What cable should I use for garden lighting?

For mains voltage (230 V) garden lighting, SWA (Steel Wire Armoured) cable is the standard choice for buried outdoor circuits. The steel wire armouring provides mechanical protection against spade damage, and the cable can be buried directly in the ground at a minimum depth of 0.5 m (or 0.6 m under a road or driveway). Yellow warning tape or cable covers should be placed above the cable at approximately 0.15 m depth. Common sizes are 2.5 mm squared 3-core SWA for lighting circuits and 4 mm squared or 6 mm squared for longer runs or higher loads. For SELV (12 V or 24 V) garden lighting, standard outdoor-rated flexible cable can be used, but it should still be protected from mechanical damage and UV degradation. Some manufacturers supply purpose-made outdoor lighting cable rated for direct burial.

Can I use a plug-in RCD for garden lights?

A plug-in RCD (also called a socket outlet RCD or portable RCD) provides 30 mA protection at the socket outlet. While this offers some protection, it is not a substitute for the fixed RCD protection required by BS 7671 for outdoor circuits. Regulation 411.3.3 requires that socket outlets with a rated current not exceeding 32 A that may reasonably be expected to supply portable equipment for use outdoors must be protected by a 30 mA RCD. For a permanently wired garden lighting circuit, the RCD must be a fixed device at the consumer unit — either an RCBO protecting the individual circuit or an RCD protecting a group of circuits that includes the outdoor lighting. A plug-in RCD could provide additional protection on top of the fixed RCD, but it does not replace it. For temporary outdoor lighting powered from an indoor socket (e.g., festive lights), a plug-in RCD is better than nothing but does not meet the standard for a permanent installation.

What IP rating do I need for outdoor garden lights?

The minimum IP rating depends on the installation location and exposure to weather. For wall-mounted lights under an eave or porch (sheltered from direct rain), IP44 is generally sufficient — this provides protection against solid objects greater than 1 mm and water splashing from any direction. For fully exposed wall-mounted or post-mounted lights, IP65 (dust-tight, protected against low-pressure water jets) or IP66 (dust-tight, protected against powerful water jets) is recommended. For ground-recessed or drive-over lights, IP67 (dust-tight, protected against temporary immersion) or IP68 (dust-tight, protected against continuous immersion) is required because these fittings are regularly submerged in rainwater. Always check the manufacturer declared IP rating and ensure it matches the installation conditions. A light rated IP44 installed in a fully exposed position would not meet the requirements.

Is SELV garden lighting safer than mains voltage?

SELV (Separated Extra-Low Voltage) garden lighting operates at 12 V or 24 V, which is below the threshold that can cause a lethal electric shock under most conditions. This makes SELV inherently safer than 230 V mains in terms of shock risk. However, SELV is not without its own challenges. The transformer must be correctly rated for the total lamp load (including inrush current for LED drivers), and the low voltage means higher currents and greater voltage drop over long cable runs. A 12 V system running 100 W of lighting draws 8.3 A compared with 0.43 A at 230 V — this means larger cable sizes are needed for the same run length. SELV transformers must comply with BS EN 61558-2-6 for safety isolation, and the transformer location must be dry, ventilated, and accessible. The mains supply to the transformer must still be RCD-protected. In summary: SELV reduces shock risk but requires careful design for voltage drop and load capacity. Mains voltage (230 V) is fine for outdoor use provided the circuit is RCD-protected, cables are correctly installed, and equipment has appropriate IP ratings.

How deep should garden lighting cables be buried?

Under BS 7671, buried cables must be installed at sufficient depth to avoid damage from foreseeable activities. For SWA cable in a domestic garden, the standard recommendation is a minimum burial depth of 0.5 m (500 mm) below finished ground level. Under driveways, paths, or other areas subject to vehicular traffic, a minimum of 0.6 m is recommended. The cable should be laid on a bed of fine sand or sifted soil, covered with a further layer of fine sand or sifted soil, and then a yellow warning tape or cable cover should be placed approximately 0.15 m (150 mm) above the cable before backfilling. Cable route markers should be placed at each end and at any change of direction. If using ducts or conduit, the same burial depths apply. The location of the cable route should be recorded on a plan and provided to the property owner as part of the installation documentation. This is particularly important because garden landscaping, fence post installation, and tree planting are common activities that can damage buried cables.

