CSR Hebel Design Approach

There are 2 methods of construction – typical and tie-down. Typical is the most common method of building whilst the tie-down method is required for cyclonic or high wind areas (as determined by an engineer). This guide provides information for both building methods.

Important Note

It is the responsibility of the architectural designer and engineering parties to ensure that the information in the Hebel PowerBlocks Design and Installation Guide is appropriate for the intended application. The recommendations of this guide are formulated along the lines of good building practice, but are not intended to be an exhaustive statement of all relevant data. Hebel  accepts no responsibility for or in connection with the quality of the recommendations or their suitability for any purpose when installed.


The Hebel® PowerBlocks Design and Installation Guide has been created to provide information for detached residential buildings. The design information in this guide has been condensed from the Hebel® Technical Manual and AS3700 Masonry structures. The design basis is AS3700 Masonry structures, Section 12 Simplified design of masonry for small buildings. The footing and slab design is based on AS2870 Residential slabs and footings – Construction.

Refer to Table 6.1 for Building Geometry Limitations.

Design Parameters

The structural design information in this guide is based on the data and assumptions in Table 6.2, 6.3 and 6.4.

Design Sequence

Fig. 6.1 details Hebel® recommendations for how to design a Hebel® PowerBlock home.

Design Flow Chart

Determine the soil classification, terrain category and wind region/loads

Footing type (slab or strip footing)

PowerBlock™ design based on BCA requirements, loadings, wall heights
and lengths (external & internal)

Design the bracing and tie down methods

Determine any additional BCA requirements (thermal, fire and sound ratings)

Complete project documentation (drawings & specification)

Table 6.1: Buiding Geometry Limitations

2 storeys max
Max. height to underside of eaves 6.0m
Max. height to top of roof ridge 8.5m
Max. building width incl. verandah but not eaves 16.0m
Max. building length 5x width
Max. lower storey wall height 3.0m
Max. upper storey wall heigh 2.7m
Max. floor load width on external wall 3.0m (6.0m single span floor)
Max. roof load width on external wall 3.0m (6.0m rafter/truss span)
Max. floor load width on internal wall 6.0m


Where the building geometry is outside the above limitations, the designer must refer to the Hebel® Technical Manual and AS3700 Sections 1-11.

Table 6.2: Design Parameters.

Hebel® PowerBlock™ material properties
Nominal Dry Density 470 kg/m2
Working Density (S.T.) 611 kg/m2
Working Density (L.T.) 500 kg/m2
Characteristic Compressive Strength, f’m 2.25 MPa
Characteristic Flexural Tensile Strength, f’mt 0.20 MPa
Characteristic Shear Strength, f’ms 0.30 MPa
Characteristic Modulus of Elasticity, EST 1125 MPa
Characteristic Modulus of Elasticity, ELT 562 MPa


Table 6.3 Design Parameters – Permanent and Imposed Actions

Permanent Actions (Dead Loads):
Floor – Superimposed 1.00 kPa
Roof – Tile 0.90 kPa
Roof – Sheet 0.40 kPa
Framed Floor/Deck – Timber 0.50 kPa
Framed Deck – Tile 0.50 kPa
Pergola Roof – Tile 0.80 kPa
Pergola Roof – Sheet 0.32 kPa
Hebel® PowerFloor System 0.80 kPa
Hebel® Floor Panel System – 250mm 1.90 kPa
Hebel® PowerBlock Wall – 250mm, 2700mm (H 4.60 kN/m
Hebel® PowerBlock Wall – 150mm, 2700mm (H) 2.76 kN/m
Imposed Actions (Live Loads):
In accordance with AS 1170. 1:2002
Floor – general 1.50 kPa
Deck 2.00 kPa

Table 6.4  Design Parameters – Wind Actions (General wall areas)

Wind Classification(AS4055) Wind Pressure (kPa)
Serviceability, Ws Ultimate, Wu
N1 0.41 0.69
N2 0.41 0.96
N3 0.61 1.50
N4 0.91 2.23
N5 1.33 3.29
N6 1.82 4.44
C1 0.61 2.03
C2 0.91 3.01
C3 1.33 4.44
C4 1.82 5.99

Hebel PowerBlock home

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