The Department for Work and Pensions has overturned a tribunal’s decision to exempt two brothers from the bedroom tax due to room size.

The landmark ruling is a blow to anyone hoping to challenge the bedroom tax solely by arguing that a room is too small to be considered a bedroom because of overcrowding definitions in the relevant Housing Acts in Scotland and England.

The upper tribunal ruling, which is binding on all first-tier tribunals in Britain, found there was no relevant link between the overcrowding definitions in the Housing Act and bedroom tax regulations. The Housing Acts state that a room between 50 and 70 square feet is only sufficient for a child under the age of 10.

Last year James and David Nelson successfully appealed to a first-tier tribunal against Fife Council’s decision to reduce their housing benefit. They argued that under the Housing Act (Scotland) 1987, their third room was too small to be considered a bedroom and they therefore should not be subject to the bedroom tax.

The DWP appealed this judgement and the upper tribunal on 26 November overturned the decision.

Giles Peaker, partner at Anthony Gold solicitors told Inside Housing that room size has been the most common grounds of appeal against the bedroom tax.

Mr Peaker, writing in his blog, said the upper tribunal ruling means ‘any appeal based solely on the Housing Act room size figures will not succeed’. However, Mr Peaker said room size could still be relevant if mentioned as one of a number of factors, along with lighting, windows, ventilation and height, that may indicate a room is not a bedroom.

The government has never defined the term ‘bedroom’ for the purposes of the bedroom tax.