REGULATIONS GUIDE

Garden Lighting Regulations: The Complete Outdoor Electrical Guide

Outdoor lighting installations must meet BS 7671 requirements for IP ratings, cable protection, RCD protection, and Part P notification. This guide covers SWA cable burial depths, SELV options, mains voltage requirements, and common mistakes to avoid.

Start 7-day free trial

Free for 7 days · No charge until day 8 · Cancel anytime · Used by 1,000+ UK electricians

10 min readUpdated 2026-06-10Andrew Moore, Founder of Elec-Mate

Written and reviewed by Andrew Moore, founder of Elec-Mate, against BS 7671:2018+A4:2026, IET Guidance Note 3 and the IET On-Site Guide.

ShareX in W

1,000+

UK electricians

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”

Daniel Palmer — DP Electrical

Key Takeaways

1All outdoor lighting circuits must be protected by a 30 mA RCD under BS 7671 Regulation 411.3.3, regardless of whether the installation is mains voltage or extra-low voltage.
2SWA (Steel Wire Armoured) cable is the standard choice for buried outdoor circuits. It must be buried at a minimum depth of 0.5 m and protected by cable route markers or yellow warning tape.
3IP ratings for outdoor luminaires must be at least IP44 (sheltered locations) or IP65/IP66 (exposed locations). Ground-level fittings (drive-over lights) typically need IP67 or IP68.
4SELV (12 V or 24 V) garden lighting systems avoid the need for deep cable burial and reduce shock risk, but the transformer must still be RCD-protected and correctly rated.
5Elec-Mate cable sizing calculator handles SWA cable sizing for long outdoor runs, and the AI regulations lookup answers any question about outdoor installation requirements.

01 · Regulations Guide

Garden Lighting Regulations: What You Need to Know

Garden lighting is one of the most common outdoor electrical installations in the UK. From simple post-top lanterns along a path to elaborate landscape lighting schemes with ground-recessed uplighters and underwater pond lights, the range of installations is broad — but the regulations are consistent.

The key regulatory framework is BS 7671:2018+A4:2026 (the IET Wiring Regulations, 18th Edition with Amendment 4), supplemented by Approved Document P of the Building Regulations for England and Wales. Between them, these documents cover cable selection, burial depths, IP ratings, RCD protection, SELV/PELV options, and notification requirements.

Whether you are a homeowner commissioning outdoor lighting or an electrician designing and installing it, this guide covers every regulation and practical consideration you need.

Free download

Get the BS 7671 A4:2026 Cheat Sheet — free

Every key change in the 2026 amendment on one page. AFDDs, TN-C-S protection, new schedule columns, model forms. Pinned on your van dash.

Every regulation change summarised
New model forms (EIC + MEIWC)
Free PDF — no subscription

02 · Regulations Guide

IP Ratings for Outdoor Luminaires

Every outdoor light fitting must have an IP (Ingress Protection) rating appropriate for its location. The IP rating is a two-digit code: the first digit indicates protection against solid objects (dust), and the second digit indicates protection against water.

IP44 — suitable for sheltered locations (under eaves, porches, covered pergolas). Protected against solid objects greater than 1 mm and water splashing from any direction.
IP65 — suitable for exposed wall-mounted and post-mounted lights. Dust-tight and protected against low-pressure water jets from any direction.
IP66 — suitable for fully exposed locations subject to driving rain or hose-down cleaning. Dust-tight and protected against powerful water jets.
IP67/IP68 — required for ground-recessed, drive-over, and underwater fittings. Dust-tight and protected against temporary (IP67) or continuous (IP68) immersion.

Always check the manufacturer's declared IP rating against the installation conditions. A fitting rated IP44 installed in a fully exposed location does not meet the requirements and would be recorded as a defect on an EICR inspection.

