Plot ratio

What is the plot ratio?

When you’re looking for land for your future dream home, it has to meet several requirements. Location, green space, neighbourhood, tax liability – all of this is important in your decision. Even if you’re buying a plot of land that’s already been built on, you can still pursue a conversion or an extension. But don’t forget to take this particular figure into consideration before making the purchase. We’re talking about the plot ratio.

The plot ratio (also referred to as the floor area ratio in some cantons and calculated slightly differently) describes the exact dimensions of an approved construction for a particular plot. The higher the number, the larger the structure that can be built. Local construction plans specify which buildings are allowed to be built on which plots. This takes into consideration not only the number of floors but also the distances from the boundaries of the plots and even the permitted use classes.

Plot ratio or floor area ratio: significance

The plot ratio is the area of the plot in relation to the gross floor area (living space). The higher the number, the larger the building is allowed to be, and the more flexibility you have as the building owner – and thus the more valuable the plot is.

In some cantons, the floor area ratio is used instead. This number takes into account all of the areas of a building, whereas the plot ratio excludes non-inhabitable spaces (e.g. garage, basement, open balcony).

Another important dimension in this context is the allowable land area. This corresponds to the size of the plot minus all recreational areas, green spaces and access to necessary paths.

Where can I find or how can I determine the plot ratio?

The plot ratio can be found in the zoning plan and in the building regulations of the local municipal or city administration. They are often also available on the internet.

Queries should still be addressed to the responsible building authorities before any construction projects. Bear in mind that while any change to the plot ratio is generally not an option, local zoning plans are always being amended. There can even be changes when you buy an older property if the documents are not up to date. For this reason, it’s better to ask the building authorities as many questions as possible.