Plans to build an outbuilding containing a gym and games room in the back garden of a £4 million house have been decisively dismissed following an appeal.

The appellant had hoped to knock down the existing outbuilding at their home in Newlands Avenue, Radlett - which currently contains a gym complete with cycling machine, treadmill, pool table and table football - and replace it with a new single-storey building containing a larger gym and games room.

Under the submitted plans, the larger gym was designed to house two treadmills, a spinning bike, a press bench, three exercise mats and one other piece of equipment not specified in the plans.

However Hertsmere Borough Council rejected the plans, and so the owner of the property appealed to the planning inspectorate in an attempt to overturn the decision.

He argued that because the outbuilding would be used by the entire family, the existing gym was of insufficient size to safely accommodate equipment reasonably required for family use.

But the appeal was dismissed by government planning inspector Stephen Brown, who said: “There is little justification provided as to why it is reasonably required to provide gym facilities for some seven or eight activities to go on simultaneously, as well as having a games room dedicated to pool playing.

“This is particularly so given that the existing gym – which has an area comparable with the proposed gym, when the service rooms are excluded – clearly provides for both exercise equipment as well as a pool table.”