CGT and building plot

I have been granted planning permission to build a second seperate dwelling house in my garden. I suspect (possibly incorrectly) if i either sell it either as a building plot or a fully developed house i will have to pay a large chunk of CGT. However what if i sell my current house and move into the newly built one only to move from there in a few years time, would this avoid incurring CGT on the sale of the newly built house ?