Home Backup Generator Installation Costs in the UK

Here’s what happens: you see a 10kW backup generator for £3,500 online. Looks perfect. You buy it.

Then reality hits. Electrician quotes £1,800. Plumber wants £650 for gas connection. Planning permission costs another £206. Concrete base is £400. Transfer switch? £850 plus fitting.

Your £3,500 generator just became a £7,500+ project.

I’m not trying to put you off. Backup power is brilliant. But you need to know the full picture before you commit. Let me walk you through the actual costs involved in a proper UK home backup installation.

Equipment Costs: What You’re Really Paying For

Generator Unit Pricing by Capacity

Let’s start with the generator itself. Prices vary based on size, fuel type, and brand quality.

These are generator-only prices for quality units from established manufacturers.

Budget Chinese imports might be 30-40% cheaper. They’ll also need more maintenance and have questionable parts availability. Your call.

Our standby generator range covers most domestic requirements, with units from Pramac, CAT, and Cummins.

Transfer Switch Equipment

Your generator can’t just plug into the mains. You need a transfer switch that:

• Detects mains power failure
• Starts the generator automatically
• Switches the load over safely
• Monitors for mains restoration
• Transfers back and shuts down

Manual Transfer Switch: £200-£500 You physically flip switches to change from mains to generator. Cheap, reliable, but you need to be home.

Automatic Transfer Switch (ATS): £600-£2,500 Does everything automatically. Power cuts happen, generator fires up, you don’t even wake up. This is what most people actually want.

Quality matters here. A failed transfer switch during a power cut means no power despite having a working generator. Buy proper kit from Socomec, ABB, or similar. Our ATS guide covers the technical details.

Optional but Recommended Equipment

Load Management System: £400-£1,200 Prioritises critical circuits, preventing generator overload. Your boiler stays on; the hot tub can wait.

Remote Monitoring: £300-£800 Check generator status from your phone. Get alerts for faults. Worth it for peace of mind when you’re away.

Acoustic Enclosure: £800-£2,500 Reduces noise by 15-25 dB. Essential for residential areas unless you enjoy neighbour complaints.

Installation Labour Costs

This is where costs vary wildly depending on your location and site complexity.

Electrical Work

You need a qualified electrician, preferably one experienced with generator installations. Not all sparkies understand backup power systems.

Basic Installation (Straightforward Site): £1,200-£2,000

• Install transfer switch
• Connect generator
• Wire to consumer unit
• Commission and test

Complex Installation: £2,500-£4,500

• Multiple transfer switches
• Load management system
• Whole-house backup across multiple circuits
• Integration with existing consumer unit upgrades

London and Southeast? Add 20-30% to these figures. Rural Scotland or Wales? You might save 10-15%, but travel costs could eat that up.

Gas Connection (If Applicable)

For LPG or natural gas generators, you need a Gas Safe registered engineer.

LPG Tank Connection: £500-£900 Includes pipework from existing tank, regulator, and connection to generator. Assumes tank is reasonably close (under 10m).

Natural Gas Connection: £800-£1,500 More complex. Might need pressure tests, new meter, and Building Control notification.

Gas generators cost more upfront but save money long-term. Our diesel vs petrol cost comparison applies similarly to gas options.

Groundworks and Preparation

Generators need proper foundations. Stick them on soil and they’ll sink, vibrate excessively, and cause problems.

Concrete Base: £300-£600 Minimum 100mm thick concrete pad, 150mm larger than generator footprint all round. Most installers sub this out to groundworkers.

Anti-Vibration Mounting: £150-£300 Reduces noise transmission through ground. Your neighbours will thank you.

Drainage: £200-£500 Generators produce condensation. You need somewhere for it to go that isn’t flooding your garden.

Planning and Regulatory Costs

Planning Permission

Most domestic generators fall under permitted development. But there are rules:

You DON’T need planning permission if:

• Generator is at least 1m from any boundary
• It’s behind the principal elevation (not at the front)
• Volume is under 0.6m³ for flue structures

You DO need planning permission if:

• None of the above apply
• You’re in a conservation area
• Listed building
• Flat or maisonette

Planning Application Fee: £206 for householder applications (England, 2025 rates). Scotland and Wales differ slightly.

Allow 8 weeks for a decision. Sometimes longer if neighbours object.

Building Regulations

If your installation involves structural work, new electrical circuits, or gas connections, Building Control needs to know.

Building Control Fee: £300-£500 depending on local authority Often covered by using certified installers who self-certify under Competent Person schemes.

