UK Air Conditioner Installation: Prices, Timing & Money-Saving Tips
If you’ve been thinking about installing an air conditioner to stay comfortable during the UK’s increasingly frequent heatwaves, one of the first things you’re probably wondering is: How much will it cost? The answer isn’t always straightforward—it depends on the type of system you choose, your home’s layout, and a few other key factors.
In this guide, you’ll find clear, practical information on air conditioner installation costs in the UK, how long it typically takes, and smart ways to save without cutting corners on comfort.
How Much Does Air Conditioner Installation Cost in UK Homes?
If you’re planning to install an air conditioner, the first thing you’ll want to know is the price. For most UK homes, a professionally installed wall-mounted split unit comes in between £1,800 and £3,000 for one room.
That includes both the indoor unit and the outdoor condenser, plus a standard one-day fit. Across the country, recent reports put the average fitted cost at around £2,850, which is very much in line with what installers are quoting right now.
While that’s a good starting point, the real cost depends on the type of system you choose, the size of the space you’re cooling, and how many rooms you want to cover. Let’s break down the most common options:
Single split (one room, e.g. bedroom or living room)
For most people, this is the go-to choice. A mid-range wall-mounted split AC installation will usually cost £1,900–£3,000+.
Typical size: 2.5–3.5 kW (about 9,000–12,000 BTU/hr), ideal for the average UK bedroom or lounge.
To give you a sense of the breakdown, a 12,000 BTU unit might be around £750 to buy, with installation coming in at roughly £1,150.
Multi-split (2–4 rooms on one outdoor unit)
If you want cooling in more than one space, a multi-split system can be more efficient than fitting several singles. These usually start at around £3,000 and can climb to £6,500+ depending on how many indoor units you add and how the pipework is routed.
Typical combined size: 5.0–7.0 kW (about 18,000–24,000 BTU/hr), which is enough to cool two or three average-sized rooms.
Ducted or “central” systems (discreet ceiling grilles)
For a more seamless look, ducted systems hide the units in your ceiling or loft space, with only vents visible. The trade-off is a higher price and more involved installation. Expect £5,500–£15,000+, driven largely by ductwork complexity and access.
Typical size: 5.0–12.5 kW (about 18,000–43,000 BTU/hr), making these suitable for large zones or entire floors.
Portable air conditioners
If you’re renting or on a tighter budget, a quiet portable air conditioner can give you seasonal cooling without the commitment of permanent installation. Prices range from £300–£700 for the unit itself, and there’s virtually no install cost beyond venting the hose.
Typical size: 6,000–12,000 BTU/hr (around 1.8–3.5 kW). A 6,000 BTU unit suits rooms of about 11–17 m², while 9,000 BTU models cover 22–26 m².
Here’s a quick overview of AC installation UK costs:
System type | Typical cooling size | Room coverage | Installed cost |
Single split (1 room) | 9,000–12,000 BTU | Most bedrooms/lounges (~20–30 m²) | £1,900–£3,000+ |
Multi-split (2–4 rooms) | 18,000–24,000 BTU | 2–3 average rooms | £3,000–£6,500+ |
Ducted/ “central” | 18,000–43,000 BTU | Large zones/floor | £5,500–£15,000+ |
Portable (no install) | 6,000–12,000 BTU | ~11–30 m² | £300–£700 (unit only) |
Factors Affecting Air Conditioning Installation Costs
There’s no one-size-fits-all price for air conditioning. Even if two homes order the same model, the final bill can vary because every property and every installation is different. Here are the main factors that shape the cost:
System type and size (kW/BTU)
The bigger the cooling demand, the bigger the unit and the bigger the price tag. Most UK rooms need 2.5–3.5 kW (around 9,000–12,000 BTU/hr), while larger, open-plan spaces might call for 5.0 kW (about 18,000 BTU) or more. Oversizing wastes energy; under sizing leaves you uncomfortably warm, so it’s worth getting a proper heat-load calculation rather than relying on guesswork.
