Communities Secretary Eric Pickles faces a potential judicial review over a statement last year in which he scrapped the “conservatory tax”, ruling out consequential improvements plans for small buildings.
The Association for the Conservation of Energy said in a blog that it has taken legal advice and is “confident” that Mr Pickles was vulnerable to review, which applies when ministers are known to have acted irrationally, disregarding facts uncovered by a consultation that they initiated.
An ACE director described the decision as “perverse” and “appalling”. The body says that the application for judicial review will proceed unless Mr Pickles withdraws his statement by February 11.
Mr Pickles issued a public consultation last January proposing that around a tenth of the cost of extensions and garage conversions be spent on improving energy efficiency.
Such requirements are already in place for larger buildings, but do not apply to those below 1000 sq mt.
The ACE says consequential improvements were deemed likely to provide £11bn of economic benefit, as well as a 130m tonne reduction in CO2.
It also said some 2.2m fewer households were likely to take up Green Deal packages without the changes to consequential improvements.
A YouGov opinion poll in May found that the public were almost 2 to 1 in favour of extensions triggering further energy improvements.
ACE said Mr Pickles, in justifying his decision not to go ahead with the proposals, used report summaries that “seriously distort the research evidence” and “misrepresent the conclusions reached”.
ACE Director Andrew Warren said: “There is no explanation whatsoever for Mr. Pickles’ change of heart. Apart from his formal statement on December 13, we cannot tell why he has decided to reject a scheme, which, less than a year earlier, he was recommending so strongly.”
“His decision is too perverse to remain unchallenged. It is, put bluntly, appalling governance.”