Readers’ forum: Main residence development

My husband and wife clients have been resident in their jointly owned private property for more than 25 years. Recently they obtained outline planning permission to build four private dwellings on their land. This will involve the demolition of their home which is located in grounds of less than one acre. A development company has offered my clients about £1.5m although this has not yet been accepted. The initial plan would be that the clients will vacate their house when the sale is completed. They would not be involved in the development of the new houses and their interest in the property and any connection with it will cease at the point of sale.

The question of capital gains tax has to be considered and because the sum involved is much larger than usual for me I am wondering whether the only or main residence exemption will...