Total solar irradiance
Competence frameworks for the built environment – Core criteria for sustainability competence - Code of practice , Version 3, published by the Edge for the Construction Industry Council in February 2025, defines total solar irradiance (TSI) as: “The total amount of solar radiation in watts per square metre received outside the Earth’s atmosphere on a surface normal to the incident radiation and at the Earth’s mean distance from the Sun. Reliable measurements of solar radiation can only be made from space, and the precise record extends back only to 1978. Variations of a few tenths of a percent are common, usually associated with the passage of sunspots across the solar disk. The solar cycle variation of TSI is of the order of 0.1%.“
See also: Insolation.
[edit] Related articles on Designing Buildings
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
The Master Builder: William Butterfield and his times. Book review.
Why construction can't afford to ignore the skills gap.
Building Safety Regulator, 19 August
Gill Kernick appointed Independent Chair of Residents’ Panel.
Connecting knowledge, technology and conservation
Building competence for the future of built heritage.
Building Regulations and Building Safety Act
CIOB publishes free advice for non-domestic clients.
Building Safety Newsletter from MHCLG.
An extraordinary record of steel engineering worldwide.
Households living near new pylons to save on bills.
ECA warns growth must not outpace grid capacity or skills.
The role of the client and decision making
CIOB response to built environment professions call for evidence.
Construction's sustainability reporting revolution
Tracking upfront embodied carbon with digital tools.
ECA welcomes procurement reforms
Public spending must back British jobs and skills.