Garage & Workshop Electrical Installation London — Sub-Main, Sockets, Lighting Fitted
Adding power to a garage, workshop, garden office or outbuilding? F & A Electrical fits full electrical installations for outbuildings across London — dedicated SWA sub-main from your house, mini consumer unit in the outbuilding, multiple sockets, LED lighting, EV charger ready. From £780 inc VAT for a basic garage with 2 sockets + 1 light, up to £4,500+ for full workshop with 3-phase. NICEIC certified, Part P notified, 6 years’ warranty. Call 07407 627542 or 07500 721453.
Garage / workshop pricing — London 2026
| Setup | Price (inc VAT) |
|---|---|
| Basic garage — 2 sockets + 1 LED light (short cable run from house) | £780–£1,100 |
| Single-vehicle garage — 4 sockets + 2 lights + isolator + sub-board | £1,200–£1,700 |
| Double garage — 6 sockets + 3 lights + sub-main + EV-charger ready | £1,600–£2,400 |
| Full workshop — 8-12 sockets, dedicated tool circuit, lighting, heating, sub-main | £2,200–£4,500 |
| Garden office cabin — sub-main + 4-6 sockets + lights + data + heater | £1,400–£2,800 |
| 3-phase workshop (CNC, welding, compressor) | £3,500–£8,500+ |
| EV charger added to garage install (Zappi/Ohme/Pod Point) | +£550–£900 |
| SWA sub-main only (per metre, trenching by you) | £25–£40 per metre |
All-in: SWA armoured cable from house consumer unit to outbuilding, mini consumer unit in the outbuilding (Hager or Schneider), all sockets + lights + isolators, NICEIC certification, Part P notification via NICEIC, full Electrical Installation Certificate (EIC), 6 years’ NICEIC installation warranty.
What we typically install in a garage or workshop
- SWA sub-main — 6mm² or 10mm² 3-core SWA cable from your house consumer unit (via a dedicated RCBO) to the outbuilding. Buried at 600mm in a sand bed with marker tape, or surface-clipped in conduit.
- Mini consumer unit in the outbuilding — small RCBO board (Hager VML series or Schneider Easy9), typically 4-6 ways, with main switch + RCBO per circuit
- Power sockets — IP54 metal-clad for workshops, IP44 for clean garages, dedicated circuits for tool stations
- Lighting — LED batten lights (5ft/6ft), high-bay LED for tall workshops, PIR-triggered exterior light
- Heating — electric heater dedicated circuit, often with thermostat + frost stat
- Door isolator — emergency stop near the entrance for safety
- Data — Cat6 cable alongside power (30mm separation) for garden offices
- EV charger pre-wiring — even if you don’t have an EV yet, run the cable now (cheaper than retrofit)
Common garage / workshop scenarios
- Detached single garage, “just need a couple of sockets” — small SWA, 2-way consumer unit, 2 sockets + 1 LED. ~£900
- Integral double garage with EV intent — bigger sub-main, EV-ready cable run, 4 sockets, 2 lights. ~£1,800 + EV charger separately
- Hobby woodworking workshop — dedicated dust-extractor circuit, multiple tool socket circuits, bright LED lighting, heating, isolator. ~£2,500
- Garden office for working from home — sub-main, sockets, lights, heater, smart switch, data run. ~£2,000
- Mechanic / motorcycle workshop — 3-phase supply for lifts and compressor, multiple welding outlets, oil-resistant cabling, heated floor circuit. £4,000-£8,000+
- Music studio / home recording — dedicated clean-power circuit, separated earth, lots of low-current sockets, lighting on dimmer. ~£2,200
What’s included in a standard garage / workshop install
- Site survey — measure cable route, confirm earthing system, check existing consumer unit capacity, identify wall penetrations
- Quote with fixed price for the agreed scope
- Trenching — by you (cost saving) or by us (+£25-£40/m). Cable buried at 600mm minimum, sand bed, marker tape.
- SWA cable installation — pulled in, terminated at house end (via gland) and outbuilding end
- House-end RCBO at consumer unit (40A or 50A typically)
- Outbuilding consumer unit — Hager VML or Schneider Easy9, surface-mounted, fully labelled
- First-fix wiring — sockets, lights, isolators all wired and tested
- Second-fix accessories — switch plates, socket faces, light fittings
- Test — insulation resistance, polarity, Zs, RCD trip time, continuity
- Issue EIC + Part P notification via NICEIC. Building Control notified automatically.
- 6 years’ NICEIC installation warranty
EV charger ready — pre-wire while we’re there
If you’re getting electrical work done in the garage, run the EV charger cable NOW even if you don’t have an EV yet. Adding 10mm² SWA + Type B RCD ready for a Zappi/Ohme/Pod Point install later costs maybe £200-£400 extra. Retrofitting it later costs £550-£900. The economics are obvious.
For full EV charger install detail see our EV Charger Installation + EV Charger Cost London pages.
Common upgrade scenarios — what bumps the price
| Scenario | Cost on top (inc VAT) |
|---|---|
| House consumer unit can’t accept new sub-main RCBO | +£550-£950 (board upgrade) |
| Long cable run (over 25m) | +£25-£40 per extra metre |
| 3-phase supply where domestic is single-phase | +£800-£2,500+ (DNO involvement) |
| Underground rock / hard pan in trench route | POA — trenching surcharge |
| EV charger added during install | +£550-£900 |
| Smart lighting / heating control | +£280-£550 |
FAQ — garage & workshop electrical London
Can I do the trenching myself?
Yes — most customers do. We tell you exactly where to dig (600mm deep, 300mm wide), and we lay the cable + sand + marker tape when we’re on site. Saves £500-£1,500.
Do I need Building Regs approval?
For domestic outbuildings the Part P notification we file via NICEIC covers Building Control. No separate approval needed for most residential garages/workshops/cabins.
How long does the install take?
Half a day for basic 2-socket setup. 1 day for typical garage with sub-main. 2-3 days for full workshop or garden office.
Can you do consumer unit upgrade at the same time?
Yes — combining the house consumer unit upgrade with the new sub-main is much cheaper than two separate visits. £550-£950 extra for the board upgrade.
What if my outbuilding has its own water/gas supply?
We bond all incoming services to the local outbuilding earth and confirm equipotential bonding to BS 7671 spec.
Are you NICEIC certified?
Yes — NICEIC Approved Contractor, £5m public liability, Part P registered. Every install gets a sequential NICEIC certificate verifiable online.
Book your garage / workshop installation
Call 07407 627542 or 07500 721453, or email info@faelectrical.co.uk. Send us:
- Photo of your consumer unit
- Photo of the outbuilding (inside + outside)
- Distance from house to outbuilding
- What you want to power (just sockets + light, full workshop, garden office, EV charger, etc.)
Fixed-price quote within the hour. Booking within 1-2 weeks for larger installs.
Related: EV Charger Installation · Outdoor Sockets London · Three-Phase Electrician (Commercial) · Fuse Board Replacement Cost · All London service areas
Related: does an EICR cover the garage, shed or garden office?
Need the inspection rather than the installation? See EICRs for railway arches and industrial units.