thanks for you replies.

Am i correct in saying if acquire an ownership interest in the new property within 6 months period(initial selling and moving) it will receive main residence exemption?

Do i then have 6 months to sell the new property before the exemption expires or do i just calculate via apportionment?

im confused about the apportionment calculation..Since the dwelling was never rented or there was no dwelling present. So do i just calculate from the time i move in?

For example : June 30 1994 purchase of land 140000, sell on July 1 2012(6,576 days) capital gain is 350,000, the occupancy time is 183 days from Jan 1 2012.

350,000 X 6576 – 183 / 6,576 =340,260.03

have i calculated that correctly.??