03 · Regulations Guide

Cable Types and Burial Depths

The choice of cable for outdoor garden lighting depends on the voltage (mains or SELV) and the installation method (buried, surface-mounted, or overhead).

SWA (Steel Wire Armoured) cable — the standard choice for buried mains voltage outdoor circuits. The steel wire armouring provides mechanical protection, and the cable can be buried directly in the ground. Common sizes: 1.5 mm squared 3-core for lighting, 2.5 mm squared 3-core for mixed lighting and socket outlets.
Minimum burial depth: 0.5 m for domestic gardens. 0.6 m under driveways, paths, or areas subject to vehicular traffic. The cable must be laid on a bed of fine sand and covered with yellow warning tape or cable covers at 0.15 m above the cable.
Cable route markers must be placed at each end of the buried section and at every change of direction. The route must be recorded on a plan provided to the property owner.
SELV cable — for 12 V or 24 V systems, purpose-made outdoor lighting cable or suitably rated flexible cable can be used. It does not need to be armoured but must be protected from mechanical damage and UV degradation. Burial depths for SELV cable are less prescriptive, but 0.3 m minimum is good practice.

For long SWA runs, voltage drop must be checked. BS 7671 allows a maximum voltage drop of 3% for lighting circuits (6.9 V on a 230 V supply). On a 50 m run of 1.5 mm squared SWA, voltage drop can become an issue — use the voltage drop calculator to verify compliance.

04 · Regulations Guide

RCD Protection Requirements

All outdoor circuits must be protected by a 30 mA RCD under BS 7671 Regulation 411.3.3. This applies to both mains voltage and SELV circuits (the mains supply to the SELV transformer must be RCD-protected).

Dedicated RCBO — the preferred approach is to protect the outdoor lighting circuit with its own RCBO at the consumer unit. This provides both overcurrent and RCD protection on a single device and prevents nuisance tripping from affecting other circuits.
30 mA trip current — the RCD must have a rated residual operating current not exceeding 30 mA. This provides additional protection against electric shock in the event of a fault between live conductors and earth.
Type A or Type AC — for standard lighting loads, a Type AC RCD is sufficient. If the circuit includes LED drivers with DC components, a Type A RCD may be more appropriate to detect smooth DC fault currents.

If the garden lighting circuit also serves outdoor socket outlets, those sockets must have additional protection — typically via a separate RCBO for the socket circuit, or at minimum via the shared 30 mA RCD. Best practice is to keep lighting and socket circuits separate.

05 · Regulations Guide

SELV and PELV Options for Garden Lighting

Many garden lighting installations use SELV (Separated Extra-Low Voltage) at 12 V or 24 V instead of mains voltage. This significantly reduces the risk of electric shock and simplifies the cable installation requirements.

SELV (12 V / 24 V)

SELV provides electrical separation from the mains via a safety isolating transformer (BS EN 61558-2-6). The secondary circuit is not connected to earth. At 12 V, even with wet skin, the current cannot reach dangerous levels. Advantages: reduced shock risk, simpler cable burial requirements, no need for armoured cable. Disadvantages: higher currents mean larger cable sizes for long runs, voltage drop is more significant, and the transformer adds cost and must be housed in a dry location.

PELV (12 V / 24 V)

PELV (Protective Extra-Low Voltage) is similar to SELV but the secondary circuit is connected to earth. This provides a defined earth reference, which can be useful for some lighting control systems. PELV is not permitted in swimming pool zones (only SELV is allowed there) but is acceptable for general garden lighting. The transformer must still be a safety isolating type. The mains supply must be RCD-protected.

For most domestic garden lighting, SELV at 12 V is the simpler and safer option. Mains voltage (230 V) with SWA cable and RCD protection is the standard choice for larger or more professional installations where longer cable runs and higher lamp wattages make SELV impractical.

Try Elec-Mate free for 7 days

16 certificate types, 70+ calculators, RAMS, quoting, invoicing, AI agents, and 46+ training courses — from £6.99/mo.

