This is tough one, because you will never have a room that is perfect in every way. You can find a good general discussion about room acoustics for piano here. It is reproduced from Larry Fine’s Piano Book; the section starts on page 229. If you are already an audiophile then you probably already know about room acoustics. But what you will discover (if you haven’t already done so) is that what you hear on most piano recordings is nothing like what you experience live and in your home.
Actually, addressing the room’s acoustics is something that you should be doing anyway, regardless of whether you plan to do any home recording or not. Homes in Singapore are typically acoustically noisy. If you live in any multi-storey dwelling you probably have a concrete slabs above and below, and walls of either poured concrete or hollow concrete brick. There is also a lot ingress of noise even when the doors and windows are closed. For an idea of what you can do relatively cheaply see Acoustic Treatment for Home Studios. Although it says ‘home studio’ you can apply the same ideas generally for your home to make it acoustically more pleasant to live in.
Incidentally, the wall construction described in the article above is gypsum board with fibreglass filler. It is common in Western countries but rarely seen here. That might change in the future because of the sharply higher price of cement. There have already been calls in the construction industry to look at alternative construction methods that reduce the use of cement.
For more information about room acoustics you can try the Room Acoustics Forum at Audio Asylum.
If you want do fix your room acoustics quickly then you can try these people in Singapore: Alpha Acoustics. The cost can vary from relatively inexpensive to very expensive, depending on how bad your room is and what you want to achieve.