Disturbance of transparency in the architecture of contemporary glass façades. Part 2

Marcin Brzezicki

doi:10.37190/arc210207

Abstract

Over the last two decades, new trends have emerged in the design of translucent façades. Those trends result from the dynamic technological progress and achievements in material engineering. The trends that are associated with the use of envelopes that interfere with the transmission of light through the façade are particularly interesting. This is strongly related to the significant transformation that took place in the dialectic of the building, the transformation of the “façade” into an “envelope”. The paper presents the author’s original distinction between the two most characteristic main sub-trends, distinguished based on optical phenomena occurring within the façade. The proposed division includes two main groups of disturbances: homogenous and heterogeneous. The former is present where panes of glass are used to disperse/diffuse light evenly, while the latter in façades with strong – usually printed – ornamentation. The article systematizes the issues of transparency disturbance in contemporary architecture and presents the typology of light-transmitting façades, in which this phenomenon takes place. The author also presents a matrix of relations that systematizes the presented case studies. Only this type of matrix makes it possible to illustrate an issue in which more than one variable is present. An assignment of the case studies to the trends and the determination of trend models are also included in the paper. The first part of the paper (published in March 2021) presents the introduction, methodology and simplified typology, the second one presents case studies, discussion and conclusions.

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2021

2(66)

DOI: 10.37190/arc210207

Marcin Brzezicki*

Disturbance of transparency in the architecture

of contemporary glass façades. Part 2

Introduction

Architecture communicates with the viewer through

the façade. Façades, apart from their function of the cover

and illumination, are the hallmark of the building – they

communicate its meaning and prestige. However, the

complexityoftherelationshipbetweenthedierentarchi

tectural “forms” and the “messages” makes contemporary

architecture not easy to understand or value. However, the

designers of “transparent” architecture do not always push

the glass/façade to be more and more transparent. Recent

trendsmaybefound,inwhich–alongwithsignicantfor

mal transformations – the pane of glass is losing its basic

optical feature of light transmission. In those façades, the

transparency is deliberately disturbed, and glass is no longer

chosen solely because of its basic function of light trans

mission, but also because of its other optical properties.

In the rst part

of the paper a distinction was made

intohomoandheterogeneousdisturbanceoftransparen

cy:twosubtrendswereobserved.Theformeronetakes

place where the whole surface of the pane is the source of

thesameopticaldistortion.Agoodexampleofthisphe

nomenonisalightscatteringpanethatmakesobjectslo

cated behind optically blurred. Homogeneous distortion

usually occurs when translucent, etched, or sandblasted

glass or acrylic) panes are used. Heterogeneous distur

bance – in contrast – takes place when some areas of the

pane change the path of the ray of light, while others do

not.This typeofdisturbance isthereforenot uniformly

* ORCID:000000023901144X.FacultyofArchitecture,Wrocław

UniversityofScienceandTechnology,email:marcin.brzezicki@pwr.

edu.pl

 M. Brzezicki, Disturbance of transparency in the architecture

of contemporary glass façades. Part 1,“Architectus”2021,No.1(65),

pp.77–84,doi:10.37190/arc210109.

distributed over the whole surface of the pane but is pres

ent only in selected regions. It is usually observed in the

caseofscreenprintedpaneswiththepatternorwhense

lective acid etching is applied to the regions of the pane.

First part of the paper addressed the issues of method

ology,denitionsandproposedthesimpliedtypologyof

lightdisturbingenvelopesin contemporaryarchitecture.

Matrix approach, case studies and the characteristics of

subtrendsbasedontheconductedanalysesaredemon

strated by the author in the presented second part of the

presented paper.

Case studies

Matrix approach

Thedenitionoftheclassictrendmodelinarchitecture

is based on characteristic features of the buildings belong

ing to the trend [1]. It is therefore common to and rank

orgroupbuildingsinaspecicorder,e.g.,chronological.

The disturbance of transparency is dierent. Presented

casestudiesincludefaçadesthatsimultaneouslyrepresent

features of homogeneous and heterogeneous disturbance,

andthosefeaturesarevisibleindierentintensity.This

rich diversity makes it impossible to make an unequivocal

typologicalassignment,ascasestudied[…]usually show

only some characteristics features, which are considered

to be representative for a given trend [1,p.89].Themodel

of the trend should include that variation as proof of the

internal trend’s evolution.

