By Clara Finn
The High Court has quashed planning permission for an office development at 94 and 95 Mount Street Lower and Love Lane in Dublin 2 after finding that An Bord Pleanála failed to adequately explain its decision on daylight and sunlight impacts.
Palatine DAC, the owners' management company for the neighbouring Grattan Hall residential development, challenged permission granted to Mount Way Offices Limited in September 2022.
The project began as an eight-storey over basement office proposal. It was reduced to seven storeys during the Dublin City Council process and then to six storeys over basement on appeal. Dublin City Council had refused permission, citing the proposed building's scale, height, massing, overlooking and overshadowing effects.
An Bord Pleanála's inspector also recommended refusal. On daylight and sunlight, she found that the developer's assessments had not satisfactorily demonstrated that neighbouring properties would avoid undue adverse impacts. Among the issues was the use of a 20% Vertical Sky Component threshold instead of the 27% figure referred to in BRE guidance, together with concerns about omitted windows and incomplete assessment of adjoining homes.
The Board nevertheless granted permission. It accepted that neighbouring buildings would experience overshadowing but concluded that the cumulative effect would not amount to an undue negative impact given the built-up city-centre location.
Farrell J held that the Board was entitled to disagree with its inspector. However, where it did so, it had to explain why. The court found that the Board gave a conclusion but did not explain why it considered the developer's methodology sufficiently reliable, despite the inspector's findings and objections from neighbouring residents.
The judge said an affected party was entitled to understand the main reasons on this central issue, and the court itself needed enough reasoning to review the decision lawfully.
Because that failure was sufficient to invalidate the permission, the court did not decide the remaining challenges. The Board's September 2022 permission was quashed, with consequential matters listed for 13 October 2025.