Shower Installation London: Types, Costs and What to Expect

Check Your Water Pressure First

The most important factor in choosing a shower type for a London property is your water pressure — and specifically whether you have mains-fed pressure or gravity-fed low pressure. Before selecting a shower, measure or assess your pressure:

• Mains-fed properties: Most London properties built from the 1990s onward, and many older properties with a system upgrade, are supplied directly from the mains at the shower. Typical mains pressure in London is 1–3 bar, which is sufficient for most shower types.
• Gravity-fed properties: Older London properties — particularly Victorian terraces with a cold water storage tank in the loft — may have gravity pressure of only 0.1–0.5 bar at the shower, depending on the height difference between the tank and the shower head. This is inadequate for a standard mixer shower without a pump.

A quick test: fill a 1-litre container from the shower supply (cold only). If it fills in under 6 seconds (roughly 10 litres per minute), pressure is acceptable for a mixer shower. If it takes 10+ seconds, pressure is low and an electric shower or pump solution is required.

Electric Showers

An electric shower heats cold mains water on demand using an internal electric element — the same principle as a kettle. It connects only to the cold mains water supply and to an electrical circuit. It operates entirely independently of the boiler or any hot water system.

Electric showers are the most common shower type in London flats, for several reasons:

• They work on low mains pressure (most models require just 0.7 bar minimum)
• They work regardless of whether the boiler is functioning
• They provide instant hot water with no wait time
• They are economical — you only heat the water you use

The limitation is flow rate. Because the water is heated as it passes through a small element (typically 7.5–10.5 kW for domestic models), the flow rate at higher temperatures is modest — around 5–8 litres per minute compared to 10–15 litres per minute for a mixer shower at the same pressure. The higher the power (kW rating), the better the flow rate at a given temperature.

Electric shower installation requires a new dedicated electrical circuit from the consumer unit — a 6mm² cable on a 40-amp MCB for most domestic models. This is notifiable work under Part P of the Building Regulations and must be carried out by a qualified electrician. The plumbing connection (a 15mm cold mains supply) is straightforward for a plumber.

Installed cost in London: £350–£600 (including electrician for new circuit, plumber for water connection, shower unit, and accessories). Upgrading an existing electric shower where the circuit already exists: £200–£350.

Mixer Showers

A mixer shower combines hot and cold supplies (from the boiler and cold mains or storage tank) to deliver water at the user's chosen temperature. Manual mixer showers use a single control valve to mix temperature; thermostatic mixer showers maintain a set temperature regardless of pressure fluctuations and shut off if the cold supply fails (an important safety feature preventing scalding).

Thermostatic mixer showers are the preferred choice for properties with adequate pressure. They require:

• A minimum of 0.5 bar pressure (for some models) but ideally 1 bar or above for a satisfying flow rate
• Both a hot water supply (from the boiler) and a cold water supply at balanced pressures — pressure imbalance between hot and cold causes the thermostatic valve to compensate continuously, reducing performance

For London flats with gravity-fed supplies, a mixer shower requires a pump to function adequately — see Power Showers below.

Installed cost in London: £400–£700 (thermostatic valve, handset, riser rail, and plumbing). More complex tile-in fixed head installations cost £600–£1,000 or more with tiling.

Power Showers

A power shower is a mixer shower with an integral pump built into the unit. The pump boosts the hot and cold supplies entering the unit, providing high flow rates even on gravity-fed low-pressure systems. Power showers require:

• A hot water cylinder (not a combi boiler — combi boilers deliver hot water at mains pressure and cannot be combined with a pump)
• A cold water storage tank (gravity-fed supply) — they are specifically designed for this scenario
• A nearby electrical supply for the pump (the shower's electrical connection)

Power showers are not suitable for combi boiler systems — do not attempt to add a pump to a combi-fed mixer shower circuit. For combi boiler systems with low pressure, a whole-house inline pump or pressure-boosting unit is the correct approach.

Installed cost in London: £600–£900 (including unit, electrical connection, and plumbing).

Digital Showers

Digital showers use an electronic control valve (typically remote from the shower position, in an airing cupboard or under the floor) connected by cables to a digital controller at the shower. Benefits include precise temperature control, remote start from a smartphone app, and highly specified performance. Premium brands include Aqualisa, Mira, and Kohler.

Digital showers are not a different pressure solution — they can be supplied from mains, from a hot and cold balanced supply, or with a pump. The digital element is a control technology upgrade, not a pressure solution. Installed cost: £800–£2,500+ depending on specification.

Wet Rooms

A wet room is a fully waterproofed shower room with no shower tray — water drains through a floor-level drain. The installation challenge is waterproofing the floor and walls, typically using a tanking membrane system under tiles. For a London flat, a structural survey may be needed to confirm the floor can support the tanking, tiles, and water loading. Wet rooms are typically installed as part of a full bathroom renovation rather than as a standalone shower installation.

London Flat Considerations

Several factors specific to London flats apply when planning a shower installation:

• Building management sign-off: Leasehold flats typically require the freeholder or managing agent's consent for any works affecting the structure, plumbing, or electrical system. Check your lease before starting work.
• Extraction ventilation: Building regulations require adequate ventilation in shower rooms (minimum 15 litres per second for intermittent fans). If you are adding a shower to a room without existing ventilation, an extractor fan installation is part of the job — and the fan circuit must be notified under Part P.
• Waterproofing behind shower walls: In a flat, a water leak from a shower — particularly through a poorly tiled or unsealed shower enclosure — can cause significant damage to the property below. Always use a tanking membrane behind shower tiles, not just adhesive waterproofing properties of the tile grout.
• Hot water capacity: If the property has an unvented cylinder, confirm it is correctly sized for the added shower demand. Adding a high-flow thermostatic shower to a property with a small cylinder can result in rapid hot water depletion.