Since the start of URA’s programme in the 80s, over 6,500 buildings have already been marked for conservation. Conserved buildings include those at the areas of four main districts. Aside from general rules, there are also specific restoration guidelines added to each building and area type.

The historical districts include buildings dating back to the founding of Singapore in 1819, such as Little India, Boat Quay and Chinatown. Most of the buildings are shops. These buildings have unique architectural features from different cultures and races that have inhabited the area. Some guidelines, specifically in the area, include preserving the interior and exterior of the buildings in their original form.

Residential historic district area includes terrace houses on the Emerald Hill and Cairnhill. Most are private homes while others are commercial buildings.

There are some allowances in the guidelines, such as allowing rear extension for those owners who want to have their residential space to be maximised.

For business-centred houses, shopfronts can’t be a clean wall as this could be considered out of character. The façade must keep and restore its decorative features.

The fringe and good class bungalow areas include those in Mountbatten Road., Chatsworth Park, and Nassim Road. Bungalows here are situated in woody areas and have either one or two floors. The architectural design is a combination of local building and Western styles.

The main houses must be kept, according to URA, although extensions can be made by demolishing outhouses. If the building is big enough, developments can be made by dividing the land.

The Secondary settlements category covers older buildings, mostly surrounded by new developments, such as various shophouses in River Valley, Mount Sophia, Joo Chiat and Jalan Besar.

In these areas, the defining features, original structure, and external façade must remain unchanged. Owners can modify the building’s interior to cater their needs.