Shell roofs are made from structural ‘skins’ where the shell material is thin in section relative to the other dimensions of the roof and undergoes relatively little deformation under load.
They are commonly used where a building interior needs to be free from intermediate walls or columns that might support a more conventional flat or pitched roof, such as; libraries, theatres, leisure centres, airport and railway terminals, and so on.
Shell roofs can be ‘flat’, but are typically curved, assuming a cylindrical, domed, paraboloid or ellipsoid shape. The curvature of shell structures benefits from the same structural efficiency as arches, which are pure compression forms with no tensile stresses. Because of their structural efficiency less material is generally needed compared to more traditional roofs. However, a restraining structure such as an edge beams is required to prevent the shell from ‘spreading’.
Shell roofs may be:
- Single shells such as the dome of the Pantheon in Rome.
- Multi-shell roofs such as Eero Saarinen’s JFK International Airport in New York.
- Reinforced with structural ribs, such as Jørn Utzon’s Sydney Opera House.
- Lattice structures, such as Norman Foster’s Great Court at the British Museum in London.
 Related articles on Designing Buildings Wiki
- A-frame house.
- Barrel vault.
- Conoid shell.
- Domestic roofs.
- Folded plate construction.
- Hyperbolic paraboloid.
- Long span roof.
- Pendentive dome.
- Portal frame.
- Suspended ceiling.
- Sydney Opera House.
- Tension cable and rod connectors.
- The history of fabric structures.
- Types of dome.
- Types of roof.
 External references
- ‘Building Construction Handbook’ (6th ed.), CHUDLEY, R., GREENO, R., Butterworth-Heinemann (2007)
Featured articles and news
Have a look at some of the most impressive concert stage designs of all time, including Pink Floyd, U2, Rolling Stones, and more...
What is the Home Quality Mark? Find out how it can help you when buying/renting a new home.
Business Secretary launches £246m Faraday Challenge to establish UK as world leader in battery technology.
Government announces new plans for regulations to improve safety and security awareness of drone users.
Read our introductory article to the various different types of fuel.
IHBC book review: Charles Barry’s monumental struggle to rebuild the Houses of Parliament.
Read about RSHP's British Museum extension which has been shortlisted for the 2017 Stirling Prize.
Read our introductory article to building a house extension.
More updates from DCMS about the large-scale testing of cladding systems and the number of buildings affected.
UandI secure resolution to grant planning consent for major new regeneration project.
IHBC article considers how heritage is dealt with when infrastructure schemes are authorised.
It was the tallest structure in the world for 3,800 years, but to this day the exact construction techniques are a mystery.
Shortlist for the industry's most coveted award announced.