How Much Does It Cost to Install Air Conditioning in a Flat?

With warmer summers becoming the norm in the UK, more people living in flats are looking into air conditioning as a long-term solution. But cost is often the first question. How much should you expect to pay for installation in a flat, and what factors influence the price?

The answer depends on the size of your flat, the type of system, and the permissions required.

Why Costs Differ in Flats Compared with Houses

Installing air conditioning in a flat often requires more planning than in a detached home. There are leasehold restrictions, freeholder approvals, and sometimes planning permission requirements. These extra steps can add cost, but they also ensure compliance.

The type of system you choose also has a big impact. A single split system will be far cheaper than a multi split system covering three or four rooms.

Typical Costs by System

• Single split system: £1,500 to £2,500 installed. This is ideal for a bedroom or living area.
• Multi split system (2–3 rooms): £3,000 to £5,000 installed. Common in larger flats where more than one room needs cooling.
• Full system across the flat: £6,000 upwards, depending on size and complexity.

These figures include supply and installation. Additional costs may apply for planning applications, freeholder approval, or specialist works such as running pipework through shared walls.

Running Costs After Installation

Beyond installation, many homeowners want to know how much air conditioning will cost to run. Based on Ofgem’s 2025 average electricity price of 28p per kWh:

• A 2.5kW bedroom unit costs around 20p per hour.
• A 5kW living room unit costs around 40p per hour.
• A multi split running two rooms for three hours may cost £1 to £1.50.

These figures show that air conditioning is affordable to run, especially compared with other appliances such as tumble dryers or electric ovens.

Examples from Local Installations

• In Reading, a two-bed leasehold flat had a single split system fitted in the lounge for £2,100, including installation.
• In Guildford, a three-room flat required a multi split system at a cost of £4,300, including permissions and freeholder consent.
• In Oxford, a high-spec installation in a city-centre flat reached £6,800 due to planning requirements in a conservation area.

Additional Factors That Influence Price

• Location of the outdoor condenser: Rooftop installations are more complex and costly.
• Leasehold permissions: Some freeholders require surveys or admin fees.
• Building type: Older buildings in Winchester or Oxford may need bespoke solutions.
• System efficiency: Higher efficiency models may cost more upfront but save on running costs.

Why Installation Costs Are Worth It

Although the initial investment can feel significant, air conditioning brings long-term value:

• Year-round comfort with both cooling and heating modes.
• Improved property value, particularly in cities like Basingstoke and Wokingham where buyers increasingly ask about air conditioning.
• Better indoor air quality with filtration systems that reduce dust and pollen.
• Lower reliance on electric heaters in winter, thanks to efficient heat pump technology.

Key Steps Before Installation

1. Review your lease agreement for any restrictions.
2. Contact your freeholder or management company for approval.
3. Confirm with your local council whether planning permission is needed.
4. Obtain multiple quotes from professional installers.
5. Ensure the system is correctly sized and located to avoid future issues.

Professional Guidance

At ClimateWorks, we guide leaseholders in Hampshire, Surrey, Berkshire, and Oxfordshire through every step of the process. From permissions in Oxford flats to multi split installations in Guildford, we make sure systems are designed to meet both your comfort needs and all regulatory requirements.

References

• Ofgem – Energy Price Data
• UK Government Planning Portal
• Energy Saving Trust – Cooling and Heating Guidance

Author Bio

Dr Julian Carter is Technical and Compliance Director at ClimateWorks. With over 25 years of experience in air conditioning, ventilation, and refrigeration, he specialises in residential and commercial system design. Julian advises homeowners, developers, and leaseholders on planning, compliance, and efficiency. He is also a visiting professor at a leading UK university, where he teaches sustainable building services.

‍