Why Homeowners Are Installing Air Conditioning in Modern Extensions Across Hampshire, Berkshire and Surrey

Modern extensions often bring large areas of glazing, open-plan layouts and flat roofs. These spaces look impressive but regularly suffer from overheating during warmer months. In response, homeowners across Winchester, Reading and Guildford are choosing air conditioning to stay in control of their indoor environment.

This blog explains why air conditioning is becoming standard in high-spec extensions and what you should consider when integrating it into your project.

Why modern extensions overheat

Contemporary home extensions typically include:

• Large south-facing bi-fold doors
• Flat or low-pitched roofs with minimal overhang
• Floor-to-ceiling windows with slim aluminium frames
• Open-plan kitchen and dining layouts

These features allow natural light but also introduce significant solar gain and limit cross-ventilation. During summer, these rooms often become uncomfortably hot, especially in homes built to modern airtightness standards.

On a property in Farnham completed in June 2023, internal temperatures reached 30°C in the new kitchen-diner despite shading and window ventilation. After air conditioning was added, the room stayed consistently at 22°C.

Why homeowners are adding air conditioning

Homeowners are no longer seeing air conditioning as a luxury. Instead, it is viewed as:

• A solution to summer overheating
• A way to protect property value and comfort
• A key component in glazing-heavy architecture
• A quiet and discreet system for targeted cooling

In Basingstoke, a family added air conditioning to their rear extension to keep the kitchen usable during summer. The unit was installed above a tall cabinet with a concealed line to the outdoor condenser.

Real project examples

Reading semi-detached home (Completed July 2023)

A flat-roof rear extension featured large windows and a skylight. Cooling demand was high despite insulation and blinds. A compact wall-mounted air conditioning unit was installed, with the condenser positioned on a flat roof section. The system maintained indoor comfort without affecting the aesthetic.

Winchester renovation with loft conversion (Autumn 2023)

The homeowners opted for multi-split air conditioning covering the new loft and open-plan kitchen. The installation allowed separate control in each zone. The external units were concealed behind a side gate, and the whole project was completed in under three days.

Guildford garden room (Spring 2024)

A detached garden office used for work-from-home was overheating due to solar gain. A small unit provided cooling and dehumidification, significantly improving daytime comfort and concentration levels.

Homeowner feedback

“We didn’t think we’d need it, but after one summer we knew we had to act. It made a huge difference.”
Homeowner, Guildford (2024)

“The system is quiet and out of the way. We use it almost daily between June and September.”
Couple, Reading (2023)

Planning and design considerations

For successful integration:

• Speak to your AC installer before internal layouts are fixed
• Confirm where pipe runs and condensers will be located
• Choose a unit size based on glazing area and orientation
• Review noise levels and placement of indoor units
• Consider dual-function systems that also provide heating

In a project in Petersfield completed in May 2024, the AC installer coordinated with the electrician to ensure control cables and power supplies were concealed behind new plasterboard ceilings.

Legal and technical standards

Residential installations must meet:

• F-Gas regulations for refrigerant handling
• Building Regulations Part L for energy efficiency
• Acoustic and visual planning guidance for listed and conservation zones

Proper documentation and commissioning are essential for warranty and compliance.

Why ClimateWorks is trusted for residential AC installations

We support homeowners across Surrey, Berkshire and Hampshire by:

• Helping plan unit placement and aesthetics
• Installing quiet, energy-efficient systems with minimal disruption
• Offering split and multi-split systems for different room types
• Providing clear documentation and support after installation
• Ensuring full legal compliance with certified engineers

Our approach protects both comfort and property value.

About the author

Dr. Julian Carter
Thermal Systems Expert and Technical Advisor at ClimateWorks

Dr. Julian Carter is a highly experienced thermal systems expert with over 15 years in the field, holding a PhD in thermal systems. His career spans academic research, consulting and teaching, focusing on air conditioning and refrigeration systems. Dr. Carter bridges the gap between theoretical advancements and practical applications, providing expert insights to organisations like ClimateWorks, where his guidance informs decision-making and industry best practices. Notably, he has worked on international projects with organisations such as Daikin Industries, the International Institute of Refrigeration (IIR), and the United Nations Environment Programme (UNEP). Currently a lecturer at Edinburgh University, Dr. Carter combines his expertise with a passion for educating the next generation of engineers and advancing climate control technologies.

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