Nationally Determined Parameters (Eurocode)

Tekla Structural Designer
Modified: 28 Sep 2022
2024
Tekla Structural Designer

Nationally Determined Parameters (Eurocode)

The Eurocode has differing Nationally Determined Parameters (NDPs) for the Eurocode (Base) and for each of Eurocode (UK), Eurocode (Irish) etc. These are defined in the relevant country's National Annex.

Gamma (γ) factors, psi (Ψ) factors and seismic phi (φ) factors for each National Annex are listed below. The recommended Eurocode values from the Eurocode (Base) are also given.

Gamma (γ) factors

EQU combs
National Annex γGj,sup γGj,inf γQ (fav)
Recommended Eurocode value 1.10 0.9 1.5
UK value 1.10 0.9 1.5
Irish value 1.10 0.9 1.5
Singapore value 1.10 0.9 1.5
Malaysia value 1.10 0.9 1.5
Finland value 1.10kFl 0.9 1.5kFl
Norway value 1.2 0.9 1.5
Sweden value 1.1γd 0.9 1.5γd
STR combs
National Annex γGj,sup γGj,inf γQ (fav)
Recommended Eurocode value 1.10 0.9 1.5
UK value 1.10 0.9 1.5
Irish value 1.10 0.9 1.5
Singapore value 1.10 0.9 1.5
Malaysia value 1.10 0.9 1.5
Finland value 1.10kFl 0.9 1.5kFl
Norway value 1.2 0.9 1.5
Sweden value 1.1γd 0.9 1.5γd
GEO combs
National Annex γGj,sup γGj,inf γQ (fav)
Recommended Eurocode value 1.10 0.9 1.5
UK value 1.10 0.9 1.5
Irish value 1.10 0.9 1.5
Singapore value 1.10 0.9 1.5
Malaysia value 1.10 0.9 1.5
Finland value 1.10kFl 0.9 1.5kFl
Norway value 1.2 0.9 1.5
Sweden value 1.1γd 0.9 1.5γd

The kFl factor used in the Finnish National Annex is set by specifying an appropriate Consequence Class in Settings > Loading > General.

  • CC3 (high consequence for loss of human life or economic social or environmental consequences very great)
  • CC2 (medium consequence for loss of human life or economic social or environmental consequences considerable)
  • CC1 (Low consequence for loss of human life, economic, social or environmental consequences small or negligible)

The γd factor used in the Swedish National Annex is set by specifying an appropriate Reliability Class in Settings > Loading > General.

  • RC3 (major risk of serious personal injury)
  • RC2 (some risk of serious personal injury)
  • RC1 (minor risk of serious personal injury)

Psi (Ψ) factors

  • Ψ0 - Factor for combination value of a variable action.
  • Ψ1 - Factor for frequent value of a variable action.
  • Ψ2 - Factor for quasi-permanent value of a variable action.
UK, Ireland
Recommended Eurocode value UK value Irish value
Action Ψ0 Ψ1 Ψ2 Ψ0 Ψ1 Ψ2 Ψ0 Ψ1 Ψ2
Category A imposed domestic / residential 0.7 0.5 0.3 0.7 0.5 0.3 0.7 0.5 0.3
Category B imposed office 0.7 0.5 0.3 0.7 0.5 0.3 0.7 0.5 0.3
Category C imposed congregation 0.7 0.7 0.6 0.7 0.7 0.6 0.7 0.7 0.6
Category D imposed shopping 0.7 0.7 0.6 0.7 0.7 0.6 0.7 0.7 0.6
Category E imposed storage 1.0 0.9 0.8 1.0 0.9 0.8 1.0 0.9 0.8
Category H imposed roofs 0 0 0 0.7 0 0 0.6 0 0
Snow Loads < 1000m 0.5 0.2 0 0.5 0.2 0 0.5 0.2 0

Snow Loads > 1000m

(2 ≤ sk < 3 kN/m2)

