Best Facade - Start · 8 UCB Center Brussels NE / SW office - n.p. 9 Cité Lyon NE office - n.p. 10 EAL Vaulx en Velin NE school 11 Thiers Lyon E office - n.p. 12 Münchner Tor Munich

Best FacadeBest Practice for Double Skin Facades –WP 1 “State of the Art”

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Definition

“A double skin façade (DSF) can be defined as a traditional single façade doubled inside or outside by a second, essentially glazed façade. Each of these two façades is commonly called a skin.

A ventilated cavity - having a width which can range from several centimetres to several metres - is located between these two skins.

Steiff Factory, Giengen / Brenz, Germany, 1903

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Characteristic parts

• Exterior and interior glazing• Air cavity between the exterior and

interior glazing• Ventilation mode of the cavity• Shading device• Openings• HVAC system

Section showing constructive elements through the façade

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Typology of DSF

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Partitioning of the cavity

Ventilateddoublewindow

Juxtaposed:delimited bystorey and

facademodule

Corridor:delimited by

storey

Shaft box:inlet per storeyoutletshafts

Multistoreylouver

Multistorey

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Ventilation mode of the cavity

Indoor aircurtain

Outdoorair curtain

Air supply

Airexhaust

Bufferzone

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Analyzed Facades

name city orientation utilisation1 BiSoP Baden S / N school2 Felbermayr Salzburg S office - n.p.3 Fachhochschule Kufstein NW school / office - n.p.4 Justizzentrum Leoben SE office - p.5 Schubertstrasse Graz SE office - n.p.6 Aula Magna Louvain-La-Neuve SE other7 Sony Zaventem NE / SW office - n.p.8 UCB Center Brussels NE / SW office - n.p.9 Cité Lyon NE office - n.p.

10 EAL Vaulx en Velin NE school11 Thiers Lyon E office - n.p.12 Münchner Tor Munich N / S / E / W office - n.p.13 Geschäftsgeb. Süd 1+4 Munich N / S / E / W office - n.p.14 Zentralbibliothek Ulm N / S / E / W library15 A-A Holdings Athens E office - n.p.16 Alumil M5 Kilkis-Stavrochori E office - n.p.17 AVAX Athens E office - n.p.18 CGD Lisboa S office - n.p.19 Atrium Saldanha Lisboa SW office - n.p. / services20 ES Viagens / expo 98 Lisboa SE office - n.p. / services21 Palacio Sotto Mayor Lisboa SE services22 Torre Zen Lisboa S office - n.p. / services23 ABB Sollentuna/ Stockholm W office - n.p.24 Arlanda Stockholm N / S / E / W other (airport terminal)25 Glashuset Stockholm S office - p. / school26 Kista Kista / Sockholm S / W office - n.p.27 Polishuset Stockholm S / W office - n.p.28 Germany IBP VERU Holzkirchen W test facility

Facade

Greece NKUA

Nr. Country Partner

Austria IWT

Belgium BBRI

Portugal ISQ

Sweden WSP

France LASH-DGCB

Germany IBP

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Analyzed Facades

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Utilisation of BESTFAÇADE buildings

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Implementation and orientation of façades within BESTFAÇADE

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Type of ventilation and partitioning of the gap

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Types of room heating devices and used energy source of BESTFAÇADE buildings

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Types of room cooling devices and used energy source of BESTFAÇADE buildings

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Ventilation and air conditioning of BESTFAÇADE buildings

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Ventilation openings in outer shell of analysed façades

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Ventilation openings in inner shell

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Air flow in the gap in summer

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Integration of different devices into the façades (besides shading systems)

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Cost of DSF compared to conventional façades.

o p a q u e fa c a d e w ith w in d o w s

0

2 5 0

5 0 0

7 5 0

1 0 0 0

1 2 5 0

1 5 0 0

1 7 5 0

2 0 0 0

IB P

so u rc e

inve

stm

ent c

osts

[ €

/m² f

acad

e ar

ea ]

g la z e d fa c a d e

0

2 5 0

5 0 0

7 5 0

1 0 0 0

1 2 5 0

1 5 0 0

1 7 5 0

2 0 0 0

B lu m K o r n a d t S c h u le r

so u rc e

inve

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ent c

osts

[ €

/m² f

acad

e ar

ea ]

d o u b le s k in fa c a d e

0

2 5 0

5 0 0

7 5 0

1 0 0 0

1 2 5 0

1 5 0 0

1 7 5 0

2 0 0 0

B lu m K o r n a d t Da n ie ls W o lke S c h u le r

so u rc e

inve

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ent c

osts

[ €

/m² f

acad

e ar

ea ]

The blue and white fields show the range of cost mentioned in Blum (1998), Daniels (1997), Kornadt (1999), Schuler (2003) and own data.

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Additional cost of DSF according to different authors. The blue and white fields show the range of cost

0

250

500

750

1000

Blum Kornadt Schuler Kallinich Österle

source

addi

tiona

l inv

estm

ent c

osts

for

doub

le s

kin

faca

de

[ €/m

² fac

ade

area

]

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Potential advances of DSF

• Individual window ventilation is almost independent of wind and weather conditions, mainly during sunny winter days and the intermediate season (spring and autumn)

• Reduced heating demand thanks to preheating of outdoor air• Night cooling of the building by opening the inner windows is possible if the

façade is well ventilated• Improved security thanks to the two glazed skins• Better sound proofing from external noise sources e.g. at locations with

heavy traffic, mainly during window ventilation• More efficient exterior (intermediate) solar shading, as the shading can be

used also during windy days

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Potential disadvances of DSF

• Poorer cross ventilation and insufficient removal of heat from the offices rooms during windless periods, when ventilation is mainly provided for by natural ventilation

• Hot summer/spring/autumn days can lead to high temperatures in office rooms as a result of window ventilation

• Higher investment cost• The office floor area can be reduced• Risk of sound transmission via the façade cavity from one office to another

with open windows• Cleaning can result in additional cost• The energy saving potential has often been overestimated• Fire protection can be more difficult depending on the type of façade.

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Conclusion

• 28 façades of different buildings have been studied by means of a standardized questionnaire.

• Most of the buildings are office buildings followed by schools and service buildings. • Nearly all of the buildings have mechanical ventilation systems and both heating and

cooling are performed mostly by air heating/cooling systems. • The types of façades are mainly multi-storey and corridor types, in Belgium

juxtaposed modules are frequently used. • The façade gaps are mostly naturally ventilated (except for Belgium, where the

indoor air is led by mechanical ventilation via the gap to the centralized air handling unit).

• The shading is performed mainly with Venetian blinds located in the gap. • The cleaning of the outer shell is done via a cradle or a lifting platform, the glazing of

the gap is mainly cleaned from the gap or from the interior.

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Conclusion

• The cost of DSF are about 20 – 80 % higher compared to single glazed facades and about 100 to 150 % higher compared to opaque façades with windows.

• Therefore there have to be significant benefits in the HVAC system cost or the operating cost of DSF to make them more attractive compared to conventional façades.