The 7-Step Programme to Good Lighting: Step 3 – The Specification

I’m in a hotel room and have just finished what was laughingly called ‘a breakfast box’. There is a yawning gulf between what was in my head and what was in the box. In a positive glow of expectation, I was seeing a fresh croissant, perhaps a small pot of strawberry jam – maybe a tub of yogurt and a bite of fruit. Imagine my surprise . . . a pot of cornflakes, orange juice concentrate and an embarrassed-looking fairy cake. I never checked the specification, you see. If I had, I’d have gone down the road for a bacon sandwich and a mug of tea.

So what should we be looking at when it comes to a lighting specification? Let’s look at why this is a problem.

RefA:     A 600x600mm slimline LED panel; 4000K colour temperature; 3000lm output.

Now we can all picture what that fixture looks like, but it also lets in the ‘Breakfast Box’ version of the same thing. The cost of that fixture ought to start around £40.00, but we know that the specification can be met by going on-line and buying a ‘compatible’ fixture for less than half of that. But few (none) of us would want to see any of those fixtures in our projects.

Let’s look again at that specification:


A 600x600mm slimline LED panel
Flame-resistant Tp(a) opal diffuser
Back-lit LED array

Light performance:
Colour temperature: 4000K
Colour rendering: >80CRI
Light output (from fixture): 3000lm
Effective working life (L70): 50,000 hours

Electrical specification:
Driver: constant current operation; non-dim
350mA output current
>90% circuit efficiency
Nominal life-time operation >50,000 hours
5-year guarantee
Power Factor >.9

See what we did there?

There’s nothing in this listing that can’t be lifted from a good-quality luminaire datasheet, and there are certainly factors that can be added, according to project needs. The difference is that, every time another line is added to a specification, its like adding a brick in the protective wall that keeps the bad stuff away. It isolates those bottom-feeders who would seek to pervert lighting design outcomes in their shark-like, amoral, pursuit of profit.

This article is aimed at those in the lighting community who are responsible for preparing product specifications for design projects. And we (and I mean WE) are not working hard enough to ensure that design quality, which is generally high, is sustained once the specification documentation leaves our desks and moves into the supply/install route. We’re probably not arguing our position with sufficient vigour with the client/project leaders. If I specify a fixture, I know what it is that I’m trying to achieve; once that specification shifts to a third party I must not assume the same level of intellectual ownership (or due diligence) of that specification. Its that disconnect that opens the door to the Value Engineering debacle that ruins so much of our work. We have to fight for continued oversight of a project beyond the documentation handover.

And another thing: further along the 7-Step Programme we look at the Commissioning and Hand-over. At the moment we’re obliged to work within a not-fit-for-purpose ‘equal and approved’ regime. The backstop, if all other attempts to control specification have failed, is that the commissioning agent has the ability to look back at the design specification – take a look at the installed product datasheet – and condemn anything that’s been allowed to sneak in via that discredited hole in the wall.

There are new initiatives that suggest that the general atmosphere around this is changing in our favour. The most important shift will probably turn out to be a couple of new announcements from the RIBA. The Quality Tracker (jointly by RIBA, RICS and CIOB) is intended to provide an overview of project progress by establishing a ’chain of custody’. It means that real people, who can be pointed at, can be held responsible for specification infringement. The other announcement, from the RIBA is its declaration of an environment and climate emergency. The Ethics and Sustainable Development Action Plan Architects are now obliged to look closely at the sustainable credentials of materials and equipment that will be used in their buildings. That MUST impact on the character of specifications from all specialist consultants. It will call for far more detailed specification documentation than I’ve been writing about here. And those two things brought together will surely help to protect the quality of all design input across a building project.

Hasten the Day!



This article is one on the series of Good Lighting pieces for The Light Review.

Posted in ,
Find out more:

The Light Review Newsletter

* indicates required

Please confirm you'd like to hear from The Light Review by email:

You can unsubscribe at any time by clicking the link in the footer of our emails. For information about our privacy practices, please visit our website.

Latest Articles

Scroll to Top