Side extension planning approval rate in Hertsmere
84% of 702 decided side extension applications in Hertsmere were approved.
Checked against 20.6 million UK planning applications on file across 420 planning authorities. Approval rates from 2,343,419 decisions we classified across 181 councils in England.
A similar project nearby can help you understand the council's decisions. Its outcome does not establish what will be acceptable at your address.
84%
Approval rate, all years, from 702 decided
702
decided side extension applications in Hertsmere: 590 approved, 112 refused
86%
Recent rate, decided since 2022, from 217 decided
How to read these rates
These are historical outcomes for the applications in our archive, not the chance of approval for your property. Compare the same project type and read the decided count alongside each percentage.
About the planning data
Rate = approved divided by approved plus refused, using the decisions in our classified archive. Rates are withheld as unknown where fewer than 8 records of that project type were decided. Withdrawn applications are excluded. The eight-record threshold is a display rule, not a guarantee that a sample is statistically reliable.
Recent means records dated 2022 or later. Records without a year are excluded from the recent rate but remain in the all-years figure. Historical coverage varies by council, and duplicate application references may remain in the archive.
Approval rates from 2,343,419 decisions we classified across 181 councils in England. The wider 20.6 million application catalogue is accessible through PlanIT; it is not the dataset used to calculate these percentages.
Read the full methodology and coverage notes.
Project types and outcomes are classified from council records. Check the original application and decision notice before relying on an individual example. A page rebuild does not mean every council record has just been refreshed.
Coverage for this project type
Dated records in this archive span 2015 to 2026. 0 of 702 decided records have no year recorded. Coverage may have gaps within the date range.
217 decided records are dated 2022 or later. This is an archive count, not a measure of all current council activity.
These project categories can include different application routes and proposals combining several kinds of work. Read the proposal and decision type before comparing it with your project.
Check planning requirements in Hertsmere, or read about permitted development in Hertsmere. An approval rate does not decide which route your property qualifies for.
Example side extension decisions in Hertsmere
These examples deliberately include approved and refused applications where available. They are not a representative sample or a list of the latest decisions. Look up each reference on the council's planning search to read the plans and decision notice.
Search Hertsmere's planning register using the references below. Descriptions may be shortened; read the complete proposal and decision notice.
| Reference | Year | Decision | Application |
|---|---|---|---|
| 25/0305/HSE | 2026 | Approved | Single story side extension, conversion of loft to habitable space including 1x side dormer and 1x rear dormer, alterations to fenestration and replacement o... 48 Elmroyd Avenue Potters Bar Hertfordshire EN6 2EE |
| 25/0461/HSE | 2026 | Approved | Construction of single storey side extension with associated roof works (as amended by plans received on 07.08.2025, 18.12.2025 and 13.02.2026). 48 Oakroyd Avenue Potters Bar Hertfordshire EN6 2EL |
| 25/1634/HSE | 2026 | Approved | Conversion of garage to habitable space, with window to replace garage door and replacement roof, construction of side extension and new flat roof over exist... 42 Richfield Road Bushey Hertfordshire WD23 4RQ |
| 25/1833/HSE | 2026 | Refused | First floor side extension. 14 Tilehouse Close Borehamwood Hertfordshire WD6 4AS |
| 24/0858/HSE | 2025 | Refused | Two storey side extension and new vehicular crossover. 7 Stamford Close Potters Bar Hertfordshire EN6 5NW |
| 24/1568/CLP | 2025 | Refused | Construction of single storey side extension. Certificate of Lawful Development (Proposed). (AMENDED PLAN RECEIVED: 21/01/2025 - site plan updated to match p... Alvina Aldenham Road Elstree Borehamwood Hertfordshire WD6 3BD |
About the planning data
Checked against 20.6 million UK planning applications on file across 420 planning authorities. Approval rates from 2,343,419 decisions we classified across 181 councils in England.
Other project types in Hertsmere
- Single-storey rear extension 81%, 1,787 decided
- Two-storey rear extension 85%, 972 decided
- Wraparound extension 92%, 436 decided
- Loft conversion and dormer 79%, 281 decided
- Rooflight 90%, 918 decided
- Outbuilding and garden room 78%, 274 decided
- Porch 90%, 195 decided
- Garage conversion 96%, 294 decided
- Basement 84%, 136 decided
- Window and door 90%, 223 decided