Typologically–fromtheperspectiveoftheconsidered

optical phenomena – all presented case studies with trans

parency disturbances can be shown in the form of a rela

tionalmatrix–seeFigure1.Thematrixillustratesthere

lation of the two criteria: the percentage of light scattering

and the density of the pattern. All intermediate values can

68 MarcinBrzezicki

Fig.1.Matrixapproachtothetypologyofcasestudies.Horizontalaxisshowsagradualtransitionfromtransparenttotranslucentpanes.

Vertical axis shows gradual transition from transparent to opaque glass through all intermediate stages of heterogeneous disturbances

(thedensificationofpattern).Casestudiesinclude:1.UnileverHausinHamburg;2.BuildingF,Tokyo;

3.DepartmentofNursingTakarazukaUniversity,Osaka;4.NewDeichmanLibrary,Oslo;5.MuseumofTransport,Lucerne;

6.DorintNovotelMesse,Munich;7.MuseuminWinterthur;8.Pier17,NewYork;9.HeadquarterSotaxAG,Aesch;10.SilesianMuseum,Katowice;

11.SpaceBlockNozawa,Tokyo;12.Kursaal,SanSebastian;13.BasqueRegionalLibrary,Bilbao;14.InterContinentalHotel,Ljubljana;

15.NoyoriMaterialEngineeringLaboratory,Nagoya;16.LVMH,Osaka;17.SoftwareandBiotechnologyPlants,Derio;

18.TipotieHealthCenter,Tampere;19.CliniqueduParc,Lyon;20.PlazaBizkaiaBuilding,Bilbao;21.TUDelftBuildingDepartment,Delft;

22.TownHall,AlphenandenRijn;23.IKMZ,Cottbus;24.JeanMermozHospital,Lyon;25.LouisVuitton,NewYork;

26.KiraritoGinzaDepartmentStore,Tokyo.Thecasestudiespresentedaredescribedindetailandshowninthechapter“Casestudies”

(photobyM.Brzezicki)

Il.1.Układmacierzowystudiówprzypadków.Ośpoziomapokazujestopnioweprzechodzenieodtafliprzezroczystejdoprzeświecalnej.

Ośpionowapokazujestopnioweprzejścieodszybyprzezroczystejdotaflinieprzepuszczającejświatła

przezwszystkiepośrednieetapyzaburzeńniejednorodnych.Opisprzypadków:1.BiurowiecUnileverHaus,Hamburg;2.BuildingF,Tokio;

3.WydziałPielęgniarstwaTakarazukaUniversity,Osaka;4.BibliotekaNewDeichman,Oslo;5.MuzeumTransportu,Lucerna;

6.HotelDorintNovotelMesse,Monachium;7.MuzeumwWinterthur;8.DomhandlowyPier17,NowyJork;9.SiedzibafirmySotaxAG,Aesch;

10.MuzeumŚląskie,Katowice;11.BudynekmieszkalnySpaceBlockNozawa,Tokio;12.SalakoncertowaKursaal,SanSebastian;

13.BaskijskaBibliotekaRegionalna,Bilbao;14.HotelInterContinental,Lublana;15.LaboratoriumInżynieriiMateriałowejNoyori,Nagoya;

16.DomhandlowyLVMH,Osaka;17.CentrumrozwojoweSoftwareandBiotechnologyPlants,Derio;18.CentrumZdrowiaTipotie,Tampere;

19.SzpitalCliniqueduParc,Lyon;20.BiurowiecPlazaBizkaia,Bilbao;21.WydziałBudownictwaTUDelft,Delft;22.Ratusz,AlphenandenRijn;

23.BibliotekaIKMZ,Chociebuż;24.SzpitalJeanMermoz,Lyon;25.DomhandlowyLouisVuitton,NowyJork;

26.DomhandlowyKiraritoGinza,Tokio.Przedstawionestudiaprzypadkówzostałyszczegółowoopisanewrozdziale„Casestudies”

(fot.M.Brzezicki)

bemapped.Thehorizontalaxisreferstothegradualtran

sitionfromtransparent(topleft)totranslucent(topright)

panes with all the intermediate steps that include panes

withanincreasingdegreeoftranslucency(or–fromthe

opticalperspective–anincreasingdegreeofhaze).The

vertical axis refers to a gradual transition from transpar

ent(topleft)toopaque(bottomleft)panethroughallthe

intermediatestepsofheterogeneousdisturbance(patterns

or ornaments gradually becoming denser). In simple terms,

itcanbesaidthatthehorizontalaxisillustratesanincrease

in haze/scattering of the image, while the vertical axis

illustrates the increase in the density of the ornamental

pattern.Thus,thepresentedmatrixallowsassigningcase

studies depending on their optical characteristics.

