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
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.
Government responds to Mark Farmer's review of industry, rejecting the call for a levy on clients.
Peter Hansford to examine what wider lessons can be learned from the fire.
Every project is subject to uncertainty. How can construction better understand uncertainty for performance improvement?
MAD Architects reveal their designs for a futuristic campus for electric car manufacturer.
Homebuyers could borrow more with better forecasting of energy bills, according to industry consortium's new report.
Read our introductory article on carbon capture and storage.
Have a look at Frank Gehry's Binoculars Building in Los Angeles.
BRE publish new Loss Prevention Standard seeking to minimise fire risk from ducting.
How do we tell which infrastructure projects will work?
CIAT announce the establishment of a Working Group in light of Grenfell and call for contributions.
In 1900, 15% of global population lived in cities. Now it’s over 50%. Which is why we need ‘hydroinformatics’ to consume smarter.
Have a look at these competition-winning designs for a new residential development in Eindhoven.