Read This Before You Call Anyone. At some point, almost every homeowner in Dublin reaches the same crossroads: move, or extend. Moving is expensive, disruptive and stressful. Stamp duty, legal fees, agent fees, the nightmare of finding something you actually like in an area you actually want. For a lot of families particularly in established southside suburbs where the school, the community and the decade of invested garden are hard to walk away from extending makes far more sense. But here’s the thing: a bad extension is worse than no extension.
Done badly, it creates damp, structural issues, planning headaches, and a finish that drags down the value of your home rather than adding to it. Done well, it transforms how you live and adds real money to your property in one of the most competitive housing markets in Europe. The difference almost always comes down to who builds it. What kind of extension are you actually looking for? Before you start talking to extension builders, it helps to know what you’re dealing with. There are a few main types of house extension that come up repeatedly in Dublin and each has its own character, constraints and cost profile.
The rear extension The most common type in Dublin, and for good reason. A rear extension whether it’s a single-storey kitchen-diner or a larger open-plan living space fundamentally changes how a house works. It brings the back garden into the living space, creates the flow that older Dublin houses were never designed for, and usually delivers the best return on investment. Popular across Ranelagh, Rathmines and Harold’s Cross, where the original rear rooms are often dark and disconnected from the garden. The side return extension Many Victorian and Edwardian terraces have a narrow side passage that strip of dead space running alongside the kitchen. Infilling it creates a surprisingly large amount of floor area, and when it’s glazed properly it floods the whole rear of the house with light. If you’re in Rathgar, Terenure or Clontarf and you’ve got a side return, it’s almost certainly worth exploring.
The double-storey extension If you need more bedrooms or want to create a proper main bedroom with an en suite a double-storey extension delivers both floors in one project. It’s a more complex undertaking structurally, but the space gain is significant and the cost per square metre is lower than doing two single-storey projects separately. Phoenix Maco Ltd regularly delivers these across Drumcondra, Dundrum and the wider northside and southside suburbs. The wraparound Combining rear and side return into a single L-shaped extension, the wraparound gives you the maximum possible ground floor space. These work particularly well on the semi-detached homes common across Terenure, Templeogue and parts of Clontarf, where there’s room to expand in two directions without compromising the garden too badly. What actually makes a good extension builder in Dublin?
The internet is full of advice about getting three quotes and checking reviews. All of that is fine. But there are a few less obvious things worth paying attention to when you’re evaluating extension builders in Dublin. First: how do they talk about structural work? Any rear or side return extension involves removing walls and installing steels. If a builder glosses over this treats it like it’s routine and barely worth mentioning that’s a flag. Structural openings done badly are expensive to fix and create long-term problems. You want a builder who takes them seriously. Second: who coordinates the trades? A well-run extension project has a plumber, electrician and builder all working in a defined sequence. If the builder expects you to manage that yourself, you are effectively the project manager of your own extension — a job most homeowners haven’t signed up for and aren’t equipped to do. Phoenix Maco Ltd coordinates electrical and mechanical works within the project scope, which keeps the programme moving and avoids the gaps that cost time and money. Third: look at their finish. Not just photos actually go and see a completed project if you can. The signs of a quality finish are in the details: straight lines where the old and new construction meet, clean reveals around windows and doors, level floors, tidy junction between the extension roof and the existing building. These things don’t happen by accident.
They happen because a builder prepared correctly before any finish went on. That prep-first approach is central to how Phoenix Maco Ltd works. The standard of a finish is set weeks before it’s visible in the accuracy of the set-out, the quality of the substrate, the care taken at every junction. It’s what separates an extension that looks right and holds up from one that starts showing problems within a year. Do you need planning permission for a house extension in Dublin? Probably not for a single-storey rear extension but it depends. Under Irish planning law, single-storey extensions can often be built as exempted development, meaning no planning application is required.
The size limits, however, are more restrictive than people often assume, and there are additional constraints if your home is in a protected structure area or on a corner site. Double-storey extensions almost always require planning permission. So do extensions that affect the front elevation. Phoenix Maco Ltd gives honest feasibility guidance at the start of every project. Before you commit to anything, you’ll know what’s achievable on your site, whether a planning application is likely to be needed, and what timeline to realistically expect. It’s a simple conversation and it saves a lot of trouble down the line. What does a house extension actually add to your property value? In Dublin’s current market, a well-executed extension consistently adds more in property value than it costs to build. In high-demand suburbs Ranelagh, Rathmines, Ballsbridge, Donnybrook, Sandymount, Blackrock, Booterstown, Mount Merrion a properly extended home commands a significant premium over an unextended equivalent. The keyword there is properly. An extension with damp issues, poor structural detailing or a finish that visibly clashes with the existing house can actually hurt a sale. Buyers and their surveyors notice. Estate agents notice. The valuation reflects it. This is why the choice of extension builder in Drumcondra, Dundrum or Clontarf is a financial decision as much as a building one. Get it right and you’ve added real, durable value.
Get it wrong and you’ve created a problem someone else will eventually have to fix. How to get started with Phoenix Maco Ltd It’s genuinely straightforward. WhatsApp them a few photos or a short video of your home, tell them your area whether that’s Ranelagh, Rathmines, Harold’s Cross, Rathgar, Terenure, Templeogue, Clontarf, Drumcondra or Dundrum and explain what you’re trying to achieve. They come back with real feasibility advice and a clear sense of the next step, whether that’s a call, a site visit, or a formal quote. No obligation, no sales pressure. Just a straight conversation from people who know what they’re doing.
Phoenix Maco Ltd Building Block 9B, Heuston South Quarter, The Kestrel, St John’s Rd W, Dublin 8, D08 TD98 📞 +353 87 004 3470 🌐 macoltd.ie
