Summary

Water meter installation has two distinct customer journeys. The first is the free-of-charge meter installed by the water undertaker under the customer's right to be metered (or the undertaker's metering programme) — the plumber rarely sees this work. The second is private plumber work: bypass installations for testing or maintenance; sub-meters for HMOs and shared houses; meter relocations from outside chambers to inside utility rooms; and combined meter-and-stopcock packages where a property has neither.

Sub-metering in HMOs is the growing market. New legislation and increasing landlord interest in fair billing means private sub-meters fitted within a property to split water usage between tenants are a regular plumber job. These installations are NOT regulated by the water undertaker (they remain "private" meters for the landlord's own billing) but must still comply with the Water Regulations on backflow and material.

This guide covers pricing bands by scope, the customer-vs-undertaker decision, materials, fitting locations, the regulatory framework, and worked examples for the three most common UK installations. For broader plumbing scope see stopcocks and isolation valves.

Key Facts

Quick Reference Table

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Scenario Time Labour Materials Full Price
Meter swap on existing rising main 1.5–2 hr £180–£300 £40–£100 £220–£400
First meter install, inside property, existing rising main 2–3 hr £220–£380 £60–£150 £280–£530
First meter + bypass + isolation valves 2.5–4 hr £280–£480 £80–£180 £360–£660
Meter relocation (external chamber → internal) 4–6 hr £350–£600 £120–£220 £470–£820
HMO sub-meter (per branch) 1.5–2 hr each £180–£320 each £60–£140 each £240–£460 each
External meter in chamber + footway dig + reinstatement 6–8 hr £550–£950 £250–£400 £800–£1,350+
Combined meter + new stopcock + isolation upgrade 3–4 hr £320–£500 £100–£200 £420–£700

Detailed Guidance

Customer-Funded vs Undertaker-Funded

Most UK householders can have a free water meter installed by their undertaker. The plumber's paid work begins where:

Always clarify on first contact: "Have you spoken to your water company about a free meter? If not, that's typically the first step." Don't take work the customer can have for free — they'll be unhappy when they find out.

The Standard Internal Installation

A typical domestic meter install on an internal rising main:

  1. Locate rising main and stop-tap (usually under kitchen sink or in utility/airing cupboard)
  2. Notify customer of water-off period (typically 1–2 hours)
  3. Close the property stop-tap and main stopcock at the boundary if accessible
  4. Drain pipework above the cut point
  5. Cut rising main, fit:
    • 15mm full bore ball valve (upstream isolation)
    • WRAS-approved meter with strainer
    • 15mm full bore ball valve (downstream isolation)
    • Double check-valve if the property has appliances/conditions requiring it
  6. Re-pressurise and check for leaks
  7. Flush meter with at least one full property water turnover to clear pipe-jointing flux/sealant
  8. Record meter reading and label upstream/downstream valves

The whole sequence runs 2–3 hours including the legal pipework practices (no leaded solder on potable, WRAS-approved jointing compounds only).

Sub-Metering in HMOs

Sub-meters in HMOs need careful placement and labelling:

Tenancy agreements must allow sub-metering for billing. The Tenant Fees Act 2019 affects how water can be charged in residential tenancies — landlords should consult a property lawyer before installing.

The Bypass Arrangement

A bypass is a parallel pipe with full-bore ball valves that allows the meter to be isolated and removed without losing water service. Standard layout:

                        Meter
            Upstream ───[──M──]─── Downstream
            ball valve              ball valve

            Upstream ───[bypass valve]─── Downstream
                       (parallel run)

In normal operation: upstream and downstream meter valves open, bypass valve closed — water flows through the meter.

For testing: upstream meter valve open, bypass valve open — water flows through both (meter still records flow it sees).

For meter removal: close upstream and downstream meter valves, open bypass valve — water flows through bypass only.

Bypass is standard on commercial installations and sub-metering. On domestic single-meter work it's overspec unless customer specifically asks.

External Chamber Work

External meter chambers are required where:

The scope includes:

Total: half-day to full day depending on dig depth and reinstatement scope. £550–£950 labour + £250–£400 materials + £100–£200 licence.

Customer Pricing Conversations

A few common situations:

Common Site Overruns

Frequently Asked Questions

Does the customer save money on water bills with a meter?

For single people, small households, and customers with high rateable values relative to actual water use, yes — typical saving £150–£300 per year. For large families on low rateable values, switching to a meter may increase bills. Customers can check via their undertaker's online meter-or-not calculator. This is not the installer's advice to give in detail — refer them to the water company.

Who reads the sub-meter in an HMO?

The landlord. Sub-meters are private; the water undertaker reads only the main property meter. The landlord reads the sub-meters quarterly (or as set in the tenancy agreement), calculates each tenant's share, and bills them per the agreement. Sub-meters are not certified by Ofwat or the water undertaker.

Are smart meters available?

Yes — many undertakers fit smart meters (radio-read, automatic) as part of their metering programmes. Private smart sub-meters for HMO use are also available (£80–£200 per unit) with cellular or WiFi data feeds to a landlord dashboard.

Can a meter be fitted on a plastic (MDPE) rising main?

Yes — plastic-bodied or hybrid meters are available, with adapter fittings. Internal connections use compression or push-fit. WRAS approval applies regardless of pipe material.

Is there a minimum/maximum installation depth for an external meter?

External meters in chambers must be deep enough to avoid frost (typically 750mm minimum cover to top of pipework, per BS 8000-15:1990). Maximum depth is practical — the deeper the chamber, the harder it is to read. Typical chamber depth: 750–1,000mm.

Regulations & Standards