materials,
· use in earthquake areas requires special care,
· lack of building norms.
The technology must be adjusted to a given context and the techniques must be mastered, to warrant the advantages of using arches, vaults and cupolas.