Ronan Columb: New housing policies must be implemented more swiftly to unlock homes
With 3,500 units on-site and a focus on large-scale placemaking, Castlethorn Group Managing Director Ronan Columb speaks with ROBBIE COUSINS about leveraging MMC, delivering vital infrastructure, and the urgent need for the state sector and local authorities to accelerate the pace of policy implementation.
Castlethorn, one of Ireland’s foremost real estate developers and home builders, is experiencing a significant resurgence, positioning itself at the forefront of the nation’s ambitious housing drive. After navigating the cyclical nature of the construction industry, the company is back on a steady upward trajectory.
Group Managing Director, Ronan Columb, who took up his leadership role in 2023, is steering the 35-year-old firm with a clear, strategic focus on large-scale residential delivery and transformative placemaking.
With thousands of units currently on-site and an extensive development pipeline, Castlethorn is not just building homes; it is constructing entire communities, often requiring the delivery of major public infrastructure—a level of complexity few in the market embrace. Columb’s insights reveal a business that thrives on solving challenges of scale, innovates through Modern Methods of Construction (MMC), and actively champions a collaborative approach to unlocking housing supply, while simultaneously highlighting the urgent need for the state sector to match the industry’s pace.
EMBRACING THE RESIDENTIAL GROWTH OPPORTUNITY
Castlethorn’s business evolution has seen it strategically pivot to meet current market demands. While the firm previously engaged in retail, commercial, and leisure developments, the core focus today is unequivocally residential.
Ronan Columb explains, “We have been very busy focusing on the residential side of our business for the last number of years, because, essentially, that’s where the growth opportunity is.”
This concentration is driving dramatic growth.
The numbers speak for themselves. Castlethorn is currently on-site with approximately 3,500 residential units, a figure projected to rise to about 4,000 in Q1 of next year. The pace of delivery is accelerating rapidly, with expected unit closings climbing from around 500 per year in previous periods to a target “cruising altitude” of circa 2,000 to 2,500 units annually by the end of next year. Furthermore, the company holds a substantial land pipeline spanning tens of thousands of potential units, underscoring its long-term commitment to high-volume housing delivery.
“We’re around a long time—over 35 years. We’ve had some highs in the past, and we’ve had some lows, and we’re back on the upcurve at the moment,” Columb notes, reflecting the company’s resilience and renewed energy. “This growth is intrinsically linked to our ability to manage and deliver complex, large-scale projects.”
PLACEMAKING AS A CORE BUSINESS STRATEGY
For Ronan Columb and Castlethorn, a development is defined by more than just the houses or apartments it contains. Placemaking—the creation of successful, integrated, and sustainable built environments—is the company’s “main ambition” and “greatest achievement.” This commitment is non-negotiable when operating at scale.
“Placemaking and infrastructure are things that come with scale of delivery,” he explains. “While small developments might not face significant infrastructure hurdles, projects involving thousands of units—like our Woodbrook development in Shankill, South County Dublin —place a far greater burden on the developer. We need to deliver more than just homes. We also have to deliver the custom supporting infrastructure for that.”
This is the kind of project where Castlethorn truly excels, a territory that may be new for some later market entrants but is deeply ingrained in the company’s heritage. Its involvement in Adamstown, a significant SDZ (Strategic Development Zone), serves as a prime example.
Acquired unzoned in the late 90s, Castlethorn guided the lands through the entire planning process, co-creating the Local Area Plan (LAP) and SDZ in conjunction with South Dublin County Council. Crucially, Castlethorn was responsible for the delivery of key physical and social infrastructure.
“We built the railway station in Adamstown, we spent €100m on infrastructure to develop the lands to enable them to produce units,” Columb explains. “Furthermore, the development included provisions and planning for a secondary school, two primary schools, and several creches.”
LAND ACQUISITION AND DEVELOPMENT STRATEGY
Castlethorn’s strategy has consistently been to acquire lands on key transport nodes, a foresight that now aligns perfectly with sustainable urban planning principles. This focus is evident across its portfolio:
– Adamstown, Lucan: A rail-based community where Castlethorn built the railway station in 2007.
– Woodbrook, Shankill: Castlethorn built a DART station to create another rail-based community.
– Rathborne Park, Ashtown, Dunlin 15: Castlethorn is building a community around an existing, underutilised railway station.
Successful developments, for Columb, hinge on delivering both physical infrastructure (pipes, squares, bridges) and social infrastructure (schools, creches, parks, and shops).
