NEN 2580 measurement report: how to measure the usable floor area

NEN 2580 is the standard for the areas and volumes of buildings. The version that applies is NEN 2580:2007, with correction sheet C1:2008. The Besluit bouwwerken leefomgeving (Bbl, the Dutch building regulations) refers to that version for the usable floor area. According to NEN (the Dutch standards institute), you can view the standard free of charge via NEN Connect.

NTA 2581:2011 explains how to draw up a measurement report. There are two kinds: meetcertificaat A and meetcertificaat B.

With meetcertificaat A, you measure on the basis of a detailed check on site. With meetcertificaat B, you measure from drawings.

A core group at NEN is working on improving the standard. Until there is a new version, the 2007 version continues to apply.

The Waarderingskamer (the Dutch body that supervises WOZ property valuations) publishes the Meetinstructie gebruiksoppervlakte woningen, version July 2019. It is meant for estate agents and valuers who measure for a sale, letting or valuation. Municipalities use it to measure for the BAG (the Dutch national register of addresses and buildings) and the WOZ (the municipal property valuation).

Besides this instruction, there is a Meetinstructie bruto inhoud woningen (for gross volume), with a survey form. For the usable floor area, there are a survey form and a measurement schedule.

The model taxatierapport woonruimte (the standard valuation report for homes, version January 2024) calls it the industry-wide Meetinstructie, BBMI for short. A uniform measurement schedule belongs with it as an annex. The report also asks who measured.

The Meetinstructie builds on NEN 2580. This is what you need to know:

• The Meetinstructie splits into living area and other indoor space; NEN 2580 does not
• The Meetinstructie measures including load-bearing internal walls; NEN 2580 excludes them
• Where the instruction and its FAQs give no clear answer, NEN 2580 applies

NEN 2580 has more than one kind of floor area. The best known are the bruto vloeroppervlakte (BVO, gross floor area) and the gebruiksoppervlakte (GO, usable floor area).

You measure the GO at floor level, between the walls around a space or group of spaces. You measure the BVO along the outside of those walls. So the walls count in the BVO.

According to NEN, the difference between BVO and GO can be as much as 30%. So always state in your measurement report which area you mean.

The BAG and the Bbl use the GO. For the environmental performance (MPG) of a new building, by contrast, you calculate per m² of BVO.

When a home goes on the market, you split the GO into four categories as far as possible. Living area and other indoor space together make up the indoor usable floor area:

• Living area
• Other indoor space, such as a basement or a low loft
• External storage space
• Building-related outdoor space, such as a balcony, carport, veranda or roof terrace

A space counts as other indoor space if its highest point is between 1.5 and 2.0 m. A higher space with less than 4 m² of contiguous area above 2.0 m can also fall into this category.

The same applies if a space is structurally only suitable as storage. Think of a basement, bicycle store or garage. Or a storage loft, for example without a fixed staircase or with less than 0.5 m² of window.

If in doubt, the space counts as living area. You do not count these parts at all:

• Floor area with a clear height below 1.5 m, except under a staircase
• Spaces that are not accessible
• A stairwell opening or void of 4 m² or more
• A shaft or free-standing structure of 0.5 m² or more
• A lift shaft

The BAG records the total indoor usable floor area for each home. That corresponds to living area plus other indoor space, according to NEN 2580.

For the WOZ, the Meetinstructie ensures that all homes are measured in the same way. If the area in the BAG is wrong, report it via the BAG viewer. Such a report is not an objection to the WOZ value. You can object within 6 weeks of the date of the WOZ decision (WOZ-beschikking).

For the points count of a rented home, the Huurcommissie (the Dutch Rent Tribunal) measures differently. It measures internally, from wall to wall at 1.50 m height, including built-in cupboards. So a measurement according to NEN 2580 is not automatically the area for the points.

The EP adviser (who makes the energy label) also measures: the usable floor area of the thermal zone, according to the Meetinstructie.

Three measuring rules exist side by side: NEN 2580, the Meetinstructie and the measurement for the points count. They treat walls and spaces differently.

The Meetinstructie exists to make measuring simpler and more consistent. So follow it exactly, and note how you measured.

So watch out for these points:

• State who measured, and whether you measured on site or from drawings
• State whether a figure is the BVO or the GO: the difference can be 30%
• Measure the height: 1.5 m and 2.0 m determine whether and how a space counts
• Watch for load-bearing internal walls: the Meetinstructie includes them, NEN 2580 does not
• Compare with the BAG: it may differ because of its own rules, for example for an integral garage
• For the points count of a rented home, use the Huurcommissie's measuring rules

The NEN 2580 measurement report is listed in Keursnel as coming soon. You cannot make a measurement or measurement report in it now. There is no date, and what it will include has not been decided.

However, for a building inspection, Keursnel retrieves data from the BAG. The usable floor area from the BAG then appears as a characteristic in the inspection. For a building with one home, the volume from the 3D BAG is added too. That is data from the BAG, not a measurement according to NEN 2580.

This site has a free calculator for the usable floor area. It does not replace a measurement report.

Would you like to make measurement reports in Keursnel later? Let us know via the contact page. The building inspection already includes:

• Property data from the BAG, with a notification to check it
• Photos with markup, such as arrows, frames and numbered points
• Team and roles, and working with colleagues in one inspection at the same time
• Built to work without internet: your work waits, encrypted, on your device
• A report in your firm's house style (paid plan)
• A report with a checksum, to share with the client via a link