The Land Development Agency (LDA) has struck a deal to acquire what will be the tallest building in Ireland from Joe O’Reilly’s development firm Castlethorn.The State’s affordable housing developer, led by John Coleman, has agreed a deal to buy 562 homes in the new apartment project on Parkgate Street in Dublin, which is due to be completed in 2029.John Paul Construction will act as lead contractor on development. The agency would not comment on the financial aspect of the deal. The apartments are expected to cost close to €220 million to build.Some construction work has already begun on the site, located beside Heuston Station, which will include a 30-storey, 102-metre residential building.The 30-storey block will be taller than the 85m-high Obel Tower in Belfast and the in-development 85.53m Railyard building in Cork. It will include 198 apartments. The remaining apartments on the Parkgate Street site will be spread across three blocks from 10 to 13 storeys.A spokeswoman for The LDA said the deal with Castlethorn would “unlock a long-underutilised site”. She said the LDA’s backing of the Parkgate Street development would help stimulate a wider regeneration project in the area.In addition to the deal with Castlethorn, the LDA and CIÉ have agreed a memorandum of understanding to progress design work on a mixed-use master plan for the land around Heuston Station. Developer Joe O'Reilly spent in excess of €30 million to buy the site beside Heuston Station in 2018. In recent years, the LDA has become one of the largest developers in the State. It has more than 6,500 homes under construction on more than 20 sites. Coleman said the agency would complete 1,800 new homes this year, nearly 3,000 next year and more than 3,500 in 2028. On average, it is spending €430,000 to build each of these 8,300 homes, or close to €3.5 billion in total.The deal with Castlethorn is being funded by the LDA through its Project Tosaigh initiative, which allows the agency to buy large residential projects from private developers.The Parkgate Street site was acquired by O’Reilly for in excess of €30 million, or just under €18.2 million per acre, in 2018. His firm has made a number of planning applications in recent years to develop the 0.67 hectare site, formerly occupied by Hickey’s Wholesale Fabrics. The deal for the Parkgate Street development is the second arrangement Castlethorn has agreed with the LDA. O’Reilly’s development firm previously agreed to sell 328 new apartments at its Woodbrook site in Shankill to the LDA for cost rental housing.A spokeswoman for Castlethorn said its latest deal with the LDA “reflects Castlethorn’s commitment to working with trusted partners to unlock complex sites and create great places that will serve communities for generations”.Castlethorn, one of the largest private developers in the country, is active on 10 residential construction sites at present. Developer Castlethorn has secured planning permission to build a 30-storey residential tower on the site beside Heuston Station. Photograph: LDA / Castlethorn Earlier this year, the firm’s group managing director Ronan Columb said its active sites in the Greater Dublin Area have capacity to deliver close to 6,000 homes.Last month, the developer confirmed it has agreed a funding deal with Avenue Capital that will involve the US firm investing up to €100 million from its new housing fund into a joint venture with Castlethorn. The funding is expected to support the delivery of more than 7,000 homes.