If you’re wondering, “What size air conditioner do I need?” a common rule of thumb is roughly 340–440 BTU/hr per m² for typical UK rooms, adjusted for insulation, glazing, orientation and heat gains.
Number of rooms
A single split system cools just one space, but if you want more coverage, you’ll need a multi-split. That means one outdoor unit feeding two, three or even four indoor heads, and with every additional room, you’re adding equipment, pipework, and time on site.
Installation complexity
Not every job is as simple as drilling a hole and running a short pipe. Long refrigerant lines, drilling through thick stone or brick, or routing condensate drains neatly can all add hours. Outdoor units placed high on walls or rooftops will also take longer to fit.
Electrical work
Some installations can tap into existing wiring, but many need a dedicated fused spur and an external isolation switch. If your fuse board is full or far from where the outdoor unit will go, expect extra labour and materials.
Access and finishing
Limited parking, tight lofts, or awkward rear access can slow the team down. If you’d prefer cables and pipes hidden inside walls instead of surface-mounted trunking, factor in the extra building work and any redecorating afterwards.
Brand, efficiency, and add-ons
Premium brands, quieter fans, high-efficiency ratings, Wi-Fi controls, or specialist filters can push the supply cost up, though they often pay off in comfort, running costs, and warranty cover.
Location and timing
In London and the South East, higher labour rates mean higher quotes. The time of year matters too: during summer heatwaves, demand surges and so can prices, not to mention longer lead times.
Permissions and property type
If you’re in a flat, a listed building, or a rental, you may need formal permission for an outdoor unit. Noise limits, building rules, and even neighbour concerns can affect what’s possible and how much it costs.
How Long Does It Take to Install an Air Conditioner?
Most straightforward, single-room installations are done in a day, but more involved projects take longer. Here’s what the timeline and the process on how to install an air conditioner usually look like:
1. Survey and quote
It starts with a survey, either remote or on-site, to check room sizes, possible pipe routes, and where the outdoor unit could go. This takes around 30–60 minutes, and you’ll usually get a detailed, itemised quote within one to three working days.
2. Lead time before installation
In quieter months, you can often get booked in within one to two weeks of accepting a quote. In peak summer, especially during a heatwave, that can stretch longer, so planning ahead pays off.
3. Installation day(s)
Single split with back-to-back walls: The quickest option, taking 4–8 hours.
Single split with longer runs or tricky routing: Around 1–1.5 days, to allow for chasing walls, boxing-in pipes, or fitting condensate pumps.
Multi-split (2–4 indoor units): Usually 1–3 days, depending on how many rooms and how accessible they are.
Ducted or central systems: More complex jobs that can take 3–7+ days, as they involve running ductwork, working in ceilings, and often coordinating with builders.
4. Electrical work and compliance
If a new circuit is needed, a qualified electrician will need extra time to install and test it. Your installer should also be F-Gas certified and will carry out all the refrigerant handling, pressure testing, and vacuum work before the system is switched on.
5. Commissioning and handover
Once everything’s installed, expect another hour or two for final checks: leak testing, refrigerant charge verification, and setting up the controls. You’ll also get a walkthrough of how to use the system, warranty details, and advice on maintenance.
6. Making good
Most small holes are sealed on the day. If you’ve had walls chased or pipework concealed, you may need separate plastering and decorating after the installation team has finished.
Tips for Saving Costs on Air Conditioning Installation
Keeping your air conditioning costs under control is making smart choices from the start. The right planning, layout, and equipment can help you get the comfort you want without overspending.
Right-size the system (kW/BTU)
Start with the right capacity. Many UK rooms are well served by 9,000–12,000 BTU, while large or open-plan areas may need around 18,000 BTU. A proper heat-load calculation will ensure you’re not paying for unused capacity or struggling with an undersized unit.
Keep the layout simple
Whenever possible, go for a back-to-back install—placing the indoor unit on the other side of the wall from the outdoor unit. Shorter pipe runs and easier access means less labour and fewer materials.