Disturbance of transparency in the architecture of contemporary glass façades. Part 2 69

Fig.2.Casestudiesarrangedaccordingtotheoriginalpositioninthematrix:

1.UnileverHaus;2.BuildingF;3.NewDeichmanLibrary;4.DepartmentofNursingTakarazukaUniversity;

5.MuseumofTransport;6.DorintNovotelMesse;7.HeadquarterSotaxAG;8.Pier17;9.SilesianMuseum;

10.SpaceBlockNozawa;11.Kursaal;12.BasqueRegionalLibrary(photobyM.Brzezicki)

Il.2.Studiaprzypadkówwukładzieanalogicznymdotegopokazanegowmacierzystudiówprzypadków:

1.BiurowiecUnileverHaus;2.BuildingF;3.WydziałPielęgniarstwaTakarazukaUniversity;

4.BibliotekaNewDeichman;5.MuzeumTransportu;6.HotelDorintNovotelMesse;7.SiedzibafirmySotaxAG,

8.DomhandlowyPier17;9.MuzeumŚląskie;10.BudynekmieszklanySpaceBlockNozawa;

11.SalakoncertowaKursaal;12.BaskijskaBibliotekaRegionalna(fot.M.Brzezicki)

Thescatteringofthetransmittedlightcanbemanifest

ed indierentdegreesof haze. Plastic membranes,due

toopticalparametersarecharacterizedbyalowhazeof

approx.5–10%.Thistypeofalmostalltransparentmem

branewas usedin theheadquartersoftheGermanfood

corporation Unilever Haus in Hamburg (arch. Behnisch

Architekten,2009).ThebuildingislocatedinHamburg’s

harbour and is exposed to violent gusts of cold wind. An

envelopemadeofETFEfoilwasdevelopedtoprotectthe

buildingandlowerheatlosses.Themembraneisstretched

on a tensioned stainless steel substructure. The unique

optical eect of a low haze is visible for both people

standing close to the building and observing from a dis

tance.TheETFEmembraneisnotperfectlytransparent

and the contours of the building visible behind it are gen

tlybutnoticeablyblurred–seeFigure2.1.

SmallBuildingF(arch.ToyoIto,1991)locatedinTo

kyo is an example of the gradual blurring of the image

visible behind the glass façade.Thedegreeofscattering

changes with the height of the building. At the eye level, the

glassistransparent,butthehazechangeswiththeheight

–thehigher,themorescatteredtheimageis.Theeectis

70 MarcinBrzezicki

interesting because the details of the interior visible through

theglazinggraduallyblurredupwards–seeFigure2.2.

Ontheotherhand,theFacultyofNursingofTakarazu

kaUniversityinOsaka(arch.TadaoAndo,2002)shows

thevisualeectoffull,homogeneousscatteringoflight

by the building’s envelope. In this case, a standard cur

tain mullionandtransom wall was constructed of light

scattering panels.Theeectofthedematerializationof

the building’s interior is absolute, no interior details are

visible. After dusk, the building turns into a lampshade

and radiates delicate, scattered light. In Oslo, the New

Deichman Library (arch. Lund HagemArchitects, Oslo

Atelier, 2020), features a similar façade but composed

of the panes of slightly dierent scattering parameters

(haze).Thepanesareplacedonenexttotheother,which

resultsinacharacteristicmosaiceectonthefaçade–see

Figures2.3and2.4.

Frequently, light scattering that takes place in the build

ing’senvelopeisnotashomogenousasinthecasestud

ies described above. Such a light scattering eect was

achievedintheresidentialbuildingSpaceBlockNozawa

inthesuburb ofTokyo (arch. C+A CoelacanthandAs

sociates,2005).Thesmallbuildinghousessmall,single

person apartments. An additional external envelope made

oflightscatteringglasslouverswasplacedatadistance

of60cmfromtheactualfaçadeofthebuilding.Thisspace

between the actual façade of the building and the envelope

is“similartothetraditionalJapaneseverandahengawa”

[2].Theeectof“hangingcurtain”isundeniablehere,but

thelightscatteringisnotuniformattheenvelope.While

details of the interior are blurred, the external appearance

of the building constantly changes depending on how

theresidentsoperate theglass louvers,seeFigure 2.10.