Start free trial

06 · Regulations Guide

Part P Notification: When Is Garden Lighting Notifiable?

Under Approved Document P of the Building Regulations (England and Wales), certain outdoor electrical work is notifiable to Building Control.

Notifiable: Adding a new circuit from the consumer unit to supply outdoor lighting. This includes installing a new RCBO and running SWA cable to the garden.
Notifiable: Adding a new outdoor socket outlet on a new circuit.
Generally not notifiable: Replacing an existing outdoor light fitting on an existing circuit (like-for-like replacement). Adding a light fitting to an existing outdoor circuit via a spur (no new circuit from the consumer unit).

If you are registered with a competent person scheme (NICEIC, NAPIT, ELECSA), you can self-certify the work. You complete the installation, test it, issue an Electrical Installation Certificate (EIC), and notify Building Control electronically through your scheme provider. The homeowner receives a Building Regulations compliance certificate without needing a Building Control inspection visit.

If you are not registered with a competent person scheme, you must notify the local authority Building Control department before starting the work. They will arrange an inspection (which will incur a fee) and issue a completion certificate if the work is satisfactory.

07 · Regulations Guide

Design Considerations for Garden Lighting

Good garden lighting design combines aesthetics with electrical compliance. Here are the key technical considerations:

Voltage drop on long runs. BS 7671 limits voltage drop to 3% for lighting circuits (6.9 V on a 230 V supply). On a 40 m run of 1.5 mm squared 3-core SWA carrying 6 A, the voltage drop is approximately 5.8 V — within limits. For longer runs or higher loads, upsize the cable. For 12 V SELV systems, voltage drop is much more significant — a 5% drop on 12 V is only 0.6 V, which can visibly dim LEDs at the end of the run.
Junction boxes and connections. All outdoor junction boxes must have an IP rating appropriate for the location — typically IP66 or IP68 for buried or ground-level connections. Gel-filled junction boxes are commonly used for direct-burial connections as they maintain the IP rating after cable entry.
Switching and controls. Outdoor lighting can be controlled by manual switches, photocells (dusk-to-dawn sensors), PIR motion sensors, timers, or smart home systems. The control device must be rated for the lamp type (LED drivers have different inrush characteristics from incandescent lamps).
If the garden includes a pond or water feature, Section 702 requirements may apply depending on the size and design. Purpose-made pond lights are typically SELV (12 V) and rated IPX8 for submersion.

08 · Regulations Guide

Common Mistakes to Avoid

Garden lighting installations are straightforward if the regulations are followed correctly. Here are the most common mistakes found during EICR inspections:

Insufficient burial depth. SWA cable buried at 200 mm instead of 500 mm. This is a C2 (Potentially Dangerous) defect — a garden fork or rotavator can easily reach 200 mm depth.
No RCD protection. Outdoor circuits connected to a non-RCD protected MCB at the consumer unit. This is a C2 defect under Regulation 411.3.3.
Wrong IP rating for the location. An IP44 wall light installed in a fully exposed position, or an IP44 bollard light where water pools around the base. The IP rating must match the actual conditions.
Non-armoured cable buried without protection. Twin and earth (6242Y) cable buried directly in the ground without mechanical protection. This cable has no armouring and is not rated for direct burial.
No cable route documentation. No plan provided to the homeowner showing where the buried cables are routed. Future landscaping work could damage the cable.

Every one of these mistakes would be picked up on a competent EICR inspection. If you are installing garden lighting, getting it right first time saves the cost and disruption of remedial work later.

09 · Regulations Guide

For Electricians: Garden Lighting Made Easier

Garden lighting is profitable work — customers want it, it is relatively quick to install, and it generates follow-on work (outdoor sockets, hot tub circuits, EV chargers). The key is getting the design right, sizing the cable correctly, and completing the certification efficiently.

Cable Sizing Calculator

Size the SWA cable for the outdoor run with the Elec-Mate cable sizing calculator. Enter the load, cable length, installation method, and ambient temperature. Get the correct cable size with voltage drop and thermal checks — on your phone, on site.

