Eaves
Contents |
[edit] Introduction
Eaves are the part of a roof that projects out horizontally beyond the side of the structure it covers. They can have practical functions, such as to provide shade and protection from rain, as well as aesthetic functions, creating a definite distinction between walls and roof.
Typically, the eave’s width is related to the roof pitch. The steeper the pitch is, the narrower the eaves.
[edit] Types of eaves
There are four basic types of eaves:
- Exposed: The finished underside of the roof and supporting rafters are visible from underneath.
- Soffited: Includes a soffit – the panelling which forms the underside of the eaves, connecting the bottom tip of the eave with the side of the building at a 90-degree angle.
- Boxed-in: Encases the roof rafters but meets the side of the building at the same angle as the roof pitch.
- Abbreviated: Cut off almost perpendicular with the side of the building.
Most types of eaves include a fascia, which is a horizontal board that runs around the edge of the eaves to cover the ends of the extended rafters.
Exposed, soffited and boxed-in eaves generally include air vents to ventilate the roof space or roof structure, preventing the accumulation of moisture and so reducing the likelihood of condensation forming. Eaves can also incorporate guttering, which conveys rainwater run off from the roof to a drainage system.
[edit] Purposes of eaves
Eaves prevent rain, snow and other debris from causing leakage-related damage to the building facade, by directing it out and away from the building.
Eaves can also provide shading to windows, helping to maintain comfortable internal conditions. In the winter, low-level sun is able to penetrate windows to warm and light the interior, whereas in summer, the projecting eaves prevent direct sunlight from entering the building.
They can also be used to help define the architectural style of a building. For example, Dutch Colonial houses featured flared eaves that curved up and away from the roof; the architect Frank Lloyd Wright often used sweeping, elongated eaves in his Prairie house designs; and traditional Asian pagodas are defined by tiers of multiple eaves. A-frame houses include eaves that can reach ground level. A characteristic element of the Italianate style is buildings with decorative, overhanging eaves on a slightly pitched roof.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
BSRIA Statutory Compliance Inspection Checklist
BG80/2025 now significantly updated to include requirements related to important changes in legislation.
Shortlist for the 2025 Roofscape Design Awards
Talent and innovation showcase announcement from the trussed rafter industry.
OpenUSD possibilities: Look before you leap
Being ready for the OpenUSD solutions set to transform architecture and design.
Global Asbestos Awareness Week 2025
Highlighting the continuing threat to trades persons.
Retrofit of Buildings, a CIOB Technical Publication
Now available in Arabic and Chinese aswell as English.
The context, schemes, standards, roles and relevance of the Building Safety Act.
Retrofit 25 – What's Stopping Us?
Exhibition Opens at The Building Centre.
Types of work to existing buildings
A simple circular economy wiki breakdown with further links.
A threat to the creativity that makes London special.
How can digital twins boost profitability within construction?
The smart construction dashboard, as-built data and site changes forming an accurate digital twin.
Unlocking surplus public defence land and more to speed up the delivery of housing.
The Planning and Infrastructure Bill
An outline of the bill with a mix of reactions on potential impacts from IHBC, CIEEM, CIC, ACE and EIC.
Farnborough College Unveils its Half-house for Sustainable Construction Training.
Spring Statement 2025 with reactions from industry
Confirming previously announced funding, and welfare changes amid adjusted growth forecast.
Scottish Government responds to Grenfell report
As fund for unsafe cladding assessments is launched.
CLC and BSR process map for HRB approvals
One of the initial outputs of their weekly BSR meetings.
Building Safety Levy technical consultation response
Details of the planned levy now due in 2026.
Great British Energy install solar on school and NHS sites
200 schools and 200 NHS sites to get solar systems, as first project of the newly formed government initiative.
600 million for 60,000 more skilled construction workers
Announced by Treasury ahead of the Spring Statement.