Over at the Pre-War section of the Tiong Bahru Estate, it is quite common to see unauthorised renovations amongst the residents there.
Before purchasing a Pre-War Tiong Bahru flat, it would be prudent to ask the owner or the seller's agent if there are any unauthorised renovations within the flat.
Some obvious ones that are easily spotted would be the location of the MAIN DOORS for ground floor units. The original Pre-War flats does not have any main door facing the corridor walkways except for a few rare units who has such privileges.
Most main door should be located within the stairways in the buildings. If it is located along the corridor walkway, the owner would be required to shift the door back to its original position before the transaction could be completed. Many a times, this has caused a lot of unnecessary argument over who should pay for the relocation of door and whether or not the owner has to reinstate back the door after the inspection is done.
The other obvious NON APPROVED renovations would be the hacking down of walls in the AIR WELL area. This is especially common amongst the ground floor owners. When these owner sells, they are also required to put back the wall and remove whatever shelters they might have put up to prevent rain from coming in.
Illegal gates are also another thing to look out for. Most gates should be right in front of the main door. But the building design here at Tiong Bahru basically allows owners to cordon off certain segment of the stairs and use it as a personal space. These owners could get away with no complaints because such units are located on the top most floor. No one uses the stairways except the owners themselves. Anyway, most new owners will promptly reinstall these illegal gates. People are basically territorial creatures.
I can only speculate on why there are so many unauthorised renovations around here. It could be because these flats are really old. The enforcement was probably very lax in the past. Monkey see monkey do. If everyone else is doing it, it is probably right. So the owners just keep trying to test the limits. Some unfortunately owners were not even aware that the flat they purchased many years ago contained unauthorised renovations and gets a rude shock only when they try to sell the property.
There was also a period in time where these flats were actually slated for demolition. It may be also be part of the reason why some officials closed one eye when inspecting the place. They never expect the demolition plan to change but it did and the place actually got gazetted as a conservation area in 2003!
Now URA and HDB are managing this area and there are some grey area where both of them cannot decide on who should be responsible. You will definitely have a lot of fun interacting with them when you are renovating your abode.