Hidden Costs People Forget

Fuel Storage

Diesel Tanks Bunded tank (500-1000L): £400-£900 Installation and connection: £300-£600

You’re legally required to have bunded (double-skinned) tanks for domestic diesel storage over 200L in most areas.

LPG Tanks Rental: £40-60/year, plus you pay for gas Purchase: £800-£2,000 one-off, then you own it

Ongoing Costs

These aren’t installation costs, but factor them into your decision:

Annual Servicing: £150-£350 Essential. Backup generators sit idle most of the time. They need regular servicing to ensure they’ll actually work when needed.

Exercise Running: £5-10/month in fuel Generators should run under load monthly to keep everything operational. Budget 30 minutes per month.

Insurance Addition: £50-£150/year Notify your home insurer. Premium might increase slightly.

Real-World Installation Examples

Let me show you what actual projects cost.

Example 1: Basic Semi-Detached House Backup

Property: 3-bed semi, South East England
Requirements: Power essential circuits (boiler, fridge, lights, sockets)
Generator: 8kW diesel standby unit

Breakdown:

• Generator unit: £4,200
• Automatic transfer switch: £850
• Electrical installation: £1,600
• Concrete base and mounting: £450
• Diesel tank and connection: £700
• Planning permission: £206
• Building Control: £350
• Total: £8,356

Example 2: Detached House, Full Backup

Property: 4-bed detached, Midlands
Requirements: Whole-house backup with load management
Generator: 15kW diesel with acoustic enclosure

Breakdown:

• Generator unit with enclosure: £8,900
• Load management ATS: £1,800
• Electrical installation (complex): £3,200
• Gas connection to existing LPG: £850
• Groundworks and drainage: £800
• Remote monitoring system: £550
• Planning permission: Not required
• Total: £16,100

Example 3: Rural Property, Basic Setup

Property: Remote cottage, Wales
Requirements: Essential circuits only, manual switch
Generator: 6kW diesel portable in weatherproof housing

Breakdown:

• Generator unit: £2,800
• Manual transfer switch: £350
• Electrical installation: £900
• Base and weatherproof housing: £600
• No planning required (over 1m from boundary)
• Total: £4,650

How to Reduce Costs (Without Compromising Safety)

1. Size Appropriately

Don’t over-spec. A 12kW generator when you need 8kW wastes £2,000-3,000 upfront plus higher ongoing costs.

Use our sizing guide to calculate your actual requirement.

2. Consider Partial Home Backup

Do you really need every circuit backed up? Or just essentials?

Essential circuits only:

• Boiler
• Fridge/freezer
• Core lighting
• One socket ring

That’s a 5-7kW generator instead of 15kW. Save £4,000-6,000 on equipment alone.

3. DIY What You Legally Can

You CAN DIY:

• Concrete base (if capable)
• Diesel tank installation (non-pressurised systems)
• Weatherproof housing construction

You CANNOT DIY:

• Electrical connections (not certified)
• Gas connections (illegal without Gas Safe)
• Anything requiring Building Control sign-off

4. Timing and Negotiation

Get multiple quotes. Three minimum. Watch for:

• Itemised breakdown (so you can compare fairly)
• Call-out charges (some quoted separately)
• VAT (should be included in residential quotes)

Winter is quieter for installers. You might negotiate 10-15% off between November and February.

Financing Options

£8,000-15,000 is a lot of cash upfront. Options include:

Personal Loan: 5-8% APR typical for good credit Secured Loan: 3-6% APR, but your home is security Spread Payments: Some installers offer 0% finance over 12-24 months

Calculate total cost including interest. That 0% finance might have hidden charges or require insurance products.

Is It Worth the Investment?

That depends on:

How Often Do You Lose Power? If it’s twice a year for 30 minutes, probably not. If it’s monthly for hours, maybe yes.

What’s at Stake?

• Food spoilage in large freezers
• Home office income loss
• Medical equipment dependence
• Property damage from frozen pipes

Work out your actual cost of power cuts. If it’s £500+ per year, backup power pays for itself in 10-20 years. Plus, comfort and security have value too.

Choosing Quality Over Price

I’ve seen people try to save money with cheap generators and dodgy installers. It always costs more in the end.

Stick with established brands like Honda, Yamaha, FG Wilson, SDMO, or Perkins. Browse our complete generator brands for comparison.

Use certified installers. Check credentials. Get references.

A proper installation costs £7,000-15,000 for most homes. Budget accordingly. Factor in all costs from day one.

Then when the lights go out, you’ll be the house still running.