AI Regulations Lookup

Not sure about the IP rating for a specific location? Need to check the burial depth requirement? Ask Elec-Mate AI and get the exact regulation reference with practical guidance — in seconds.

EIC Certificate

Complete the Electrical Installation Certificate for the new outdoor circuit on your phone. AI board scanner reads the consumer unit, voice entry captures test results, and the finished certificate is sent to the customer as a professional PDF.

Design and certify garden lighting faster

Cable sizing, voltage drop checks, AI regulations lookup, and digital certificates — all on your phone. Join 1,000+ UK electricians using Elec-Mate.

Try it free for 7 days

Frequently Asked Questions About Garden Lighting Regulations

What electricians say

Verified reviews from the UK App Store.

One App for Everything!

Elec-Mate is my go to app for business and electrical work. It's feature rich without feeling cluttered. A true all in one app for quotes, certs, calculations, RAMS, EICRs, and more. I use it every day without fail, and it makes my workflow much smoother since I'm not jumping between apps anymore. The price-to-feature ratio is excellent. Any issues I've had, the developer responds within the hour and usually fixes them the same day. 100% recommend.

Fantastic app for electricians

I've used the app and the web based version for a while now and it's well worth the investment. If you're an apprentice or experienced Spark give it a go, you won't be disappointed.

Absolutely amazing

I've been using Elec-Mate for a while now, and honestly, it's one of the best apps I've ever downloaded. Every aspect of it feels thoughtfully designed, from the clean and intuitive interface to the powerful features that make everything so easy to manage. It's clear that a lot of care and attention went into building this app, and it shows in every detail.

Trusted by electricians across the UK

Real feedback from real sparks

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”

Daniel Palmer

Sole Trader · DP Electrical

“I've won two contracts this month because I could turn quotes around same-day with the AI cost engineer.”

Nathan Perry

Electrician · NP Electrical Services

“The study centre got me through my AM2. Mock exams and flashcards are brilliant.”

Jake Pizey

3rd Year Apprentice · Apprentice

7-Day Free Trial — Cancel Anytime, No Hassle

Size Outdoor Cables in Seconds

Elec-Mate cable sizing calculator handles SWA runs, voltage drop checks, and thermal verification — plus AI regulations lookup for any outdoor installation question. 7-day free trial.

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”

Daniel Palmer, DP Electrical

From £6.99/mo after trial — less than a coffee a week

or download the app

7 days free, then from £6.99/moCancel in one tap — no calls, no hassleiOS, Android & WebBS 7671 compliant

Garden Lighting Regulations: The Complete Outdoor Electrical Guide

Key Takeaways

Garden Lighting Regulations: What You Need to Know

Get the BS 7671 A4:2026 Cheat Sheet — free

IP Ratings for Outdoor Luminaires

Cable Types and Burial Depths

RCD Protection Requirements

SELV and PELV Options for Garden Lighting

SELV (12 V / 24 V)

PELV (12 V / 24 V)

Try Elec-Mate free for 7 days

Part P Notification: When Is Garden Lighting Notifiable?

Design Considerations for Garden Lighting

Common Mistakes to Avoid

For Electricians: Garden Lighting Made Easier

Cable Sizing Calculator

AI Regulations Lookup

EIC Certificate

Design and certify garden lighting faster

Frequently Asked Questions About Garden Lighting Regulations

Do I need to notify Building Control for garden lighting?

What cable should I use for garden lighting?

Can I use a plug-in RCD for garden lights?

What IP rating do I need for outdoor garden lights?

Is SELV garden lighting safer than mains voltage?

How deep should garden lighting cables be buried?

Continue reading

Special Locations Part 7 Guide

Swimming Pool Electrical Regulations

Cable Sizing Calculator

Building Regulations Electrical

Earthing Arrangements Explained

Consumer Unit Regulations

What electricians say

One App for Everything!

Fantastic app for electricians

Absolutely amazing

Trusted by electricians across the UK

Size Outdoor Cables in Seconds