Planning a facade lighting scheme

The short answer

Good facade lighting starts with the building, not the luminaires. Decide what the building should look like at night and where it will be seen from, light the features that carry that idea, and leave the rest in shadow. Then choose positions you can actually fix to, power and reach for maintenance, and set controls so the lights are on only when they’re useful.

If you’d rather talk it through, send us what you have and we’ll help from the first sketch.

1. Survey the building

Before choosing products, find out what is really there:

• Materials and colours: stone, brick, render, glass, timber and metal all react differently to light. Dark or polished surfaces reflect much less light back to the viewer than pale, matt ones.
• Texture and relief: cornices, columns, window reveals, rustication and brick bonds are what grazing light brings out.
• Fixing surfaces: where luminaires and cables can be fixed, and where they can’t (for example on listed fabric or thin cladding).
• Existing light: street lights, shop fronts and neighbouring buildings set the background brightness your scheme will be seen against.
• Power and access: existing supplies, distribution boards, cable routes, and how the building is accessed for maintenance.

Visit after dark if you can.

2. Set the intent

Write down in a sentence or two what the lighting is for: making a building recognisable from a distance, showing off its stonework, making an entrance easy to find, or marking a civic building for events. A clear intent makes every later decision easier, including what not to light.

3. Viewpoints

List the places people will see the building from: the approach road, a square, the far side of a river, upper floors of nearby buildings. Light for the main viewpoints first. Check that luminaires won’t be visible as bright points from those viewpoints, and that nobody will look straight into a beam, including drivers and residents opposite.

4. What to light and what to leave dark

Contrast is what makes a facade read at night. Lighting every surface evenly tends to flatten a building and uses more energy. As a starting point:

Light	Usually leave darker
Vertical features: columns, piers, pilasters	Large plain areas of wall
Cornices, parapets, rooflines	Glazing (it reflects little light and can cause glare)
Entrances and canopies	Areas next to bedrooms or residential windows
Towers, spires, clock faces	Trees and areas used by wildlife, unless agreed

5. Luminaire positions

The main options, which can be combined:

• At the base of the wall: linear grazers or in-ground uplights lighting upwards. Simple to maintain, but watch for glare to pedestrians and for upward light passing the top of the building.
• On the building: wall-mounted luminaires or linear profiles on ledges, cornices and window heads, lighting up or down a section of the facade.
• Set away from the building: floodlights on columns, nearby roofs or the ground, washing the facade from the front. Good for even light on a large flat face; needs somewhere suitable to mount them.
• Outlining: flexible LED neon or linear profiles tracing edges and rooflines.

Downward lighting, from a ledge onto the wall below, generally gives you better control of upward spill than lighting from the ground up.

6. Spacing rules of thumb

These are starting points only. A lighting calculation with the real photometric data should confirm them.

• Grazing: place the luminaire close to the wall, typically within a few hundred millimetres. Continuous linear grazers give the most even result; spaced point sources give a pattern of scallops, which can be a deliberate effect.
• Washing from the base: the further from the wall, the more even the light but the less texture you see. Space units so their beams overlap at roughly the point where they reach half intensity.
• Floodlighting from a distance: a wider beam and a greater distance give a more even result. Check that the beam isn’t wider than the facade.

See choosing beam angles for how height, distance and beam relate.

7. Aiming

Aim to keep light on the building. Use the narrowest beam that does the job, fit glare shields or louvres where luminaires are visible, and aim floodlights below the roofline so light isn’t thrown into the sky. Plan to adjust aiming on site after dark at commissioning, and lock adjustable luminaires in place afterwards.

8. Controls and timers

Most facade lighting doesn’t need to be on all night. A photocell to switch on at dusk, combined with a timer to switch off or dim at a set time (a curfew), is the simplest way to cut running costs and obtrusive light. More advanced schemes use DALI or DMX for scenes, colour and dimming. See lighting controls.

9. Obtrusive light and environmental zones

In the UK and Ireland the main reference is the Institution of Lighting Professionals’ Guidance Note GN01, The Reduction of Obtrusive Light. It divides locations into environmental zones, from E0 (protected, for example dark-sky places) through E1 (dark, such as national parks and rural areas), E2 (low district brightness, such as villages), E3 (medium, such as suburbs and small towns) to E4 (high, such as town and city centres). Each zone has limits for sky glow, light into windows, luminaire intensity and building luminance, with tighter limits after curfew. Internationally, CIE 150 covers the same subject.

Planning authorities often ask for this to be assessed, and in the UK facade lighting frequently needs planning consent. Check with your local planning authority early.

10. Maintenance access

Think about how each luminaire will be reached for cleaning, re-aiming and repair, and keep drivers and control gear somewhere accessible rather than buried in the facade.

What to send us

The more we have, the more useful our first response. Helpful items:

• Elevations (PDF or CAD), with dimensions and materials marked
• Photos of the building by day and, if possible, by night
• A site plan showing viewpoints, boundaries and nearby homes
• Power points: existing supplies and where new cables could run
• Any constraints: listing, conservation area, planning conditions, budget, programme
• How you want it controlled: simple on/off, dimming, or colour and scenes

Start a project and attach what you have. We’ll come back with suggested products, positions and, where useful, a lighting calculation.

Sources: Institution of Lighting Professionals, Guidance Note GN01, The Reduction of Obtrusive Light; CIE 150, Guide on the Limitation of the Effects of Obtrusive Light from Outdoor Lighting Installations.