Low-Rise Buildings

C8

01 Structural Concepts 02 Prefabricated Walls 03 Assembly 04 Ring Beam 05 Example Building 06 Load-bearing Capacity 07 Details 08 Finishing 09 Fire Protection 10 Construction Concept developed by CREATERRA.

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Structural concepts

» Most loads can be taken up by internal walls made with CLT.

Load-bearing capacity and number of stories depends mainly on structural design decisions.

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Inner walls load-bearing and partial load on 2 facades Partial load on all facades

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All facades are load-bearing

» All facade elements are taking loads from the building

» The internal wooden structure carries approx. half of the load from the floors

» Stiffness of the building can be in part provided by the internal structure

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EcoCocon on two load-bearing facades

» Only the end facades are taking loads

» The internal wooden structure carries most of the load from the floors

» On the long facades the panels carry only themselves

» Stiffness of the building can be provided by the internal structure at least in one direction

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Prefabricated walls

Ready assembled wall

Prefabricated ring beam

» Walls transported to building site pre-assembled

» Ring beam is strong enough for all lifting and handling

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Concept by CREATERRA

Top boards (LVL X) added on site

Preassembled walls element

Prefabricated shutter box added on site

Lignotrend ceiling (or another CLT system) preassembled to 2500 mm or 1875 mm width

Preassembled wall element

On-site Assembly

Concept by CREATERRARing beam detail

Top board (LVL X) added on site

Prefabricated Ring beam

Rothoblaas Xylofon

Gap between LVL X and Lignotrend ceiling

Lignotrend ceilings (with final acoustic surface and 60 min fire protection)

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Ring beam detail

» Ringbeam provides space for shading devices

» Airtight layer is in one level on the outside and protects against the elements

» Standard CLT floors can be used instead of Lignotrend elements

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EcoCocon Straw Walls

Rothoblaas Xylofon (acoustic separation)

STEICO LVL R (prefabricated

ringbeam )

STEICO LVL X (Top beam )

Lignotrend Rippe or Decke (final acoustic

ceiling surface)

Fire protection 60 minAcoustic ceiling

Gravel Gravel

Standard floor layers

Integrated shading (prefabricated)

Pre-installed windows (Passivhaus standard)

EcoCocon Straw Walls

Wood fibre board

(60-100 mm, plastered or clad)

REI 120ef REI 120

Clay plaster / Fermacell

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Sample Floor Plan

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L U S S Y 3 2 6 _ 2 0 . 1 2 . 2 0 1 7

p r o j e t p a r c e l l e n o r dp l a n é t a g e - t y p e

1 : 1 0 0

14.1 m²Chambre

12.0 m²Chambre

17.5 m²Séjour

27.3 m²Cuisine-Séjour

4.4 m²Couloir

5.3 m²S-B

16.6 m²Chambre

5.2 m²Couloir

3.0 m²Reduit

4.7 m²S-B

34.3 m²Cuisine-Séjour

12.0 m²Chambre

14.1 m²Chambre

17.5 m²Séjour

27.0 m²Cuisine-Séjour

4.5 m²Couloir

5.3 m²S-B

13.125 16.225

4.725

2.45 5.95 2.48 10.07 5.90 2.50

3.95

4.75

4.10

5.20

4.75

4.10

5.05

4.10

4.95

1.60

80

5.20

2.40

2.95 7.05

8.40 2.34

3.5 p (80.40 m2)

2.5 p (63.80 m2)

3.5 p (80.40 m2)

3.75 3.40 1.20 1.10 1.30 3.40 3.75 4.725

3.75

3.95

1.40

2.37

51.

403.

751.

30

1.265 1.815 2.41 3.35 8.40

2.50 4.105 2.495 7.00 3.00

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Load-bearing constructions

» Load-bearing facades » Straw wall surface in model 912 m2 -

windows / openings = approx. 775 m2

» 58 000 kg of CO2 sequestered in EcoCocon wall

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Concrete core (alt. CLT)

EcoCocon Straw Walls

Lignotrend Ceilings

CLT

HEB 200 (Concealed in ceiling)

Concept by CREATERRAEcoCocon exterior walls

Integrated lateral reinforcements

Ring beamEcoCocon panels

Balcony construction in

wood

Ring beam

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Inner side: Outter side:

≔q1.1 =qroof 15 ――kNm

≔q1.2 0 ――kNm

≔q2.1 =+―――e2 qroof

⎛⎝ +e1 e2⎞⎠q!oor 20.311 ――kN

m≔q2.2 =―――e1 qroof

⎛⎝ +e1 e2⎞⎠3.689 ――kN

m

≔q3.1 =+―――e2 q2.1

⎛⎝ +e1 e2⎞⎠q!oor 24.317 ――kN

m≔q3.2 =+―――e1 q2.1

⎛⎝ +e1 e2⎞⎠ ―――e2 q2.2

⎛⎝ +e1 e2⎞⎠7.776 ――kN

m

≔q4.1 =+―――e2 q3.1

⎛⎝ +e1 e2⎞⎠q!oor 27.337 ――kN

m≔q4.2 =+―――e1 q3.1

⎛⎝ +e1 e2⎞⎠ ―――e2 q3.2

⎛⎝ +e1 e2⎞⎠11.844 ――kN

m

Physical/mechanical wood properties:

