59 Sibley Avenue Harpenden Hertfordshire AL5 1HFReference5/2026/0594Local authoritySt AlbansAddress59 Sibley Avenue Harpenden Hertfordshire AL5 1HFProposalDouble storey front, side and rear extension and loft conversion including raising of ridge height. Crown roof with side and rear dormers. Alterations to openings at 59 Sibley Avenue Harpenden Hertfordshire AL5 1HFStatusRefusedDecision date2026-06-25Validated2026-03-25More planning applications in St Albans