Creating new units in strata plan?

Is it possible to create new units in a strata plan by developing/building additional units in the backyard? – STCA! Our yard is quite large and possibly could hold a small granny flat of 1-2 storeys. I imagine this could be of benefit to the OC, that 75% would have to be in agreement and that some compensatory payment again might be in line. We live on the top floor, love our location but our ageing knees mean we need to start thinking 5-10 years down the line to when we can’t climb 3 flights. The yard would need re-landscaping and improvement, just wondering if this is at all possible?