Hot Tub Installation Costs UK 2026 — Base, Electrics, Delivery and Running Costs

A Note on the Tub Itself

Before we get to the installation work, it helps to know roughly what your customer has already spent. Inflatable tubs (Lay-Z-Spa and similar) run £400–£900 and rarely need any of the work below. Entry-level rigid acrylic tubs start around £3,000–£5,000. Mid-range family tubs are £6,000–£10,000, and premium swim spas and large American imports run £12,000–£25,000+. The bigger and heavier the tub, the more serious the base and access requirements become — so the tub price is a useful early signal of how much installation work the job will carry.

The Base — The Single Most Important Element

A filled hot tub is heavy. A mid-size acrylic tub holds 1,000–1,500 litres of water, and once you add the shell, the cabinet and four to six adults, the total loaded weight is commonly 1,500–2,500kg concentrated on a footprint of around 4–6m². That load has to sit on something flat, level and structurally capable of carrying it for years without settling, cracking or tilting. A tub installed on an inadequate base will twist its frame, stress the acrylic shell and can void the manufacturer's warranty.

Level is non-negotiable. Most manufacturers specify a maximum fall of just a few millimetres across the whole base. An out-of-level tub puts uneven stress on the shell and can stop the water level sitting correctly across the seats and jets. This is why the base is the element trades should never cut corners on — and where you add the most value over a customer trying to DIY it.

Reinforced Concrete Pad

A poured reinforced concrete pad is the gold-standard base and the one most installers recommend for any rigid acrylic tub. A typical specification is a 100–150mm slab on a compacted MOT Type 1 sub-base, with steel mesh reinforcement, laid to a slight fall away from the tub for drainage. It will outlast the tub and never move.

• Small tub pad (up to ~6m²): £600–£1,200
• Larger tub or swim spa pad: £1,200–£2,000

Price varies with excavation depth, spoil removal, access for a mixer or barrows, and whether reinforcement and a damp-proof membrane are included. Quote the pad as its own line — it's real groundwork, not an afterthought.

Paving Slabs on a Bed

Heavy-duty paving slabs (40mm+) laid on a full mortar bed over a compacted sub-base are a common and cost-effective alternative to a poured pad, suitable for most domestic tubs. The key is a continuous bed — slabs spot-bedded on five dabs will rock and crack under hot tub loads. Done properly this is a perfectly sound base and is often quicker than waiting for a concrete pour to cure.

• Slab base on prepared sub-base: £500–£1,200

Composite or Timber Decking Base

Where the customer wants the tub set into a deck, the structure underneath must be engineered for the load — not a standard deck frame. That means closely spaced joists, often doubled-up bearers, and concrete pad footings or a slab directly under the tub footprint to take the point load. The deck around it is cosmetic; the tub itself should bear on solid ground, not on the deck timbers.

• Reinforced deck base with footings: £1,500–£3,500+

This is where decking-and-tub combination jobs get expensive — and where you must be explicit that a normal deck will not safely carry a loaded tub.

Gravel Sub-Base

A compacted gravel sub-base — well-graded aggregate over a geotextile membrane, properly consolidated and levelled — is the budget option and is acceptable for lighter tubs where the manufacturer permits it. It drains well, but it is more prone to settlement over time than concrete or bedded slabs, so set expectations about long-term level. Always check the tub manufacturer's base requirements before quoting gravel; many will not warrant a tub on aggregate alone.

• Compacted gravel sub-base: £300–£700

Electrical Installation — Notifiable Part P Work

This is the element where you absolutely cannot improvise. Inflatable tubs typically plug into a standard 13A socket via their own RCD lead, but most rigid acrylic tubs need a dedicated hard-wired supply — commonly a 32A circuit (sometimes 13A or 16A on smaller units), individually RCD-protected, run from the consumer unit in steel-wire armoured (SWA) cable to an outdoor-rated rotary isolator switch positioned within sight of, but not too close to, the tub.

Installing or extending a circuit to supply a hot tub is notifiable work under Part P of the Building Regulations. It must be carried out and certified by a registered competent-person electrician (NICEIC, NAPIT or equivalent), who issues an Electrical Installation Certificate and notifies Building Control. A tub fed by an uncertified DIY circuit is a genuine electrocution risk in a wet environment, and an uncertified install can invalidate insurance and warranties. If you are not the electrician, build the certified electrical connection into your quote as a sub-contracted line.

