Regulations have now been laid in Parliament to require private rental properties to be brought up to a minimum level of energy efficiency from April 1, 2018.
It means the clock is now ticking for such homes to achieve an EPC rating of at least E.
Energy and Climate Change minister Ed Davey (Lib Dem) said that these “new tough rules for the private rented sector” would benefit around a million tenants.
The changes mean that F and G rated properties will become illegal to let out.
But Spark, the specialist energy provider to the private rented sector, warned that the requirement could prove a disaster.
The firm estimates that one in ten private rental properties will become illegal for rental purposes in the next three years, and that energy efficiency upgrades cost on average £9,000 per property – more than a year’s average rent.
Chris Gauld, CEO at Spark, said: “This legislation has the potential to burst the current buy-to-let boom.
“If landlords cannot afford these upgrade costs, which will run into thousands of pounds, then their rental property will be unlettable and void periods would inevitably follow.
“This could spell disaster for landlords and that is why we are urging them to check the EPC rating of every property in their portfolio and plan ahead for these added costs.”
He said it was important for the changes to be communicated early to landlords.