Aster Solutions - Sustainable Construction Methods by optimizing Natural and Renewable Resources

STRAW BALE HOUSES

Maurizio Macrì e Stefania Mancuso Architetti

Ing. Claudio Di Taddeo - Aster s.r.l. Società di ingegneria1STRAW BALE HOUSES

Master in Interior Design

Prof. Arch. Filippo Taidelli

“Sustainable approach can bring to a

creative solution”

Why Straw bale houses?Reason #1 Energy Efficiency.• A well built straw bale home can save you up to 75% on heating and cooling costs.

Reason #2 Sound Proofing. • Straw bale walls provide excellent sound insulation and are superior wall systems for home owners looking to block

out the sounds of traffic or airplanes in urban environments.

Reason # 3 Fire resistance. • Straw bale homes have roughly three times the fire resistance of conventional homes. Dense bales mean limited

oxygen which in turn means no flames. (REI90)

Reason # 4 Environmental responsibility. • Building with straw helps the planet in many ways. For example, straw is a waste product that is either burned or

composted in standing water. By using the straw instead of eliminating it, we reduce either air pollution or water consumption, both of which impact the environment in general.

Reason #5 Natural Materials

• The use of straw as insulation means that the standard insulation materials are removed from the home. Standard fiberglass insulation has formaldehyde in it, a known carcinogen. Bale walls also eliminate the use of plywood in the walls. Plywood contains unhealthy glues that can off-gas into the house over time. Straw =0.04-0.06 W/mK

Reason #6 Fast construction

• Straw bale house can grow up very quickly

2Maurizio Macrì e Stefania Mancuso Architetti

Ing. Claudio Di Taddeo - Aster s.r.l. Società di ingegneriaSTRAW BALE HOUSES

The beginning…





The beginning…



The beginning…



The beginning…

Recent straw bale house…












Construction Methods



DIFFERENT CONSTRUCTION METHODS

• LOADBEARING

• PRECAST

• INFILL AND TIMBER FRAME

• LIGHT WEIGHT FRAME AND LOADBEARING

• HYBRID

Load bearing walls



NEBRASKA-STYLE WALL

• The bales themselves take the weight of the roof -

there is no other structural framework

• They are placed together like giant building blocks,

pinned to the foundations and to each other with

coppiced hazel, and have a wooden roof plate on

top

• Openings must be as small as possible



Load bearing walls



VALLELUNGA (BZ)

ITALY

Bed&Breakfast woth

Load Bearing

Walls(jumbo bales) - 3

floors

Load bearing walls



Load bearing walls

Load bearing walls





A new building system from Austria:

• Austrian prefabrication system that combines the traditional

building techniques to the straw material.

• Prefab straw walls are assembled in the factory and made of

wood with vertical portals placed at fixed distance and fixed

to sleepers diagonals.

• The panels can be supplied with straw or just with the wood

structure, so to allow the manufacturer to complete the work

Prefab straw bale walls



Prefab straw bale walls

Precast straw bale walls



AMSTERDAM

HOLLAND

Edificio di 5 piani

fuori terra

realizzato in 6

giorni



takes the advantage of the insulating capacity of the straw to

make courtain insulation.

This system is very economical but has the negative aspect of

a strong thickening of the perimetral wall.The new straw courtain must be firmly attached to the existing

building in order to avoid convective phenomena.

Straw bale courtains

Straw bale courtains



GERMANY

ITALY

The structure of a strawbale house:

DIFFERENT METHODS OF BUILDING

• LOADBEARING

• LIGHT WEIGHT FRAME AND LOADBEARING

• INFILL AND TIMBER FRAME

• HYBRID



Italian Building CodeThe only structural system admitted according to the

2008 Italian Building code is:

TIMBER FRAME



Light frame

PIONEERED BY BARBARA JONES

• It uses a timber framework that is so light-weight

that it cannot stand up alone.

• It requires temporary bracing to give it stability until

the straw is in place.

• The straw is an essential part of the structural

integrity of the building and it works together with

the timber to carry the load of floors and roof.



Post and beam/timber frame• In this method, the weight of the roof is carried by a

wood, concrete framework, and the bales are

simply infill insulation blocks between the posts.





Post and beam/timber frame



SCIOLZE (TURIN)

ITALY








Timber frame elementsFOUNDATIONS: T-SHAPED





Timber frame elementsTIMBER FRAME



Timber frame elementsFLOORS









Timber frame elementsCROSS BRACING

system utilized to reinforce

building structures in which

diagonal supports intersect.

"Cross bracing can increase

a building’s capability to

withstand seismic forces

from an earthquake."

(Check source) The cross

bracing is usually seen with

two diagonal supports

placed in a X shaped

manner; these supports

withstand only tension.



Finite Element model







Our last work:CASA BERGANDI



Independent villa in Saluggia (Italy)





WALLS U= 0.18 W/m2K

FLOOR U= 0.14 W/m2K

ROOF U= 0.14 W/m2K

WINDOWS U= 1.40 W/m2K

VELUX U= 1.70 W/m2K

Medium height 5.20 m

Heated Surface 105 mq

Heated Volume 406 mq

ENERGY CLASS

A+



SOUTHERN side



WESTERN side



NORTHERN side



EASTERN side



Section B-B



Architectural model of the wooden elements