Development consisting of the construction of a single storey extension at ground floor level to the rear of existing dwelling at No. 1 Longford Terrace, (A protected structure). Demolition of existing single storey extensions to rear at garden level and cellar store at basement level. Removal of existing window at ground floor level to rear reception room and alterations to same to access proposed extension. Alterations to rear ground floor staircase window to accommodate proposed rear extension. Extension of existing basement office use to the rear with associated new external staircase along western boundary and external open landscaped court to southern boundary. Removal of existing rear window to south elevation at basement level to accommodate extension. New utility at basement level for existing dwelling above, change of use of existing internal staircase at basement level from office use to dwelling use to provide access to new utility area at basement level. Minor alterations internally to existing basement office to accommodate new wc and lobby, new opening created in existing wall between front and rear office spaces. 3 no. new replacement up and down painted timber sash windows to rear elevation at 1st and 2nd floor levels to match existing. Existing boundary wall onto Clifton Avenue to be demolished and rebuilt to match existing with new replacement gate in boundary wall onto Clifton Avenue. Existing boundary wall to east and south between no. 1 and 2 Longford Terrace to be underpinned. Associated site works and landscaping. 3 no. car spaces to front garden along with 2 no. covered bicycle spaces to open office entrance area at basement level. Retention of change of use of ground floor office space and apartment at 1st and 2nd floor levels to a single dwelling which included minor refurbishment works internally, including insertion of kitchen to rear office room at ground floor level all at No. 1 Longford Terrace, Monkstown, Co. Dublin (A protected structure).