Incontrast–theoceandwarehousebuildingofHead

quarterSotaxAGcompany(arch.Itten+Brechbühl,2013)

In the year 2013, constructed inAesch, Switzerland in

2013–featuresapermanentfaçade,butwiththesimilar

eect.Theproductionpartofthebuildingwascladwith

an industrial curtain wall made of cellular polycarbonate

panels.Thecladdingscattersthelightandtheimageofthe

building’s interior is blurred, especially when direct sun

lightfallsonthefaçadeandthejointsofthepolycarbonate

panelsareclearlyvisible–seeFigure2.7.Asimilareect

has been achieved by using a translucent envelope of the

KursaalbuildinginSanSebastian(arch.RafaelMoneo,

1990).Theentirefunctionalprogramofthebuildingwas

dividedintotwoauditoriums.Thosetwovolumesaresur

rounded by a translucent envelope made of corrugated

ornamental glass, which is convex.The envelope blurs

the image of the interior both during the day and at night

when the building looks particularly attractive after dusk

–seeFigure2.11.

Characteristic haze can also be observed when light

isscatteredinthemassofthematerial.Thedepartment

store ofluxuriousbrandLVMH inOsaka(arch.Kengo

Kuma&Associates,2004)–seeFigure3.2,wascovered

with panes of glass, between which 4mm onyx panels

werelaminated.Thestoneplatesaresothinthatthelight

transmitted through shows an internal, milky, and veined

structure,uniquetoeachplate.Thearchitectemphasizes

that[…]light-permeable stone panels show the process of

transforming opaque material into an abstract and trans-

parent envelope by changing the expression of light night

and day[3].

Inmacroscaleornamentalpanesarecharacterizedby

irregularities of the surface much greater than the wave

lengthoflight.Thoseirregularitiesshouldberegardedas

asetofadjacentopticalelements:plates,prisms,concave

and convex lenses. Both, the way they are positioned and

the size of their curvature, visibly inuence the quality

image distortions visible for the observer. In the ornamen

tal glass, the image distortion always pertains to the rays

that are transmitted and is almost imperceptible regarding

reectedrays.

Depending on the size of the lenses used in relation

tothethicknessofthepane,thevisualeectoftranspar

ency distortionmaybedierent.Inthe Dorint Novotel

Messe Hotel in RiemArcaden, Munich (arch.Allmann

SattlerWappnerArchitekten,2004),largeglass“pleated”

channelproleswereusedtoformalighttransmittingen

velopewhichvisiblydistortstheimageofthefaçadeloc

atedbehind.Thearchitectscomparethefaçadetoa“stage

curtain”thatwavesandwaivesaway[4],[5].Incontrast,

nepatternpaneswereusedinthebuildingoftheSilesian

MuseuminKatowice(arch.PysalRugeArchitekten,2013).

In this building, the elements of the building’s infrastruc

ture were enclosed in cuboid volumes made of ornamen tal

glass. Due to the scale of the pattern, these panes, observed

from a distance, seem to be homogen eously translucent,

distortingtheimageof the objects locatedbehind – see

Figures2.6and2.9.

Glasschannelprolesarealsomanufacturedinaver

sionthatuniformlyscatterslight.Already inthe1990s,

architectsAnnetteGigonandMikeGuyerusedthemasan

envelopefortheMuseumbuildinginWinterthur,Switzer

land(arch.Gigon/Guyer,1999),andthen–inasimilarway

–fortheMuseumofTransportinLucerne(arch.Gigon/

Guyer, 2005) – see Figure 2.5. In the latter case, the

translucent envelope also serves as a showcase through

which exhibits related to the transport museum’s collec

tion could be observed – a kind of shadow box [6]. In

bothcases,thetranslucentenvelopecreatesadditionalin

betweenspacesurroundingthebuilding.Thebuildingin

Lucerneisoneofthebestexamplesoftheestablishmentof

additionaldepthwithinthebuilding’sfaçade.Thefaçade,

verysimilartothatoftheWinterthurMuseumofArt,was

designedandbuiltatthePier17shoppingcentre(arch.

SHoPArchitects,2018)inNewYork.Theenvelopemade

of translucent glass channel proles delivers additional

depth to the façade, which is particularly well visible in

thesunlight–seeFigure2.8.

