Property development as only source of income.

Yes, you would be responsible for capital gains taxes on these types of properties and potentially ordinary income taxes. That depends on whether the proerty development is considered a business or an investment. The more of these transactions you do in a year the more likely it will be treated as a business and thus taxes at ordinary rates. Before you go too far I would suggest you talk to a qualified CPA in your area who is familiar with these types of transactions. As an aside, technically items such as a car and television are capital items and would qualify for capital gains tax if you sold them at a gain. Losses for these items are nondeductible.