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.
Undervaluing our industrial past
Heritage value changes as taste for building styles changes.
Changing expectations around competence and compliance
New information sheet from CIAT.
Grenfell investigation files passed to CPS
Angela Rayner apologises on behalf of the British state.
Electrical contractors need to understand the practical implications.
The real barrier to getting more value from digital technology.
Your guide to The Construction Reset at UKCW Birmingham.
Accommodating the Victorian and Edwardian working woman. Book review.
Rethinking passive fire protection in design
PFP demands the same level of design rigour as structure or services.
38% of Gen Zs feel safe when a fire door is wedged open.
Stunning images from around the world
Shortlist for CIOB’s Art of Building photography competition.
Guidance for conversion of traditional pre-1919 stone buildings.
Industrial heritage in the Ruhr
A marked difference to the fate of industrial landscapes in the UK.