Installing garden lighting costs €50 to €600, depending on the system and the scale of the project. A simple 12V cable system with 10 spotlights can be done for €80–€150 and is safe to install yourself. A fixed 230V system with in-ground spots requires an electrician for the connection to the consumer unit (€100–€200 extra), but gives a more professional result. In this article you’ll find an overview of the different systems, the costs, and a step-by-step guide for DIY installation.
Which system do you choose?
Option 1: 12V low-voltage (plug-in)
The safest and simplest system to install yourself. A transformer lowers the voltage from 230V to 12V. The cables and spotlights are completely safe to handle yourself — no risk of electric shock.
Advantages: safe, no electrical knowledge needed, easy to expand
Disadvantages: limited output per transformer (max. 50–150W), cables visible or shallowly buried
Costs: €80 – €300 for a complete starter kit
Best for: terrace lighting, path lighting, spots in borders
Option 2: Fixed 230V system
Fixed cables (NYM cable) in the ground, connected to a dedicated circuit in the consumer unit. Professional result, suitable for large gardens and high-wattage fittings.
Advantages: unlimited output, more fitting types possible (wall lights, atmospheric lighting), hidden installation
Disadvantages: requires an electrician for the connection to the consumer unit, more expensive to install
Costs: €200 – €800 (incl. electrician for connection)
Best for: permanent mood lighting, large gardens, lamp posts, wall lights
Option 3: Solar power
No cables, no electrician costs. Solar panels charge a battery that powers the LED lighting at night. Quality is improving all the time, and ideal for remote parts of the garden.
Advantages: no cables, no energy costs, can be placed anywhere
Disadvantages: dependent on sunlight, less bright than wired lighting, battery needs replacing after 3–5 years
Costs: €20 – €200 per light / set
Best for: path lights, individual mood lights, remote locations
Cost comparison: DIY vs. hiring out
| System | Materials | Installation | Total |
|---|---|---|---|
| **12V (DIY)** | €100 – €300 | €0 | €100 – €300 |
| **230V (DIY + electrician for connection)** | €150 – €400 | €100 – €200 | €250 – €600 |
| **230V fully contracted out** | €150 – €400 | €300 – €600 | €450 – €1,000 |
| **Solar** | €50 – €200 | €0 | €50 – €200 |
Materials for a 12V system (10 spots, terrace 50 m²)
| Material | Price (guide) |
|---|---|
| 12V transformer 50W (with timer) | €40 – €80 |
| 12V ground spotlights (10 pieces) | €60 – €150 |
| 12V cable (2-core, 2×6 m) | €20 – €40 |
| T-connectors | €15 – €25 |
| Ground stakes for spotlights | €10 – €20 |
| **Total** | **€145 – €315** |
Step-by-step guide: installing 12V garden lighting
Step 1: Plan the lighting layout
Draw a plan of your garden and decide:
- Where do you want light? (terrace, path, borders, trees)
- How many spotlights or fittings do you need?
- Where is your socket or where do you want to connect the transformer?
Tip: use the 1-to-3 rule. 1 spotlight per 3 m² of terrace gives a pleasant lighting effect without being too bright.
Step 2: Choose the type of lighting
| Application | Recommended type | Watt |
|---|---|---|
| Path lighting | Ground spot or path light | 1–3W |
| Mood lighting terrace | Upward-facing ground spot | 3–5W |
| Accent lighting tree / plant | Garden spot | 5–10W |
| Functional light at entrance | Wall light 230V | 5–15W |
Always choose LED — LED uses 80% less electricity than halogen bulbs and lasts 20–30 times longer.
Step 3: Calculate the total wattage
Add up the wattage of all the fittings. The total must not exceed the maximum load of the transformer.
Example: 10 spots at 3W = 30W. A 50W transformer is sufficient. Always buy a transformer with 20–30% more capacity than your calculated requirement — to allow for expansion later.
Step 4: Run the cable
For a 12V system, you can run the cable:
- Above ground along planters or walls (use cable clips)
- Shallowly buried (10–15 cm, sufficient for 12V)
For a 230V system: cable must be buried at least 60 cm deep inside a white conduit (PVC pipe). This is a legal requirement in the UK.
Before digging cable trenches, use a cable detector to avoid existing underground cables and pipes.
Step 5: Install the spotlights or fittings
Push the ground spotlights into position. Connect the cable to the T-connector on each spotlight. Check at each connection that the locking mechanism clicks properly — loose connections are the most common cause of faults.
Aiming: angle spotlights obliquely towards the target — a 30–45 degree angle gives the most attractive lighting effect on plants, trees, and walls.
Step 6: Connect the transformer
Mount the transformer in a dry, sheltered spot (garden shed, outbuilding, under a pergola). Connect the cables to the transformer and plug the transformer into an outdoor socket.
Setting the timer: set a timer so the lighting comes on and goes off automatically. Most common setting: on 30 minutes after sunset, off at midnight.
Step 7: Test and adjust
Switch the system on and check every fitting. Adjust the aim of the spotlights and check there are no loose connections or weak points in the cables.
Troubleshooting: a spotlight not working? Check the connection on the T-connector. Is the connector properly locked? Is the bulb still working? Usually simple to fix.
Rules and safety
230V outdoors: the rules that apply
- All 230V outdoor installations must be protected by a residual current device (RCD)
- Only use fittings rated IP44 or higher for outdoor use (splash-proof)
- Underground cable must be buried at least 60 cm deep in a PVC conduit
- The connection to the consumer unit must be carried out by or approved by a certified electrician
12V: you can do it yourself
12V low-voltage systems using a safety isolating transformer can be completely installed by yourself. No planning permission needed, no electrician required.
Common mistakes
- Choosing a transformer that’s too small. Always buy more capacity than your calculated consumption. An overloaded transformer fails quickly.
- Cables buried too shallow. For 230V, 60 cm is the minimum. Too shallow is dangerous during any future digging work.
- Not checking the IP rating. An indoor fitting used outdoors isn’t suited to moisture and will fail quickly.
- Aiming spots straight down. Always aim spots obliquely at the target, never straight down — that gives flat, unattractive light.
- Lighting everything at once. Too much light in the garden is counterproductive. Limit lighting to the spots you really want to highlight.
Frequently asked questions
Can I install garden lighting myself?
12V low-voltage systems can be completely installed by yourself. For 230V outdoor installations, the connection to the consumer unit must be carried out by a certified electrician. The rest — running cables, connecting fittings — you can do yourself.
How deep does a garden cable need to be buried?
230V cables must be buried at least 60 cm deep in a white PVC conduit. 12V cables can be shallower (10–15 cm), but deeper is safer during any digging work.
What’s the difference between IP44 and IP65?
IP44 is splash-proof — suitable for gardens in sheltered positions. IP65 is fully dust-proof and jet-proof — suitable for spots that are directly exposed to rain. For garden lighting use at least IP44, preferably IP65.
Which colour temperature is best for outdoors?
Warm white (2700–3000K) gives a cosy, warm atmosphere — ideal for terrace and garden. Neutral white (4000K) is more functional for entrances and paths. Cool white (6000K+) is too harsh for the garden and unsuitable for mood lighting.
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