hdb floor plan room 5i flat singapore 3ng 4a ea sqm types 4s improved flats simplified teoalida sample 1984 block
hdb 5i teoalida improved sqm balcony evolution 2010s
sqm hdb 120 5i teoalida bungalow 120sqm corridor end 1930s
floor hdb condo flats floorplan drafting teoalida symbol