SO21 is around the national average for energy efficiency.
5.2% of homes are rated F or G — above the national average of 2.9%.
The 5,739 EPC certificates on record for SO21 paint a clear picture — the area averages 64 out of 100, placing it around the national average. The national average is 67, which means SO21 performs roughly in line with the rest of the country. The most common rating band is D, with 10.8% of homes rated A or B and 66.5% in the C or D bands. Meanwhile, 5.2% of homes sit in the F or G bands — the least efficient categories. In practical terms, a rating of D means many homes here lose more heat than average — potentially adding £200-400 per year to energy bills compared to a C-rated home.
Houses make up the bulk of the housing in this district. Around 70% of properties are owner-occupied . Gas central heating is the main fuel source for 67% of homes, which is typical for urban areas across England.
There is genuine room for improvement here. If every recommended upgrade were carried out, the average score could climb from 64 to 80 — a 16-point jump that would lift the typical rating to C. That is a substantial gain, suggesting many homes are missing basic efficiency measures. If you live in SO21 and want to reduce your energy bills, start with our guide to loft insulation — it is one of the most cost-effective upgrades you can make.
EPC Rating Distribution
Energy Efficiency Score
Potential score if all improvements made: 80 (rating C)
Recommended Improvements
Government funding may be available for some of these improvements. Check grants →
More data — property types, tenure & fuel
Property Types
Tenure
Main Fuel Types
Frequently asked questions
What is the average EPC rating in SO21?
Homes in SO21 have an average EPC rating of D, scoring 64 out of 100 for energy efficiency. That figure comes from 5,739 certificates issued across the district.
This is broadly in line with the national average of 67 — neither particularly efficient nor particularly wasteful. A D rating typically means higher-than-necessary heating bills, especially in older properties without adequate insulation.
What percentage of homes in SO21 are rated F or G?
5.2% of homes in SO21 fall into the F or G bands — the lowest energy efficiency ratings. Nationally, the figure is 2.9%.
That means SO21 has a higher-than-average proportion of poorly insulated homes. On the positive side, many of these properties may qualify for free improvements through government schemes like ECO4 or the Great British Insulation Scheme. Landlords should note that F and G rated properties cannot legally be rented out under current MEES rules.