CM21
Outer Postcode Area • 484 PostcodesWorking on listings or site checks?
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Investment Metrics & Statutory Planning for CM21
Sold price per square foot, indicative gross yield, Article 4 status and ground stability, from official open data.
HM Land Registry & EPC Data
Area rent ÷ area price, indicative
Conservation area controls apply
British Geological Survey
Property Investment Yields & Valuation Metrics
HM Land Registry Price Paid & ONS Private Rental Statistics
Planning constraints
planning.data.gov.uk (DLUHC) & Historic England
- Article 4 direction
- Not published
- Tree preservation zone
- Not published
Some permitted development rights are restricted here, so changes may need planning permission.
- East Hertfordshire has not published Article 4 direction areas to planning.data.gov.uk, so they could not be checked.
- Inside the Sawbridgeworth conservation area: stricter controls on external changes, demolition and tree works.
- 14 listed building(s) within 100m (nearest: Grade II STABLE BLOCK AT NUMBER 4, 18m). Work affecting their setting may need extra consent.
Spatial screening uses the postcode centroid. Properties on boundaries must be checked against the council’s own maps.
Ground Stability, Subsidence & Radon Hazards
BGS & Coal Authority Public Registers
Data quality: Aggregated across 484 constituent postcodes
484 official/live sections, 0 fallback sections, 0 missing or limited sections. Generated 8 Oct 2026, 11:51.
Frequently Asked Questions
Official open-data answers about safety, schools, connectivity, and living in CM21.
Is CM21 a good place to live?
CM21 in East Hertfordshire scores 61.8/100 overall in the Postcodewise area report, which combines safety, schools, transport, housing, demographics, environment and connectivity from official open data.
What is the crime rate in CM21?
The CM21 report shows recent police-recorded crime levels and trends in East Hertfordshire, sourced from Police.uk street-level data.
What schools are near CM21?
The CM21 schools report lists nearby primary and secondary schools with Ofsted-linked ratings and distances.
How well connected is CM21?
The CM21 report covers nearby transport links, broadband speeds and mobile coverage for the area.
Explore nearby areas
Open area reports for postcodes and streets close to this one.