Norwegian Foundation Depth & Width: Why TEK17 Sets No Fixed Number

The requirement

TEK17 sets no fixed footing depth, width, concrete grade or rebar cover. There is no frost-line rule and no metre figure in the code. §10-2(3) hands all of it to design under the Eurocode standards. Depth and width come from your site’s ground and loads, not from the regulation.

Foundation design sits under TEK17 Chapter 10, the structural safety chapter, at §10-2. That clause covers the basic requirements for a structure’s mechanical resistance and stability, including ground conditions. It routes them to the Eurocode series with the Norwegian National Annexes. That means NS-EN 1990 for the basis of design, plus NS-EN 1991 through NS-EN 1999. For footings and ground, the key one is NS-EN 1997, Eurocode 7. It covers the geotechnical design. No metre figure is printed in TEK17 or its official guidance, the veiledning.

A frost-depth figure sometimes gets quoted on site. It comes from SINTEF Byggforsk’s Byggforskserien. That series is respected trade guidance, but it is paywalled and it is not law. It is not part of TEK17. So no quoted number is safe to treat as a code minimum. Frost depth depends on your site and your region. TEK17 §10-2 defers it to the geotechnical design under Eurocode 7.

TEK17 §10-2 · Eurocode deferral

1 footing
2 ground

Width has no fixed table either. Some codes print a width table by soil type and load. TEK17 does not. Strip-footing width comes out of Eurocode 7 design. It rests on your soil’s bearing capacity against the building’s real loads. You work it out per project.

The concrete and the cover. The concrete grade is not in TEK17 either. That job goes to Eurocode 2, NS-EN 1992. It sets the strength class by exposure and by the structural design. Rebar cover follows the same route. It comes from the exposure-class cover tables in NS-EN 1992-1-1, not from one national figure.

Work it out on site

TEK17 gives you no depth or width to plug into a volume sum. Those two figures come off your site’s ground report and your Eurocode 7 design. Once you have both, the concrete volume is plain maths. The calculator does that part. Say your foundation is designed at:

Total length of trench: 24 m.
Footing width: 0.50 m. Example only. Read yours off your project’s Eurocode 7 geotechnical design.
Footing depth: 1.0 m. Example only. It is set by your site’s ground and your frost protection design.

Volume = length × width × depth:

24 × 0.50 × 1.0 = 12.0 m³

So you’d order about 12.0 cubic metres. Then add a bit for spillage and an uneven trench. Most builders tack on 5 to 10 per cent. Swap in your own depth and width once your design is settled. The calculator does the sum.

Do it in 5 seconds

Part of the Norwegian Building Regulations hub. One national regulation, with the veiledning and calculators that solve it.
Setting out the stairs on the same build? See Norwegian stair & guard rules.

Sources

TEK17 §10-2 (Konstruksjonssikkerhet) — the deferral to the Eurocode design series for foundation depth, width, concrete grade and rebar cover. Read it at dibk.no.

Read this first. These figures reflect TEK17 as amended, in force since 1 July 2017. Foundation design in Norway runs through Eurocode 7 (NS-EN 1997) for ground/depth/width and Eurocode 2 (NS-EN 1992) for concrete and cover, with Norwegian National Annexes applying — this is TEK17’s own deliberate deferral, not a gap in research, and no single depth or width figure should be presented as a national minimum. Get your ground checked by a proper site investigation before you dig.

Frequently asked questions

Is there a minimum foundation depth in Norway?

No, not in TEK17 itself. §10-2(3) hands foundation and ground design to the Eurocode standards, mainly NS-EN 1997, Eurocode 7. No metre figure is printed in the regulation. A frost-depth figure sometimes gets quoted from SINTEF Byggforsk's Byggforskserien. That guidance is paywalled and not law. Treat no quoted number as a code minimum.

How wide does a strip footing need to be?

TEK17 sets no fixed width table. Width is a design outcome under Eurocode 7, NS-EN 1997. It comes from your soil's bearing capacity and the building's loads. There is no number to read off the regulation.

What concrete grade goes in a Norwegian footing?

TEK17 does not name a grade. Concrete design goes to Eurocode 2, NS-EN 1992. That standard sets the strength class by exposure and by the structural design. No grade is fixed in TEK17 itself.

What's the rebar cover on a reinforced footing?

Not in TEK17 either. Cover comes from the exposure-class cover tables in Eurocode 2, NS-EN 1992-1-1. Those tables work off your ground conditions and design life. There is no single national number.

Why doesn't TEK17 just print the numbers?

Because §10-2(3) is a deliberate choice, not a gap. It routes the basic requirements for a structure's mechanical resistance and stability, including ground conditions, straight to the Eurocode standards with Norwegian National Annexes. That ties the design to your real site and loads, not one fixed national figure.