I think I may have a few questions coming up to help us decide whether to build or sell if we get our DA through. I'm trying to work the figures for build or sell, but don't know how to do it. We have two blocks together, each worth probably $900K. We were recently offered $1.8M for them, so let's say $900K each is about right. Our plan is to keep each house on its own 375sqm (thereabouts) block and create a middle block of about 1000sqm. Current UCV for the 900sqm blocks is about $550K each. I'm guessing UCV for the two newly created small blocks of 375sqm may be about $400K each. Guessing the 1000sqm block in the middle is likely to come in at about $600K. If we decide to sell one of the houses, we paid for a 900 sqm block and a house. We would be selling the same house on a block less than half the size. How (and who) works out what we would pay in capital gains tax when we are talking apples and oranges. What we are selling is very different to what it started as. We are selling something that is less than half of what we paid for.