Characteristic bending strength ≔fm.k ⋅36 ――Nmm2

Mean value of modulus of elasticity parallel to the grain ≔E0.mean ⋅10600 ――Nmm2

Characteristic shear strength ≔fv.k ⋅1.1 ――Nmm 2

Characteristic shear strength perpendicular to the grain ≔fc.90.k ⋅4.0 ――Nmm2

Mean value of shear modulus ≔Gmean ⋅500 ――Nmm2

Factors in use:

Partial factor for LVL ≔γM 1.2

Deformation factor ≔kdef 0.6Modi#cation factor for duration of load and moisture content

≔kmod 0.6≔kmod.short 0.9

Depth factor for LVL

h <300mm ≔kh =min⎛⎜⎜⎝ ,⎛⎜⎝―――⋅300 mm

h⎞⎟⎠

0.15

1.2⎞⎟⎟⎠ 1.2

h >300mm

Ring beam optimizes load distribution inside/outside

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LVL X plate calculationGeometric parameters:

Height: ≔h ⋅51 mmWidth: ≔b ⋅400 mmLength: ≔l ⋅800 mmLoad from span: ≔B ⋅6 mExcentricity: ≔e1 ⋅75 mm ≔e2 ⋅230 mm

Space between posts: ≔t ⋅800 mm

Moment of inertia: ≔I =――⋅b h3

12442.17 cm4

Section modulus about the main axis:

≔W =――⋅b h2

6173.4 cm3

Sum of actions: ≔P1 5 kPa ≔P2 3 kPa

Load intensity to the linear meter ≔qroof =⋅⋅P1 B 0.5 15 ――kNm

≔q!oor =⋅⋅P2 B 0.5 9 ――kNm

Fig1. Geometry

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Structural load capacity

A standard wall can take min. 40 kN/m, tested at 70 kN/m.

The exact load-bearing capacity can be calculated by any structural engineer with experience in wood construction.

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Enhancing load-bearing capacity

» Using narrower panels increases the number of posts per m

» Very flexible system as ring beam distributes weight from columns

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This example: XXkN/m

More panels increase load bearing capacity

Concept by CREATERRAShutter box

Prefabricated shutter box

Mounted on site

Concept by CREATERRAOverlapping corner connection (mounted on site)

Corner connection

Airgap between ceiling and LVL

Concept by CREATERRANot visible HEB beam (uninterrupted acoustic surface - only Lignotrend)HEB 200 Uninterrupted surface

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Roof detail

» Same ringbeam can be used for supporting roof

» Loads from the roof can be applied on the outside to improve load distribution

» Roof can be constructed with loadbearing I-beams and no massive wooden ceiling to save costs

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STEICO LVL R (prefabricated

ring beam)

STEICO I-beams (Insulated with blown cellulose )

Lignotrend Block (for roof) (final acoustic ceiling surface)

Accoustic ceiling

Wood fibre board (60-100 mm,

plastered or clad)

Clay plaster/Fermacell

Airtight layer (Sd >10000 m)

Airtight layer (Sd <0.2 m)

TPO or EPDM membrane (+ extensive green roof 60 mm)

EcoCocon Straw Walls

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Foundation detail

» The walls are cantilevered 100 or 150 mm » A strong LVL X board (thickness depends

on structural calculation) ensures a level mounting surface

» Concrete walls are insulated with XPS from 160 to 200 mm

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STEICO LVL X 75 mm

Insulation + Support for cantilevered LVL X every 60 cm (anchored in concrete)

150 mm

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Floor heights

» Height of floors can be adjusted as demanded

» Height of load-bearing Lignotrend ceiling and ring beam depends on structural calculations

» With some extra height, installation of ventilation system can be simplified

» Ventilation can be installed in ceiling or floor (in this case, it is in floor, it adds only 80 mm height for square ducts)

» If higher ceiling in flats (2800 mm), it would be possible to have ducts under ceiling in corridors only

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Wall elements with different levels of finishing

» Panels can be preassembled in a workshop, ideally close to the building site

» The facade surface can also be finished partially to speed up work on site

» Openings can be fitted with windows in advance

» The airtight membrane and weatherproofing can be included in the pre-assembly

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Pre-assembly in a hall Builders: Kontrakting SR | Natural Building Company Oy FI

Express assembly on site Project by Natural Building Company, Finland