G

EPC Rating G Explained

Very poor energy efficiency (1-20)

An EPC rating of G is the lowest possible rating, indicating very poor energy efficiency. G-rated homes have extremely high energy costs of around £3,600 per year—more than four times an A-rated property. Only about 3% of UK properties have a G rating. These properties cannot be legally rented and require substantial investment to improve.

1-20
Efficiency Score
£3600
Typical Annual Cost
7t
CO₂ per Year
3%
of UK Properties

What Does an EPC Rating G Mean?

A G-rated property has the worst possible energy efficiency with severe heat loss and highly inefficient or absent heating systems. These homes are very expensive to heat, often cold and uncomfortable, and have a significant carbon footprint.

G-rated properties represent the bottom 3% of UK housing stock. They cannot be legally rented and face the biggest challenge for improvement. Many are historic buildings with solid walls and listed status that limit improvement options.

Typical Properties with Rating G

1

No central heating or very old system

2

Solid walls with no insulation

3

No loft insulation

4

Single glazing or missing windows

5

Major structural heat loss

6

Often pre-1900 construction

Energy Costs for G-Rated Properties

Properties with an EPC rating of G typically cost around £3600 per year to heat and power, based on current UK energy prices.

Monthly estimate: £300
vs National avg (D):Extra £1800/year

How to Improve from Rating G

G-rated properties need comprehensive renovation. A whole-house approach is usually most cost-effective:

1

Solid wall insulation

Internal or external insulation essential

Cost: £10,000-£30,000Savings: £600-£1,000/year
2

Install central heating

Modern heating system if not present

Cost: £3,000-£15,000Savings: £500-£800/year
3

Full loft insulation

Install 270mm+ throughout

Cost: £400-£1,000Savings: £300-£500/year
4

Complete window replacement

Double or triple glazing throughout

Cost: £5,000-£15,000Savings: £200-£400/year
View complete improvement guide

Can I Rent a Property with Rating G?

Cannot be legally rented

G is below the minimum E standard for rental properties. Significant improvement required.

Under the Minimum Energy Efficiency Standards (MEES), landlords in England and Wales cannot grant new tenancies for properties rated F or G unless they have a valid exemption. The government has proposed increasing this minimum to C by 2030.

Frequently Asked Questions

Is G the worst EPC rating?

Yes, G is the lowest possible EPC rating, with scores of 1-20 out of 100. Only about 3% of UK properties have a G rating.

How much does it cost to improve a G-rated property?

Comprehensive improvement typically costs £15,000-£50,000+ depending on the property type and condition. Grant funding may be available.

Are there grants for improving G-rated homes?

Yes, various grants exist including ECO4, the Great British Insulation Scheme, and local authority funding. G-rated homes often qualify for maximum support.

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