No clear definition of ‘period of ownership’

In 2010 the taxpayers bought land on which there was a house. They demolished that house and built a replacement which was finished in March 2013. They occupied the property until selling it in May 2014. A dispute arose as to the length of time they occupied the property and the correct only or main residence relief (TCGA 1992 s 222 et seq).

In essence was the period of ownership for only or main residence relief purposes the 43 months between the acquisition of the land on which the house was demolished and the sale of the land with the house that was subsequently built? Or was the period of ownership between when the newly developed house was completed and the date of disposal - 15 months?

HMRC considered that because one asset was bought and that asset was sold ‘period of ownership’ should apply to the...