The research, conducted by Parity Projects for the UKGBC and the WWF, said bringing properties up to the minimum standard could save tenants £409 a year on energy bills and the cost of making the changes would be on average £1,421.

Under the Energy Act 2011, landlords are obliged to upgrade the worst performing privately rented homes – those with an energy performance certificate rating in band F or G – to a minimum energy efficiency standard from April 2018.

The research examined 3,000 properties rated in band F and G and costed the improvements required for the homes to reach band E without resorting to measures which require planning permission. It also found more than 70 per cent of the properties could reach band E for less than £1,000.

The average cost found by Parity Projects’ research is less than previous studies have shown – Consumer futures said only 39 per cent of band F and G properties can be improved for less than £1,500 per property and the Energy Saving Trust study found that 74 per cent of private rented homes banded F or G could be brought up to an E standard for less than £3,500 per property.

Paul King, chief executive of the UKGBC, said: ‘This research shows just how easy and affordable it will be for landlords to comply with the minimum standards, with improvements that won’t need to go through the planning system which can be costly and time consuming.

‘Minimum standards are a complete no-brainer – they require only the most basic and cost-effective improvements to a home but could save hundreds of pounds a year to the tenant. The government must introduce the regulations without delay to give badly needed certainty to both landlords and tenants.’