Outside Tap Installation in London -- Costs, Regulations and What to Expect
A standard outside tap installation takes 2-3 hours and costs £150-£300 fitted. Here's everything you need to know before booking.
2026 Pricing
Outside Tap Installation Costs in London
All prices below are fitted -- parts and labour included. Fixed quote given before work starts, no call-out fee on jobs over 2 hours.
Basic outside tap installation
£150-£250
Single tap, close to existing cold supply. Includes tap body, backplate and connection to cold water pipe.
Double check valve + non-return
£180-£300
Includes WRAS-compliant backflow protection -- required under UK water regulations. This is what every correctly installed outside tap should have.
Outside tap + isolation valve
£200-£350
Adds a dedicated indoor shut-off valve so you can isolate the outside tap in winter without turning off the kitchen cold supply.
What You Get
What's Included in an Outside Tap Installation
Included as standard
Not included (quoted separately)
Before You Book
What to Consider Before Booking
Location -- choose the shortest pipe run
Pick a spot close to the kitchen cold supply or a garden-side utility room. Every extra metre of pipe adds cost and increases the chance of a slow drip developing over time.
Brick vs render finish
Drilling through brick is straightforward. Drilling through rendered walls may leave a visible mark around the hole -- budget £50-£150 for render patching if appearance matters.
Always request an indoor isolation valve
Even if it adds £30-£50 to the job. Without one, a frozen tap in January means turning off the kitchen cold supply or calling a plumber in an emergency.
Hose reel at the same visit
A surface-mounted or wall hose reel can be fitted in the same visit for £30-£80 labour. Doing it now avoids a second call-out fee later.
Legal Requirements
UK Water Regulations -- What You Need to Know
Why outside taps need a double check valve
A garden hose left in a pond, a bucket of fertiliser, or a paddling pool can back-siphon contaminated water into the mains supply if mains pressure drops -- for example during a burst main nearby. Outside taps are classified as a Fluid Category 3 risk under the Water Supply (Water Fittings) Regulations 1999. This makes backflow protection a legal requirement, not an optional extra.
You DO need
You do NOT need
The Process
How an Outside Tap is Installed -- 5 Steps
Identify nearest cold water supply pipe
Usually under the kitchen sink or in a utility room on the garden-facing side of the property. The closer the supply pipe, the shorter the pipe run and the lower the cost.
Drill through the external wall
A core drill creates a clean hole through brick or blockwork. The plumber will check for electrics, the damp proof course (DPC), and structural elements before drilling. Render can be patched after -- this is quoted separately.
Tap into the supply pipe using a T-fitting
A T-junction or push-fit adapter is inserted into the cold water pipe inside the property. This is where the new branch to the outside tap originates.
Install isolation valve inside, route pipe through wall
An indoor isolation valve (quarter-turn stop valve) is fitted immediately after the T-junction. This lets you shut off the outside tap supply in winter without affecting the rest of the house. The new pipe then runs through the wall.
Fit tap body, backplate and double check valve; test
The tap body is mounted on a backplate screwed into the external wall. A double check valve is fitted on the outdoor side -- this is the WRAS-required backflow protection. The whole installation is tested under mains pressure and checked for leaks at every joint.
DIY vs Professional
Can You Install an Outside Tap Yourself?
Plumbing connections for outside taps are legal DIY in the UK -- unlike gas work, no Gas Safe registration or certification is required for a cold water connection. In practice, however, there are three meaningful risks:
Water regulations non-compliance
Getting the double check valve orientation wrong, or omitting it entirely, is a Water Supply Regulations breach. Water companies can disconnect your supply for non-compliance.
Wall drilling hazards
Drilling through external walls without a cable detector can hit electrics. Hitting the damp proof course (DPC) creates a moisture path into the wall. Misidentifying structural elements is rare but serious.
Hidden slow leaks
Push-fit connections made without proper pipe preparation (deburring, correct insertion depth) can drip slowly inside a wall cavity for months before becoming visible.
Recommendation
Handle the tap choice yourself -- brands like Hozelock and Pegler make good WRAS-approved taps at £25-£60. Book a plumber for the wall drilling and water connection. At £150-£250 fitted including parts, the labour cost is modest against the risk of a non-compliant installation or a slow internal leak.
Full Price Guide
Outside Tap Cost Table -- London 2026
| Job | Cost | Duration |
|---|---|---|
| Standard outside tap installation | £150-£250 | 2-3 hrs |
| With isolation valve + double check valve | £180-£300 | 2-3 hrs |
| Long pipe run (5-10m) | Add £50-£150 | +1 hr |
| Two outside taps (front + back) | £250-£450 | 3-5 hrs |
| Wall patching / render after drilling | £50-£150 | +1 hr |
| Hose reel fitting (at same visit) | £30-£80 | +30 min |
All prices include VAT. Fixed quote before work starts. No call-out fee on jobs over 2 hours.
Winter Maintenance
Protecting Your Outside Tap in Winter
Late October
Turn the indoor isolation valve to the off position. This cuts water to the outside tap without affecting the rest of the house.
Drain the pipe
After isolating, open the outside tap fully and leave it open for a few minutes to drain any water remaining in the pipe between the valve and the tap.
If it freezes anyway
Do not use a blowtorch or boiling water. Apply a warm damp cloth or a heat pad to the tap body. Boiling water can crack brass fittings.
April -- re-open
When frost risk has passed, close the outside tap, then slowly open the isolation valve inside. Check the tap and all joints for drips before leaving.
Common Questions
Frequently Asked Questions
Get Your Outside Tap Installed This Week
Fixed price, WRAS-compliant installation. Double check valve and indoor isolation valve fitted as standard.
Most installations completed in 2-3 hours. Call to book -- we cover all London boroughs.
No call-out fee on jobs over 2 hours · WRAS-compliant installation · All London boroughs