Get like-for-like quotes
Aim for at least three detailed, itemised quotes. They should show unit size (in kW/BTU), brand, model, labour costs, electrical work, pipe lengths, access equipment, and any “making good” after the fit. This way, you’re comparing apples to apples.
Choose the right timing
Spring and autumn are often quieter for installers, so you might benefit from shorter lead times and, occasionally, better prices than peak summer.
Plan for future expansion
If you might add more rooms later, check whether your chosen outdoor unit can support additional indoor heads. It’s often cheaper to future-proof now than to replace equipment later.
Minimise access costs
Ground-level outdoor units are generally easier (and cheaper) to install than high-level mounts requiring scaffolding. If scaffolding is unavoidable, see if you can share the cost with neighbours or combine it with other building work.
Lower the cooling load
Simple measures like shading sunny windows, closing blinds in the afternoon, and improving draught-proofing can reduce your BTU needs—sometimes enough to drop down a unit size.
Check VAT rates and incentives
Standard air conditioning is typically VAT-rated at 20%, but some low-carbon systems qualify for reduced VAT or government schemes. Ask your installer what’s relevant for your property.
Go portable when it makes sense
If you’re in a rental, only cooling one room for short periods, or need something you can move around, investing in one of the best portable air conditioners can be a more budget-friendly option. There’s no fixed installation cost—just plug it in, vent the hose, and you’re ready. Portable units are a bit less efficient than fixed systems, but if you match the BTU to the room size, they can be a smart, flexible way to stay cool without a big investment.
When portability is a priority but you still want capable cooling (and even heating), the EcoFlow WAVE 3 Portable Air Conditioner is worth a look. It delivers 6,100 BTU cooling and 6,800 BTU heating, along with fast temperature changes and app control for easy adjustments.
With the optional 1,024Wh LFP add-on battery, it can run wire-free for up to eight hours, ideal for spots without mains access. Multiple charging options and a compact exhaust setup make it a flexible choice for effective cooling in home offices, rentals, or off-grid situations.
EcoFlow WAVE 3 Portable Air Conditioner
Conclusion
Air conditioner installation can be a smart investment for comfort and home value—provided you choose the right system, size, and installer. By understanding the factors that influence cost, knowing how long installation takes, and applying practical money-saving tips, you can keep cool without overspending. Whether you opt for a fixed split system or a portable unit for flexible use, planning ahead ensures you get the best balance of performance and budget.
FAQs
How much does it cost to get an aircon installed?
For a single room, a typical wall-mounted split system in the UK usually costs between £1,800 and £3,000 fully installed. As an example, a 12,000 BTU unit might be around £750, with installation adding another £1,150, plus £400–£700 if extra electrical work is needed.
Multi-room setups (multi-split systems) often range from £3,000 to £7,000+, depending on the property and pipe runs. Portable units are cheaper—typically £350–£700—though they can be noisier and less efficient. Recent figures put the UK average installation cost at about £2,850.
Do I need planning permission to install an air conditioning unit?
In most cases, you won’t need planning permission in England if your system is a reversible heat pump (as most modern AC units are) and meets Permitted Development rules. The outdoor unit must be no larger than 1.5 m³ for houses (0.6 m³ for flats), not placed on a pitched roof, at least 1 m from the edge of any flat roof, and it can’t be for cooling only.
There are extra restrictions for conservation areas, listed buildings, and World Heritage Sites. Flats also have stricter siting rules. Always check with your local planning office before going ahead.
Can I install air conditioning myself in the UK?
You can easily set up portable units yourself—just plug in, vent the hose, and you’re good to go—making them ideal for renters or temporary use. However, installing a fixed split system is different: if it contains F-gases, UK law requires installation by a qualified engineer working for a certified company.
Attempting this without the right credentials can lead to enforcement action. You can find approved installers through REFCOM. Any electrical work should also meet Part P of the Building Regulations. For a no-install, no-fuss solution, the EcoFlow WAVE 3 Portable Air Conditioner offers 6,100 BTU of efficient cooling and an optional battery for cordless operation.