• Short cable run, simple connection: £350–£550
• Longer SWA run, new RCD/RCBO, trenching: £550–£900+
• Consumer unit upgrade if required: £400–£800 extra

The biggest cost driver is cable run length and whether the SWA has to be trenched across a garden, clipped along a wall or threaded through existing routes. Always confirm the consumer unit has a spare way and adequate capacity before pricing — an older board with no RCD protection or no free slots turns a simple connection into a board upgrade.

Delivery, Access and Craning

Getting the tub from the kerb to its base is its own line item, and access is the thing most likely to blow a quote apart. A dry tub is bulky — typically 2.0–2.4m square and 90cm+ tall — and weighs 250–450kg empty. Where there is clear, level side access of sufficient width, a team can wheel it in on a hot tub dolly for a modest delivery charge.

Where there is no side access — a terraced house, a tub destined for an enclosed back garden, or a route blocked by a conservatory — the tub has to be lifted over the house or fence by crane (HIAB or mobile crane). This is a significant cost and needs planning: the crane operator will assess reach, the lift radius, overhead cables and a safe set-down area.

• Standard delivery and positioning (good access): £100–£300
• Crane hire where no side access: £300–£800
• Long-reach or complex lift over a property: £800–£1,500+

Always survey access before quoting. Measure the narrowest pinch point — gate posts, side returns, steps — against the tub's footprint plus the dolly. If a crane is needed, get the crane firm to confirm price for the specific address; never absorb craning into a flat delivery figure.

Siting, Screening and the Surround

Most customers don't want a bare tub on a slab — they want a finished setting. Screening for privacy, a decking or paved surround, a step up to the tub rim, and sometimes a pergola or gazebo over it all add to the install. This is high-margin finishing work that turns a functional install into the photo-worthy result customers are really buying.

• Privacy screening / fence panels: £300–£900
• Decking or paved surround: £800–£3,000
• Pergola or gazebo over the tub: £1,000–£4,000+

Keep a service-access gap around the tub. The cabinet panels need to come off for pump and heater maintenance, so a surround built tight against the tub on all four sides creates problems later. Leave a removable section or a 60cm clear strip on the equipment side.

Planning and Decking Considerations

A hot tub itself doesn't usually need planning permission, but the structures around it can. Decking is normally permitted development provided it sits no more than 300mm above ground level and, with other extensions, covers no more than 50% of the garden — above that, or in some cases for raised decking overlooking a neighbour, planning permission may be required. A solid-roofed gazebo, a tall screen, or any structure in a conservation area or on a listed property needs checking with the local authority.

Flag this to the customer in writing. You don't want to build a raised deck and surround only for a neighbour complaint to bring the planning department to the door. A line in your quote noting that planning compliance for surrounding structures is the customer's responsibility, with a recommendation to confirm with their council, protects you.

Ongoing Running Costs

Customers always ask what a tub costs to run, and giving them a straight answer at quote stage builds trust. Running cost depends on tub insulation, how often it's used, the cover quality and the local climate, but realistic figures are:

• Electricity: £30–£100/month for a well-insulated tub kept warm year-round — more in winter and for poorly insulated or larger tubs.
• Chemicals: £15–£30/month for chlorine or bromine, test strips, pH balancers and filter cleaner.
• Filters: £20–£60 every few months depending on the tub.
• Water: a full drain-and-refill every 3–4 months, modest on most metered supplies.

A good insulated cover is the single biggest lever on running cost — it's worth recommending a quality replacement cover as part of the install if the customer's is thin.

Quoting Tips — What to Check Before You Price

Hot tub installs go wrong when the trade prices off a photo and a postcode rather than a site visit. Before you commit a number, confirm:

• Tub make, model and filled weight: This sets the base spec and whether a crane is likely. Get it from the customer's order confirmation.
• Ground conditions: Soft, sloping or made-up ground means deeper excavation and more sub-base. Check for drains, soakaways and tree roots in the footprint.
• Access route: Measure the narrowest pinch point against the dry tub footprint plus the dolly. Decide early if a crane is needed.
• Consumer unit: Spare ways, RCD protection and capacity. An old board changes the electrical price materially.
• Cable run: Distance from board to tub and whether SWA must be trenched, clipped or routed through the building.
• Surround scope: Pin down exactly what screening, decking or pergola the customer expects — this is where scope creep hides.

Break your quote into clear lines — base, electrics (sub-contracted and certified), delivery and craning, surround — so the customer sees where their money goes and you're not undercut by an operator who quietly omits proper groundwork or certified electrics.

Quick Reference: Hot Tub Installation Costs UK 2026