Street lighting, columns and adoption on new estates

Street lighting on a residential scheme gets settled twice: once through the planning permission, where a condition asks for a lighting scheme, and again through the section 38 agreement, where the highway authority decides whether it will adopt the columns and on what terms. Those two processes use different standards and different officers, and a lighting design that satisfies the planning case officer can still be rejected by the street lighting engineer three months later.

Deal with both at the same time. The cost of getting it wrong is a commuted sum you did not budget for, or an estate road the authority declines to adopt.

Who ends up owning the lighting

There are three outcomes and they need deciding before the layout is fixed.

The highway authority adopts the road under a section 38 agreement made under the Highways Act 1980, and takes on the lighting with it. This is the usual expectation for through routes and for anything serving more than a handful of dwellings. The authority will require its own specification, its own approved equipment list, and often a commuted sum.

The road stays private, with lighting maintained by a management company funded through an estate charge. Common on small courtyards and on schemes where the authority will not adopt shared surfaces.

A hybrid, where the spine road is adopted and the private drives are not. Most medium-sized schemes end up here, and the boundary between the two needs drawing on the layout plan at the outset, because the lighting class changes at that line.

Ask the highway authority for its current street lighting specification before the reserved matters or discharge of conditions submission. Authorities update approved equipment lists regularly, and designing to last year's list is a common cause of rejection.

Designing to BS 5489-1 on a residential estate

BS 5489-1 is the code of practice for the design of road lighting in the UK, and it works alongside BS EN 13201, which sets out the lighting classes and how performance is calculated. Residential streets normally fall into the P series classes intended for pedestrian areas, while distributor roads serving the estate may need an M or C class.

Selecting the class is a judgement based on traffic speed, pedestrian use, crime risk and the presence of conflict areas such as junctions and crossings. The highway authority will usually tell you which class it expects, and that instruction should be in writing before any calculation is run.

The design output the authority wants is normally the same set of items.

• A lighting layout plan showing column positions, heights, lantern types and circuit routes.
• Isolux or grid calculations demonstrating the chosen class is met, including uniformity and, where relevant, semi-cylindrical illuminance.
• Equipment schedules taken from the authority's approved list, with LED colour temperature and output stated.
• The control arrangement, covering dimming profiles, part-night operation and any central management system the authority uses.
• Structural details for column foundations, including root and service constraints.

Colour temperature is worth settling early. Many authorities have moved to warmer LED sources for residential streets, partly for the reasons in the next section, and a design based on a cooler source may have to be redone.

Obtrusive light and the ecological constraint

Obtrusive light is assessed against the Institution of Lighting Professionals guidance on reducing obtrusive light, which sets environmental zones from intrinsically dark areas through to areas of high district brightness. Each zone carries limits on light trespass into windows, luminaire intensity and upward light.

Sites on the edge of a settlement, next to a National Landscape or adjoining open countryside frequently sit in a darker zone than the developer assumed. Establish the zone before designing, because it constrains column height, lantern optics and sometimes the road layout itself.

Bats are the other constraint, and on many sites they are the harder one. Lighting along hedgerows, watercourses and woodland edges can sever commuting routes, and the joint guidance from the Institution of Lighting Professionals and the Bat Conservation Trust sets out how to keep dark corridors. The practical measures are familiar: keep columns away from the feature, use directional optics with no upward spill, lower mounting heights near the corridor, and use warmer colour temperatures.

Where bats are present, the lighting design has to be agreed with the ecologist rather than handed to them for comment. A Preliminary Ecological Appraisal should identify commuting corridors early enough for the road layout to respond, and the resulting lighting scheme normally sits in a Lighting Assessment submitted with or after the application.

Where the columns can actually go

Column positions are constrained by more things than a lighting calculation suggests, and this is where designs unravel at technical approval.

Coordinate the lighting layout with the drainage, tree and service layouts on a single composite plan. Doing it sequentially produces a design where three disciplines have each claimed the same verge.

Highway objections tend to focus on visibility and access rather than on lighting itself, and what inspectors accept on highway objections at appeal is a useful guide to how much weight these points carry. Where the scheme affects a footpath or bridleway, the position of columns interacts with the diversion process covered under public rights of way affected by development.

Commuted sums and the section 38 agreement

A commuted sum is a capital payment to the highway authority to cover future maintenance of an asset it would not otherwise have taken on, or of equipment that costs more to maintain than the authority's standard.

Authorities differ in how they calculate it. Some charge a sum per column covering a stated design life. Some charge only for non-standard equipment such as heritage columns, bollard lighting or illuminated features. Some charge nothing for standard columns on an adopted road. Ask for the published basis rather than accepting a figure.

Three points that reduce exposure. Use equipment from the approved list wherever possible, because non-standard equipment is where the charges sit. Avoid lighting features that are decorative rather than functional, since those attract the highest sums. And resolve the adoption boundary early, because columns on the private side carry no commuted sum but do carry an estate charge that has to be disclosed to purchasers.

The agreement itself will also set a bond, a defects period and a technical approval process. Build the technical approval timescale into the programme. It routinely takes longer than applicants expect.

Private lighting on unadopted roads

Where the road stays private, the design is not governed by the highway authority's specification, and there is a temptation to lower the standard. Resist it. Purchasers, insurers and the management company all expect a design to a recognised class, and a scheme with dark stretches becomes a service charge dispute within a few years.

Design to the same BS 5489-1 class the authority would have required, document it, and hand the calculations and equipment schedules to the management company with the maintenance plan. Include the replacement interval for lanterns and the arrangement for electricity supply, which on private streets is an unmetered supply connection that someone has to hold.

Section 219 of the Highways Act 1980, the advance payments code, can also apply where new buildings are erected on a private street, and the authority may require a deposit against future adoption works. Check the position with the authority rather than assuming a private street stays private indefinitely.

The condition and what to submit under it

A typical lighting condition requires details of external lighting, including luminaire specifications, mounting heights, illuminance contours and hours of operation, to be approved before occupation and then implemented and retained.

Submit a single package rather than drip-feeding it. The layout plan, the calculations against the stated class, the equipment schedules, the obtrusive light assessment against the relevant environmental zone, the ecological sign-off where bats are present, and the control and dimming regime. Where the scheme is phased, say which phase the submission covers and make sure the condition is worded by phase.

One honest caution. Lighting conditions are among the most frequently breached on housing sites, usually because the as-built equipment differs from the approved schedule after a value engineering exercise. If the specification changes, vary the condition before installation rather than explaining it afterwards.

Enter your postcode on PlanScope to see which reports a residential scheme on your site is likely to need.

This is general guidance, not legal advice. Check the position with your local highway authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.