Lighting efficacy
Rules of Thumb, Guidelines for building services (5th Edition) BG 9/2011, by Glenn Hawkins, published by BSRIA in 2011, defines lighting efficacy as: ‘The amount of light (luminous flux) produced by a light bulb or other light source, usually measured in lumens, as a ratio of the amount of power consumed to produce it, usually measured in watts.’
BG 87/2024, Useful Information Guide, written by Chin Hang “Kay” Lam and published by BSRIA in 2024, defines lighting efficacy as: ‘A measure of how much light a light source produces for the energy put in to it. This is normally expressed in lm/W (lumens per watt).’
--BSRIA
See also: Lamp efficacy.
[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.
Confronting competency, codes, capacity and costs.
The hidden risk in modern construction supply chains.
Construction Management, 10 June
24 months to 14: CITB launches accelerated apprenticeships.
Bridging the gap between clients and contractors
Concerns remain around contractor quality, capability, and delivery.
Construction Management, 10 June.
Heat pumps beat boilers in new home tests.
Building Safety Act implementation in Wales
CIAT to host industry panel on 26 June.
New and updated CLC building safety guidance.
New UK National Buildings Database.
Building Safety Wiki Interviews
Chief executive of the British Woodworking Federation.
Planning condition discharge in England and Wales
A brief explanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
















