HDB counts rooms, not bedrooms, and it counts the living room among them. So a 4-room flat has three bedrooms and a living room, and a 3-room flat has two bedrooms. It trips up almost everyone at first.
The types you will meet
- 2-room: one bedroom, around 45 sqm. Mostly newer Flexi flats, sold on shorter leases to seniors.
- 3-room: two bedrooms, 60 to 70 sqm, common in the older mature estates.
- 4-room: three bedrooms, around 90 sqm. The most traded size by a wide margin, and the one people compare towns with.
- 5-room: three bedrooms plus a study or a larger living room, around 110 sqm.
- Executive: the largest, 130 sqm and up, often with a loft. Built mainly in the 1980s and 1990s, so their leases are well advanced.
Why the model matters
Within one flat type the sets the layout and the size. Model A and Improved are the everyday ones. Maisonettes run over two floors and are no longer built, which is exactly why they sell at a premium. DBSS flats were built by private developers to HDB rules and look more like condominiums. Premium Apartment flats came with the floors and fittings already done.
Two 4-room flats in the same town can differ by 20 square metres, and by a good deal of money, on the strength of the model alone. That is why every figure on this site is reported per block and flat type rather than as a town average, and why each transaction lists the model it was.