GFA – how is it calculated? What area can you build on your plot?

When we buy a plot or plan the construction of a new building, one of the most important questions is how many square meters we can actually build on it. This is where the concept of GFA – Gross Floor Area.

GFA is a metric that is essential for real estate investments, the purchase of regulated land properties (RLP), the design of residential buildings, and determining the potential for construction.

But what exactly does GFA mean? How is it calculated? What is the difference between GFA, built-up area, and net living area? And how can we find out how many square meters we can build on a specific plot?

In this article by KANTORA 056, we will explore the basic concepts with practical examples.

1. What is GFA?

GFA stands for "Gross Floor Area". According to § 5, item 18 of the Additional Provisions of the Spatial Planning Act (SPA), gross floor area is the sum of the built-up areas of all above-ground floors of the main and supplementary buildings.

GFA also includes the built-up areas in the attic space of the buildings. The built-up area of the above-ground floors includes the entire area of balconies, loggias, and terraces.

In simpler terms, GFA shows the total area of the above-ground levels of the building, calculated according to applicable regulatory rules.

This metric is particularly important when assessing the possibility of construction on a given plot.

2. How is GFA calculated?

The calculation of gross floor area is done by summing the built-up areas of all above-ground floors that are included in the metric.

The formula is:

GFA = Area of first floor + Area of second floor + Area of third floor + ...

For example, if a building has three above-ground floors with the following areas:

• First floor – 120 sq.m.
• Second floor – 120 sq.m.
• Third floor – 100 sq.m.

The total gross floor area is:

120 + 120 + 100 = 340 sq.m. GFA

It is important to note that this is a simplified example. In actual calculations, all elements included in the built-up area by the regulatory framework must be taken into account.

3. What is the difference between GFA and built-up area?

These are two concepts that are often confused, especially by people planning construction for the first time.

Built-up area shows the area occupied by the building on the land, determined by the external outlines according to the SPA.

Gross Floor Area (GFA) represents the sum of the built-up areas of all above-ground floors.

For example:

If we build a house with an area of 120 sq.m. on each of three above-ground floors, we will have:

• Built-up area – 120 sq.m.
• GFA – 360 sq.m.

This means that the building occupies 120 sq.m. of the land, but its total gross floor area is 360 sq.m.
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4. What is the difference between GFA and net living area?

This is one of the most frequently asked questions when purchasing an apartment.

GFA is not equivalent to the net area of the dwelling.

When determining the gross floor area, the areas are accounted for according to the regulatory definition, including balconies, loggias, and terraces, as well as other areas of the above-ground floors.

Net living area is a different metric and should not be automatically assumed to be equal to GFA.

When purchasing a property, it is important to check what type of area is specified in the offer and in the ownership documents.

5. How does the building intensity coefficient (BIC) determine the possible GFA of a plot?

BIC is the coefficient of building intensity. It shows the ratio between the gross floor area and the area of the regulated land property.

It is through this that we can make a preliminary estimate of the potential GFA of a given plot.

The formula is:

Maximum GFA = Area of the plot × BIC

Let’s consider a specific example.

We have a plot with an area of 500 sq.m. and a permissible BIC of 1.5.

The calculation is:

500 × 1.5 = 750 sq.m.

This means that under the specified conditions, the maximum GFA according to the BIC is 750 sq.m.

However, this does not automatically mean that we can build a building with three floors of 250 sq.m. each.

Other planning indicators must also be taken into account, including building density, height, setbacks, building lines, and the specific conditions of the applicable development plan.

6. Examples of GFA calculation with different BICs

Let’s look at a few example plots to see how the possible gross floor area changes.

Plot of 400 sq.m. at BIC 1.5:

400 × 1.5 = 600 sq.m. GFA.

Plot of 600 sq.m. at BIC 2:

600 × 2 = 1200 sq.m. GFA.

Plot of 800 sq.m. at BIC 1.2:

800 × 1.2 = 960 sq.m. GFA.

These examples illustrate why BIC is so important when evaluating an investment property.

Two plots with the same area can have completely different construction potential depending on the permissible indicators.

7. Are balconies, terraces, and attic space included in GFA?

Yes. The Spatial Planning Act explicitly states that the entire area of balconies, loggias, and terraces is included in the built-up area of the above-ground floors.

The gross floor area also includes the built-up areas in the attic space of the buildings.

This is an important detail when preparing investment projects and preliminary calculations for construction.

For a specific project, the architect must determine which areas are included in GFA according to the intended use and regulatory requirements.
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8. Is the basement included in GFA?

Here, an important distinction must be made.

According to the general definition of GFA in § 5, item 18 of the SPA, the metric covers the above-ground floors of the main and supplementary buildings.

Therefore, underground areas are not automatically added to GFA according to this definition.

However, different rules for accounting areas may apply in specific investment and other regulatory calculations. Therefore, it is necessary to check the intended use of the premises and the applicable regulatory act.

9. How to find out what GFA we can build on a specific plot in Burgas?

If you have a plot in Burgas or are planning to purchase a property for investment purposes, it is not enough to know only its area.

You need to check:

• What is the purpose of the property?
• In which zoning area does it fall?
• What BIC is permissible?
• What is the maximum building density?
• What is the permissible height?
• What are the setbacks from neighboring properties?
• Are there any restrictions related to the current development plan?

A particularly useful document is The Design Visa, when it is necessary and applicable to the specific case. It contains information about the conditions and indicators for designing the respective property.

Before purchasing a plot, it is advisable to check the planning indicators to determine its actual construction potential.

10. Why is GFA so important when purchasing a plot?

In real estate investments, the area of the plot is not the only factor determining its value.

It is also important what kind of building can be realized on it.

For example, two plots of 600 sq.m. can have different investment potential if one has a permissible BIC of 1.0, while the other has a BIC of 2.0.

In the first case, the estimated GFA according to BIC is 600 sq.m., while in the second it is 1200 sq.m.

This difference can be significant for an investor planning to build a residential building.

Therefore, when choosing a plot, it is important to analyze not only the location and price but also the urban planning indicators.

11. Frequently Asked Questions about GFA

What does GFA mean?

GFA stands for Gross Floor Area. It represents the sum of the built-up areas of all above-ground floors of the main and supplementary buildings.

How is GFA calculated?

GFA is calculated by summing the built-up areas of all above-ground floors, including applicable areas of balconies, loggias, terraces, and attic spaces.

How is GFA calculated according to BIC?

The area of the regulated land property is multiplied by the permissible BIC. The resulting figure shows the maximum GFA according to this indicator, provided that the other planning requirements are also met.

Are balconies included in GFA?

Yes. According to the SPA, the entire area of balconies, loggias, and terraces is included in the built-up area of the above-ground floors.

Is the underground garage included in GFA?

Underground areas are not automatically included in GFA according to the general definition of the SPA. Their accounting depends on the specific regulatory requirement for which the calculation is made.

Who determines the GFA of a building?

GFA is determined during the development of the investment project by the respective designers, following the definitions and requirements of the applicable regulatory framework.

Conclusion

GFA is one of the most important indicators when planning construction and assessing the investment potential of a real estate property.

Understanding the relationship between GFA, BIC, building density, and plot area helps owners and investors make more informed decisions.

Before purchasing a plot or starting an investment project, carefully check the planning indicators and construction possibilities.

KANTORA 056 – Burgas

If you are looking for a plot for construction or want to invest in real estate in Burgas, contact the KANTORA 056 team. A proper preliminary assessment of a property is an important step towards a successful investment.