Side extension planning approval in Lisburn and Castlereagh
Based on decisions in the last 5 years, as of 24 Jun 2026.
We hold no refused side extension decisions for Lisburn and Castlereagh in this period, so treat a full approval rate with caution. The council's own portal has the complete record.
Of 59 side extension planning applications decided by Lisburn and Castlereagh in the last 5 years, 100% were approved. This is the council's track record for this kind of work. It is a useful gauge before you apply, not a guarantee for any one application.
Other work in Lisburn and Castlereagh
- Extension : 99% approved (363 decided)
- Rear extension : 100% approved (107 decided)
- Demolition : 98% approved (52 decided)
- Two-storey extension : 100% approved (40 decided)
- Loft conversion : 98% approved (44 decided)
- Change of use : 95% approved (22 decided)
- New dwelling : 89% approved (28 decided)
- Boundary wall / fence / gates : 100% approved (31 decided)
Method
Approval rate = approved ÷ (approved + refused) over the public planning decisions we hold for Lisburn and Castlereagh, matched to a type of work from the application description. We lead with the last few years so the figure reflects how Lisburn and Castlereagh decides today, with the longer record as context. A rate is only shown once there are enough decided applications for it to be reliable. We publish aggregate figures only, never an individual application or applicant name. Read the full method and limits.