PROJECT PIPELINE AND FUTURE FRONTS
Castlethorn’s current workload spans every stage of the development process, securing its delivery pipeline for years to come.
At Rathborne, Dublin 15, the company has approximately 1,000 units on-site. The team is also actively working with the local authority to bring zoned lands in the immediate area into production, potentially yielding several thousand additional units. Furthermore, they are pursuing zoning for other owned lands in the area through the current or future development plans.
The Woodbrook, Shankill, site is nearing the completion of its final 600 units. However, Castlethorn has a significant interest in an adjacent land bank where the Old Connaught LAP has recently been adopted by Dún Laoghaire-Rathdown County Council (DLRCC). This site is being prepared to become one of the company’s “new fronts” from the end of 2026 onwards.
Kellystown, Dublin 15, is a new critical location, with work underway on existing lands and expectations of positive planning outcomes for additional plots, signalling an “extended future” for the company in that area. In addition to these largescale master-planned sites, a number of other higher-density projects are slated to commence on-site between now and the end of Q1 next year.
POLICY TO IMPLEMENTATION: THE CHALLENGE FOR THE GOVERNMENT
Ronan Columb acknowledges and welcomes many of the recent government policy announcements, believing they are “capable of producing higher levels of output across the industry.” However, the crucial point of friction remains the “gap between policy and implementation.”
Ronan Columb expresses concern that the policies are filtering down through the system at a slower rate than needed. He highlights that major intermediary bodies—including local authorities, utility companies, and government departments— do not always act with the same sense of urgency demonstrated by central government.
“The most important thing for us now is to see that the policies that the government is activating are implemented, and implemented swiftly, so that the industry can react and start building more residential units,” he stresses.
He has high hopes for the new Housing Activation Office and Housing Tsar, viewing this as a potential “good force for change” capable of unblocking persistent issues and accelerating policy implementation.
He argues that many state bodies were designed for regulation and control, but the current imperative demands a shift to an enabling, encouraging mindset—a change the Housing Activation Office should foster.
Interestingly, he says that Castlethorn conducted its own internal “school report” on the government’s progress against a wishlist developed at the beginning of the year.
“I am really pleased to say that in many respects the government hit the mark on many things, including changes to the guidelines concerning judicial reviews (JRs), even if the path taken wasn’t always precisely what we had envisioned. Change must be “controlled and incremental, and while not always popular, the cumulative impact is to improve output”.
RISKS AND ROADBLOCKS TO DELIVERY
Despite positive government moves, significant operational and systemic risks continue to pressure developers like Castlethorn.
While acknowledging that Judicial Reviews are a “vital piece of our democratic process,” Roan Columb stresses, “the presence of them and the possibility of them really puts a lot of pressure on businesses like ours. The cost of preparing planning applications has multiplied over the past few years, as developers are compelled to take so many additional measures to try and obviate the risks of a potential JR. If changes to the judicial review process are not implemented effectively, there will be stunted progress on apartment delivery for many, many years to come.”
INCONSISTENT LOCAL AUTHORITY ENGAGEMENT
A key challenge is the inconsistency of planning rules and regulations across different local authorities. Ronan Columb observes a stark divide: “Some authorities are pro-development, very helpful, and have a sense of mission of collaboration and cooperation. Other local authorities have more of a controlling and regulating mentality and are more inclined to find reasons not to grant than they are to find reasons to grant.”
He questions why, in an environment with a national sense of urgency, all local authorities are not operating on the basis that they should be “Trying to grant permissions rather than looking for reasons for refusal or looking for reasons to delay through further information requests.”
UTILITIES: A WELCOME SEACHANGE
One area where Ronan Columb has seen significant, positive improvement is in engagement with utility companies over the past 12 months.
He comments, “Where engagement was previously focused on protecting and controlling their network, utilities are now trying to find ways of getting us access to their network. This fundamental shift is a sea-change that is to be welcomed.”
PIONEERING MODERN METHODS OF CONSTRUCTION
Castlethorn has a long-standing reputation as an industry disruptor, always looking to pioneer different and more efficient ways of building. This approach is central to its current strategy using Modern Methods of Construction (MMC).
The company generally utilises a hybrid approach to construction:
– Houses: Built using advanced timber frame, manufactured in factories, delivered to site in “flat packs”, and quickly erected.
– Apartments: Typically designed to be built using precast concrete, also fabricated off-site and assembled.
The company exploits MMC to the maximum extent, provided that, according to Columb, “value is preserved”.
