We typically provide a lighting level survey of the existing illuminance and a technical report to summarise our findings. The report will identify a suitable lighting class for the installation and we compare our findings against the standards identified. We’ll also provide our professional opinion on the installation, as well as tips on how to improve your existing scenario, which may cover energy saving measures, glare reduction, light spill control, electrical recommendations, the addition of colour and smart switching arrangements. We may also be able to provide advice and guidance on how your installation could generate a passive income for you.

The simple answer is to ask us! But we also know that you might want to find this out for yourself. There are guidance notes on this (specifically GN/01: The Reduction of Obtrusive Light, which is from the Institution of Lighting Professionals and supported by many other documents). The key thing to remember assessing the environmental zone for your project is how it might be influenced by surrounding areas to your project and their environmental zones.

It doesn’t! Too often, people just light something because they think they should. Then they ask for a quick mock up from suppliers to get some quantities. This often leads to basic lighting schemes that use more products and energy than what’s required. When you employ a lighting design consultant like us, we’ll make sure you only light what needs to be lit and with the least amount of equipment and light needed. So, we get the right light in the right place at the right time.

We can’t change the laws of physics (yet!), but we can choose the best luminaire and put it in the best position to maximise the useful light and minimise the light spill. We can tell you where the spill light will be, horizontally and vertically, and explain what effect it’ll have — if any. It might sound obvious, but its our job to make sure we only put the lighting where you need it.

CCT stands for correlated colour temperature and is scored in Kelvin (K). The lower the number (or the K), the more red the light will look. The higher the number, the whiter or bluer the light looks.

Street lighting should normally be pitched around the 2700-3000K mark, but every site or project should be assessed individually.

We’ll keep this one simple.

Lumens (denoted by lm) are a measure of the total amount of light from a lamp or other light source that’s visible light to the human eye. The higher the lumen rating, the brighter the lamp will appear.

Lumens per watt (lm/W) refers to the energy efficiency of lighting, meaning how much visible light you get for a given amount of electricity.

Lumens per circuit watt (lm/cW) is the power consumed in lighting circuits by luminaires and, where applicable, their associated control gear (including transformers and drivers) and power factor correction equipment.

DarkSky International (formerly the IDA) is the International Dark Skies Association. This organisation works hard to promote dark skies, which can be disturbed by poor lighting design and products that produce lots of unwanted light in the nighttime environment. We, as responsible lighting design constancy, share this commitment to dark skies — working hard to minimise as much obtrusive light as possible with our work. We feel it’s our responsibility to make sure we design in a way that is considered, environmentally conscious and sustainable.

IP stands for ingress protection. An IP rating relates to the amount of water, dust particles or objects that might enter the product in any given direction. Typically, the higher the rating the more resistant to water and particles the product is. The biggest issue you might see in exterior lighting is when interior products or floodlights are installed in external locations.

In exterior lighting the word ‘photometry’ relates to the the light output from a specific product and how it falls on the road. With different lumen packages and optics, each option and output should have its own unique photometric file. Sometimes, photometry may be described as relative or absolute. Absolute photometry is always the most accurate!

An LPA is a local planning authority. These are the teams that will approve your wider project or scheme or sign off any lighting conditions you need to satisfy.

We’ll try to be to the point with this one. A lighting strategy talks about how the lighting you plan to install will follow a palette of materials and stay in keeping with the development or surrounding area — referencing the standards and guidance the design principles will follow. A technical report’s a way of demonstrating what a proposal or existing installation is achieving and how that relates to standards, with a professional conclusion presented at the end. Finally, a lighting impact assessment looks at what the impact of the proposed lighting will have on the development when considering the current baseline conditions.

Yes we do! DFL’s committed to ensuring our lighting designs are environmentally friendly, so we complete our lighting designs and specify light sources in accordance with the Institution of Lighting Professional’s Guidance Note 08 (Bats and Lighting in the UK).

At DFL, we like to give clear advice — and we advise against using bollards to light roads. That’s because we wouldn’t generally be able to light the road to a recognised standard with illuminated bollards. These lights are generally designed for paths or wayfinding purposes only, where there isn’t a need to spread the light across a wide area. They can also be a source of glare to drivers, which could in fact reduce the safety of your road. Our advice is to steer clear and go for columns as we can use less units whilst providing a higher quality of light. It’s a win-win!

Processes for obtaining technical approval for lighting can vary depending on the local authority. Generally speaking, DFL will design your lighting in accordance with the local authority’s design guide whilst liaising with the authority on the lighting levels we’ve selected. We’ll then send the design off to the authority for them to either comment on and later approve.

Our designers work with computer-aided design (CAD) drawings to ensure the proposed lighting equipment fits within the site, and we use utility stats to ensure we avoid proposing equipment in the vicinity of underground or overhead utilities. This is all part of our duties under the Construction Design and Management Regulations (CDM 2015), which make sure our proposals are safe and do not endanger those who will install, maintain or decommission the equipment by proposing to install a piece of equipment too close to a hazardous utility.

Because we only produce quality designs! With professionals who are suitably qualified and competent in their field (i.e. lighting and electrical), we can abide by our assurance that our projects are delivered to the highest possible standards every time. Our staff have to work incredibly hard to achieve these Engineering Council registrations, so you can rest assured that the teams delivering your project really know their stuff!

Maintenance factors are used to account for the dirt that might build up on light fittings, as well as the depreciation of the light output of the fitting over time. They give us a factor to apply to the design to ensure that the light levels that are achieved on the ground are exactly as intended and still comply with British Standards at the end of the installation’s life. If we are working with you on a lighting impact assessment (LIA) or bat-sensitive project, we’ll generally apply a Maintenance Factor of 1. This shows the people who need to know that we have accounted for the worst case scenario, such as the brightest light levels when the light fittings are shiny and new.