If you managed to purchase a new HDB flat, especially a Build-To-Order (BTO) flat, you would have made your first pot of gold. This is because new HDB flats are heavily subsidized and after meeting the Minimum Occupation Period, they can be sold to the open market for substantial profits. So congratulations and lucky you! But there are a few frightening HDB rules that Singaporeans must know. Failing to do so may hamper your financial plan or even worse, damage your wealth.