0.7 0.5 0.2 0.5 0.2 0 0.5 0.2 0
Ice Loads 0 0 0 0 0 0 0 0 0
Wind Loads 0.6 0.2 0 0.5 0.2 0 0.6 0.2 0
Thermal Loads 0.6 0.5 0 0.6 0.5 0 0.6 0.5 0
Singapore Malaysia
Recommended Eurocode value Singapore value Malaysia value
Action Ψ0 Ψ1 Ψ2 Ψ0 Ψ1 Ψ2 Ψ0 Ψ1 Ψ2
Category A imposed domestic / residential 0.7 0.5 0.3 0.7 0.5 0.3 0.7 0.5 0.3
Category B imposed office 0.7 0.5 0.3 0.7 0.5 0.3 0.7 0.5 0.3
Category C imposed congregation 0.7 0.7 0.6 0.7 0.7 0.6 0.7 0.7 0.6
Category D imposed shopping 0.7 0.7 0.6 0.7 0.7 0.6 0.7 0.7 0.6
Category E imposed storage 1.0 0.9 0.8 1.0 0.9 0.8 1.0 0.9 0.8
Category H imposed roofs 0 0 0 0.7 0 0 0.7 0 0
Snow Loads < 1000m 0.5 0.2 0 0.5 0.2 0 0.5 0.2 0

Snow Loads > 1000m

(2 ≤ sk < 3 kN/m2)

0.7 0.5 0.2 0.5 0.2 0 0.5 0.2 0
Ice Loads 0 0 0 0 0 0 0 0 0
Wind Loads 0.6 0.2 0 0.5 0.2 0 0.5 0.2 0
Thermal Loads 0.6 0.5 0 0.6 0.5 0 0.6 0.5 0
Nordic Countries
Finnish value Norwegian value Swedish value
Action Ψ0 Ψ1 Ψ2 Ψ0 Ψ1 Ψ2 Ψ0 Ψ1 Ψ2
Category A imposed domestic / residential 0.7 0.5 0.3 0.7 0.5 0.3 0.7 0.5 0.3
Category B imposed office 0.7 0.5 0.3 0.7 0.5 0.3 0.7 0.5 0.3
Category C imposed congregation 0.7 0.7 0.3 0.7 0.7 0.6 0.7 0.7 0.6
Category D imposed shopping 0.7 0.7 0.6 0.7 0.7 0.6 0.7 0.7 0.6
Category E imposed storage 1.0 0.9 0.8 1.0 0.9 0.8 1.0 0.9 0.8
Category H imposed roofs 0 0 0 0 0 0 0 0 0

Snow Loads

(< 1000m)

(1 ≤ sk < 2 kN/m2)

0.7 0.4 0.2 0.7 0.5 0.2 0.6 0.3 0.1

Snow Loads > 1000m

(2 ≤ sk < 3 kN/m2)

0.7 0.5 0.2 0 0 0 0.7 0.4 0.2
Snow Loads ≥ 3kN/m2 0 0 0 0 0 0 0.8 0.6 0.2
Ice Loads 0.7 0.3 0 0 0 0 0 0 0
Wind Loads 0.6 0.2 0 0.6 0.2 0 0.3 0.2 0
Thermal Loads 0.6 0.5 0 0.6 0.5 0 0.6 0.5 0

Seismic phi (φ) factors

An additional phi (φ) factor for Seismic design - from EN 1998-1 Table 4.2 is required for creation of the Seismic Inertia Combination. This is defined with each new imposed or roof imposed loadcase - alongside the psi (Ψ) factors for each of the load types.

UK, Singapore
Cate-gory Default for Storey Factor φ from EN 1998-1 Table 4.2
EC UK Singapore
A - C Roof Imposed Roofs 1.0 1.0 1.0
A - C Imposed = A, B, C Stories with correlated occupancies 0.8 0.8 0.8
A - C Stories independently occupied 0.5 0.5 0.5
D - F Imposed = D, E D-F and Archives 1.0 1.0 1.0
Nordic countries
Cate-gory Default for Storey Factor φ from EN 1998-1 Table 4.2
EC Norwegian Finnish, Swedish*
A - C Roof Imposed Roofs 1.0 1.0 1.0
A - C Imposed = A, B, C Stories with correlated occupancies 0.8 1.0 0.8
A - C Stories independently occupied 0.5 1.0 0.5
D - F Imposed = D, E D-F and Archives 1.0 1.0 1.0
* There are no Finnish or Swedish National Annexes to EN 1998-1 so the recommended Eurocode values are applied.
Was this helpful?
Previous
Next