From 2025, all newly rented properties will be required to have an EPC rating of C or above.
Currently, properties only require an EPC rating of E or above. Existing tenancies will have until 2028 to comply with the new rule changes.
A quarter (25%) of landlords surveyed said they had little to no knowledge of the forthcoming changes to the required EPC rating.
With a large proportion (36%) of landlords with properties built pre-1940, Shawbrook’s analysis showed that a significant number of landlords will be required to make changes.
On a regional level, four in 10 landlords said that their properties in London were built prior to 1940, with a similar picture in the South West, Scotland and Wales.
Victorian properties make up 13% of private rental housing stock nationally, according to landlords.
Emma Cox, sales director at Shawbrook Bank, said: “The true extent of what this legislation could mean for the market has not yet been properly realised.
“Inaction could see a considerable percentage of the private rental sector declared unrentable or unsellable within a matter of years if landlords don’t take important steps now.
“Making changes to improve a property’s energy efficiency rating will help to improve the overall energy efficiency of the UK housing stock and to assist the government in meeting the ambitious net-carbon zero targets set out earlier this year.
“But on a more direct level, making the improvements ahead of the impending 2025 deadline will ensure that properties remain commercially viable for the short and long term for landlords.
“Putting off making necessary changes could leave landlords exposed to extended void periods when their property can’t be rented out while works are being completed.
“Mortgage lenders, and key players in the market, have a big role to play in supporting landlords by helping them to understand the new legislation, the potential impact this could cause and how to take action, if required.
“Our research indicates a clear gap in landlord’s understanding of how the changes will impact them and their current yields.
“As well as these risks to landlords,, renters may also be put in an even worse position as they compete for a smaller number of properties that are rated C or above after the 2025 deadline.”
