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.
CIAT reflects on the party conferences.
CIOB announce the winners of the Art of Building photography competition.
National Scheme of Delegation introduced.
The cost of employing people remains a concern.
Code of Practice for Electrical Energy Storage Systems.
ECA calls on members to comment on draft 4th edition.
Bringing together expertise and creating cultural benefits.
CIOB celebrates positive Ofsted report.
The Building Safety Regulator announces a call for evidence.
Government approach could undermine delivery and regeneration.
World's first mass timber data centre.
The overlooked environmental aspect of data centre development.
Introduction to radon awareness
New technical information sheet published by CIOB.
Updated supplier guide can help electrical contractors engage with NHP.
