“While the elemental cost may sometimes be higher, the gains in productivity, certainty of quality, and labour management make it worthwhile.”
Columb highlights the speed advantage. “Once a timber frame house is erected, roofed, and windowed, a weatherproof shell is achieved within a week, allowing internal finishing to commence quickly.”
Ronan Columb says Castlethorn is now looking for the “next incremental step” in MMC.
“The current bottleneck is external finishing, which requires wrapping the building in scaffolding. This delays the completion of groundworks, adding time and cost. We are actively seeking an MMC solution that eliminates the need for scaffolding on external facades, enabling quicker site access and faster home delivery. Time on-site is one of the highest costs now for us in terms of the delivery component.”
While there is significant innovation in the MMC space, a viability gap persists. New products often carry an elemental cost that is a “fraction of the cost of buying this as a composite unit.”
On the next iteration of MMC, Ronan Columb adds, “For a housing market already challenged on viability, particularly for apartments, any innovation must reduce costs, not destroy value.
THE POWER OF COLLABORATIVE INFRASTRUCTURE DELIVERY
Castlethorn is not waiting for the public sector to address all major infrastructure deficits. Their work on the Port Access Northern Cross Route (PANCR) in Drogheda serves as a powerful, proven template for collaboration. Completed in March 2024, the PANCR is more than a road; it is the enabling infrastructure for up to 5,000 new homes north of Drogheda.
Louth County Council had struggled to deliver this road for 20 years. Castlethorn proposed an innovative model, partnering with the local authority and the Housing Infrastructure Services Company (HISCo), which funds enabling infrastructure that is often difficult to finance traditionally.
“From the first day we mooted it with the local authority to the day we cut the ribbon and opened the road, I think it was probably no more than 24 months,” says Columb.
The result is a powerful catalyst. Castlethorn is now building thousands of units at Ballymakenny Park, and Ronan Columb observes that for every 100 units Castlethorn builds, at least another 100 are being built nearby by smaller developers.
“This template proves the effectiveness of industry-led, collaborative infrastructure delivery, which is a much more efficient way of delivering infrastructure than going through public procurement. The challenge, however, is that this model requires an open-minded and creative local authority leadership team, and a ‘can-do’ and will-do attitude, which “we don’t see enough of.”
LEADING THE WAY IN SUSTAINABILITY
Sustainability has always been a hallmark of Castlethorn’s innovative approach. The company was involved in one of the first House of Tomorrow schemes with SEAI in Adamstown in 2005 and delivered the country’s first NZEB (Nearly Zero Energy Building) scheme in Riverwood Square in 2019.
“We have always felt that it was part of our role to innovate and get ahead of the regulations as they came along,” states Ronan Columb. “We are currently exploring the next step forward, whether that focuses on carbon reduction, envelope efficiency, or renewable energy. Whatever it is, our commitment is clear: You will see Castlethorn homes that are delivered in the near future being delivered to a higher sustainability standard than the current regulations require.”
While Castlethorn has availed of Green Finance, Ronan Columb notes that the cost of qualifying sometimes outweighs the small financial incentive. For now, the primary business reality is the bottom line, which allows for investment in future projects. He believes that for true innovation to flourish, the cost differential between green and regular finance needs to be substantially greater over time.
THE CRITICAL NEED FOR PUBLIC SECTOR ALIGNMENT
Ronan Columb’s greatest concern remains. “One key issue that risks derailing our company’s ambitious delivery targets is the pace of movement of the state sector and local authority sector.
“Castlethorn is growing, investing in our business and our people at a rate designed to deliver significantly more units in a shorter period. We still don’t see that pace being matched on the public side, and this is cause for concern for the sector as a whole.
“If the pace of implementation and processing by public bodies does not accelerate, Castlethorn will face the undesirable choice of having to slow down or reduce in scale, which, in the context of the country’s housing crisis, would be all the wrong things to do.”
IN CONCLUSION
Castlethorn has demonstrated its ability to deliver thousands of homes, along with the necessary infrastructure, through innovative, large-scale placemaking models. The company’s long history of disruption, commitment to MMC, and proven collaborative delivery models position it as a critical engine for Irish housing supply.
Ronan Columb closes by saying, “The ball is now firmly in the court of the intermediary state bodies to adopt the ‘can-do’ mindset and match the industry’s urgency, ensuring that policy translates swiftly into action and that Castlethorn, and the wider sector, can reach our potential for the benefit of the national housing effort.”