LL40 is below average for energy efficiency — most homes here have room to improve.
21.8% of homes are rated F or G — above the national average of 2.9%.
Energy efficiency in LL40 (Gwynedd) sits at an average score of 53 out of 100, placing it below the national average. To put this in context, the national average sits at 67. The most common rating band is D, with 2.8% of homes rated A or B and 53.3% in the C or D bands. Meanwhile, 21.8% 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.
Most of the housing stock here consists of houses. Around 70% of properties are owner-occupied and 18% are social housing. Gas central heating is the main fuel source for 53% 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 53 to 79 — a 26-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 LL40 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: 79 (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 LL40?
Homes in LL40 have an average EPC rating of E, scoring 53 out of 100 for energy efficiency. That figure comes from 1,423 certificates issued across the district.
That is below the national average of 67, which means there is real scope to improve energy efficiency here. An E rating suggests many homes here are losing significant amounts of heat — and money — through poor insulation or outdated heating systems.
What percentage of homes in LL40 are rated F or G?
21.8% of homes in LL40 fall into the F or G bands — the lowest energy efficiency ratings. Nationally, the figure is 2.9%.
That means LL40 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.