About “Public Facility Ratio (公設比)” – Shared Space Allocation

2026-02-09

In Taiwan, when buying or renting a property, you will often come across the term “公設比 ”, or “public facility ratio.” This refers to the proportion of shared spaces in an apartment or condominium building that is allocated to each unit. On our website—as well as in real estate magazines and other property information sites—the room size displayed usually includes this public facility ratio.

Today, we would like to explain what this public facility ratio actually means. It may sound complicated at first, but there is really just one key point to understand:

“The size shown on property listings and the actual usable room size are slightly different, so please keep this in mind!”

If you are short on time or not interested in detailed explanations, remembering this point alone will be enough. Now, let’s take a closer look at what Public Facility Ratio (公設比) really involves.

What Is the Public Facility Ratio?

As mentioned above, the public facility ratio refers to the portion of shared spaces that is allocated to each individual unit. But what exactly counts as “shared space”?

Shared spaces include facilities within the building that are used by all residents, such as:

Swimming pools
Gyms
Meeting rooms
Lounges
Corridors
Elevators
Staircases
Management offices

In short, the more luxurious and well-equipped a building is, the larger the shared space becomes—and therefore, the higher the public facility ratio.

Typical Public Facility Ratios

So how high is this ratio in general? Here is a rough guide based on common property types in Taipei (for studio apartments):

Property Type	Typical Rent Range (TWD)	Public Facility Ratio
Student apartments	10,000 – 15,000	10–15%
Older apartment buildings	13,000 – 18,000	15–20%
Mid-range condos (with simple gym, meeting rooms, etc.)	18,000 – 25,000	Around 25%
Luxury condos (with pool, gym, karaoke, café, spa, etc.)	25,000 – 50,000	Around 30%

For most studio apartments rented by students or single expats, the public facility ratio usually falls between 10% and 30%.

For example, if a student apartment is listed as 33 m² (approximately 355 sq ft) and the public facility ratio is 10%, the actual usable living space would be about 29.7 m² (approximately 320 sq ft). The remaining portion represents the share of common areas—such as hallways and rooftop spaces—allocated to that unit.

Let's look at another example involving a luxury condominium with 100 units.

Example Calculation

Listed size on website:
49.5 m² (approximately 533 sq ft) – studio apartment

Allocation of shared facilities:

Pool: 165 m² ÷ 100 units = 1.65 m² per unit (≈ 17.8 sq ft)
Gym: 99 m² ÷ 100 units = 0.99 m² per unit (≈ 10.7 sq ft)
Meeting room: 66 m² ÷ 100 units = 0.66 m² per unit (≈ 7.1 sq ft)
Spa: 66 m² ÷ 100 units = 0.66 m² per unit (≈ 7.1 sq ft)
Other shared areas (hallways, management office, elevators, etc.):
660 m² ÷ 100 units = 6.6 m² per unit (≈ 71 sq ft)

Actual usable area:
49.5 − 1.65 − 0.99 − 0.66 − 0.66 − 6.6
= 38.94 m² (approximately 419 sq ft)

Public Facility Ratio:
(49.5 − 38.94) ÷ 49.5 = 21.3%

In this case, although the listing shows a room size of 49.5 m² (533 sq ft), the actual living space is only 38.94 m² (419 sq ft). Luxury condominiums often include many shared facilities, which is why the public facility ratio can become relatively high.

Important Points to Remember

If you visit the property in person, you can see the actual room size with your own eyes, so this usually won't be a major problem.

However, if you decide on a property based only on photos or online listings, it is important to keep the public facility ratio in mind. Otherwise, you may find that the room feels smaller than you expected after moving in.