A report into an €800,000 project to revamp a park entrance said a quadrupling of costs stemmed from bespoke items including Portuguese granite and design specifications that “fell short” of what was needed.
The assessment said preliminary documents had offered a major underestimate of what would be involved in the project at the park in South Dublin.
It said future projects should be managed differently as the works were at one stage expected to cost just €200,000, according to a grant application.
The report said a substantial number of additional resources were required to complete the project beyond what was expected.
This included “bespoke items” like special Portuguese Alvo granite paving, restraining systems, and benching units.
It said substantial remeasurements of the scheme were required because of “inaccuracies and lack of information” in the original proposals.
The report said costs mounted even further as it became clear measures would be needed to protect trees and to avoid issues with underground pipes and wiring.
It explained: “The interference of underground utilities with the works and the extra costs and time required to provide alternative design solutions were deemed inevitable.
“The level of accuracy of the underground services maps was limited, and the exact location and number of said services could only be ascertained at construction stage.”
The report – prepared by an external consultant – said a later execution estimate for the works was around €416,000, of which €321,000 was allocated for construction.
However, by the end of 2025, the estimated actual cost of the works had risen to €848,000.