CGT on subdivision that was initially an IP

guys

ok, IP1 (which has been rented for a year) is getting subdivided and built into a duplex next year

result after construction:

rent one side out (unit A), live in the other side (unit

if we chose to sell unit B several years later as our PPOR, would we be completely CGT exempt (with PPOR exemption)?

or will there be a CGT portion to pay because the subdivided land that it was built on was rented out as IP1 for approx 1 year?

i understand that unit A will attract CGT + GST if sold within a year, or just CGT if sold after a year. will CGT be value at point of original purchase (before subdivision) or value at point of subdivision and construction of units A + B?

TIA

roj