Air conditioning for new builds in Ireland: plan it before first fix
The short answer
Decide on cooling at design stage, and no later than first fix. Built-in pipework and planned unit positions cost less, look better, and perform better than any retrofit. Most self-builds land on a multi-split covering the vulnerable rooms (south-facing bedrooms, attic rooms, home office) at €4,500–€7,500. A build is also the only realistic moment to consider ducted.
A growing share of the enquiries through Aercon are people mid-build or about to break ground, and they're the smartest customers we see. They've stood in a friend's two-year-old A-rated house in July and decided not to repeat the experiment. If that's you, this guide covers what to decide, when to decide it, and what it costs.
Why new builds are the overheating risk, not the exception
Modern Irish building standards produce airtight, heavily insulated, generously glazed homes. Superb in January; a heat trap in July. Solar gain pours in through the big south and west glazing, internal gains from cooking and appliances add to it, and the insulation holds it all in. One in ten Irish homes is now considered at risk of overheating, and new builds lead the statistics. The full mechanics are in our guide to why A-rated homes overheat.
The rooms that suffer most are predictable at design stage: south and west-facing bedrooms, rooms under the roof, and home offices with equipment running. Which means the fix can be designed in too.
The timeline: what to decide when
Design stage
- Shading first. The cheapest cooling is heat that never enters. Roof overhangs, external blinds or shutters on south and west glazing, and glazing g-values are design decisions that cost little now and are expensive later.
- Decide which rooms get active cooling. Usually two to four: the main bedrooms, an attic room, the office. Whole-house cooling is rarely needed in Ireland.
- Choose multi-split or ducted. A build is the one time ducted is realistic, because ceiling voids can be sized for it. It's invisible and very quiet, but €10,000+. Most self-builds take the multi-split at €4,500 to €7,500 and spend the difference elsewhere.
Before first fix
- Get the AC installer on site with your electrician and plumber. Refrigerant pipe routes, condensate drains, and cabling get built into walls and floors, invisible forever.
- Run a dedicated circuit. Trivial now, an extra job later.
- Fix the outdoor unit position. Side or rear elevation, on brackets or a pad, away from bedroom windows (yours and the neighbours'). Decided now, it's tidy; decided later, it's a compromise.
At completion
- Indoor units mount, the system is commissioned by an F-Gas certified engineer, and the warranty gets registered. Done before you move in.
What it costs in a build
Equipment prices are the same as any install: the saving is in labour and finish. Realistic figures for a self-build:
- Single split for one room (an attic room or office): €2,000 to €3,000 in a build context
- Multi-split covering 2 to 4 rooms: €4,500 to €7,500
- Ducted whole-floor or whole-house: €10,000 and up, only sensible when designed in
Full pricing details and what a fair quote itemises are in the cost guide; room-by-room sizing is in the BTU guide.
Talking to your builder about it
Most Irish builders haven't done many AC installs; the technology is arriving faster than the trade habits. Practical advice: don't ask your builder to price "air conditioning" as a line item. Get a specialist AC installer to design and quote the system, then have them coordinate with the builder's electrician and plumber for first fix. It's one extra trade on site for two short visits, and every one of them has worked alongside other trades before. The builder pours no extra concrete; the electrician runs one extra circuit; the AC crew does the rest.
Common questions
When should I plan air conditioning in a new build?
At design stage, and no later than before first fix. That's when pipe routes, condensate drains, unit positions, and a dedicated electrical circuit can be built in cleanly, coordinated between the AC installer and your electrician and plumber.
Is it cheaper to install AC during a build than to retrofit?
Meaningfully. Retrofitting means surface trunking or chasing pipework into finished walls, typically €200 to €500 extra per indoor unit. During the build, routes are built in. Equipment costs the same; the labour and finish are cheaper and better.
Do new builds in Ireland really need air conditioning?
Increasingly, yes for some rooms. New Irish homes are airtight and heavily glazed, and overheating is a recognised problem, particularly south-facing rooms, attic rooms, and home offices. Cooling two or three vulnerable rooms is becoming a standard self-build decision.
Multi-split or ducted for a new build?
A build is the one time ducted is genuinely on the table, because ceiling voids can be designed for it. It's invisible and quiet but €10,000+. Most Irish self-builds land on a multi-split covering two to four rooms at €4,500 to €7,500.
Building now or breaking ground soon?
Tell us about the build and your timeline, and we'll match you with a vetted installer who'll design the system and coordinate with your builder for first fix. Free, no obligation.
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