In the proposed typological matrix approach, the het

erogeneous disturbance is illustrated on the vertical axis

–graduallyfromclear,transparentpanes(atthetop)to

thosecoveredwithadenselaceveilornament(atthebot

tom). One case study that seems to combine translucent en

velopeswithdenseornamentisthefaçadeofNoyoriMa

terialEngineeringLaboratoryatNagoyaUniversity(arch.

IidaArchishipStudio,2004).Thenorthernfaçadeofthe

building is enclosed by an envelope made of sandblasted

Disturbance of transparency in the architecture of contemporary glass façades. Part 2 71

made with the screenprinting technique using ceramic

paint, which melts with the glass when exposed to the tem

peratureofapprox.600deg.Asaresult,printisdurable

and resistant to environmental factors. Lightcoloured

(grey and white) inks are the most common because

theyallowprintingbinarypatterns(binarymeansthatno

halftoneisused).Suchlowdensitytypographicpatterns

have been applied to the façade of the Basque Regional

Library(arch.IMBArquitectos,2007)inBilbaoortothe

façade of the InterContinental hotel in Ljubljana (arch.

OFISarhitekti,2015)–seeFigure2.12.Onthecontrary,

glass.Thepanes,however,arenotuniformlytranslucent,

but they feature overlaying typographic transparent inscrip

tions:“NoyoriMaterialsScienceLaboratory”.Asaresult,

visualeectsvarydependingonwherethelightpenetrates

the envelope. In some regions, the interior of the building

is blurred, while in the others, clearly visible and easily

identiable.Asimilarvisualeectisalsovisiblefromthe

interior,seeFigure3.1.

However,veryoften[…]transparent panes serve only

as a scaolding/framework to create a sort of visual veil

[7, p. 10]. Patterned prints on the glass are commonly

Fig.3.Casestudiesarrangedaccordingtotheoriginalpositioninthematrix:

1.NoyoriMaterialEngineeringLaboratory;2.LVMH;3.SoftwareandBiotechnologyPlants;4.TipotieHealthCenter;

5.CliniqueduParc;6.PlazaBizkaiaBuilding;7.TUDelftBuildingDepartment;8.AlphenandenRijnTownHall;9.IKMZ;

10.JeanMermozHospital;11.LouisVuitton;12.KiraritoGinzaDepartmentStore(photobyM.Brzezicki)

Il.3.Studiaprzypadkówwukładzieanalogicznymdotegopokazanegowmacierzystudiówprzypadków:

1.LaboratoriumInżynieriiMateriałowejNoyori;2.DomhandlowyLVMH;3.CentrumrozwojoweSoftwareandBiotechnologyPlants;

4.CentrumZdrowiaTipotie;5.SzpitalCliniqueduParc;6.BiurowiecPlazaBizkaia;7.WydziałBudownictaTUDelft;

8.RatuszAlphenandenRijn;9.BibliotekaIKMZ;10.SzpitalJeanMermoz;

11.DomhandlowyLouisVuitton;12.DomhandlowyKiraritoGinza(fot.M.Brzezicki)

72 MarcinBrzezicki

Thefaçadeofthebuildingwascompletelycoveredwith

adoubleskinglassenvelope.Thetwopanesofglass,one

behind the other, are printed with the typographic pat

ternsmimickingupperandlowercaseletters,which[…]

have become so close to each other that they merge into

a single ornament that they cannot be distinguished [10,

p.62].Itworksinsuchawaythat[…]the printed pat-

tern breaks the reection, removes the hardness of glass

and homogeneous body makes the building [11]. In this

way,lighttransmittinglayersoftheglassenvelopecreate

aspecicopticalbuer.Thefaçadeisnot“at”,itsdepth

isdenedbythedoubledpatternappliedtobothsurfac

esofglassskin.Asimilareectofmultilayered“lace”

wasproducedonthefaçadeoftheocebuildingPlaza

BizkaiainBilbao(arch.Soriano&ArquitectosAsociados,

2006)–seeFigure3.6.Building’sfaçadeisenvelopedin

screenprinted curved glass ribbons that simultaneously

shadeocespaces.Inthiscase,asinnoother,thevisual

eect of many parallel veils is perfectly visible, where

[…]these surfaces tease the eye with no more than hints

and glimpses of the building’s inner life[12,p.1].

Although it seems to be no longer useful in terms of

illumination of interior, there are also façades in which

the screenprinted patterns occupy by percentage more

area than the part that is transparent. In those cases, the

patternbecomesmore important thantheglazing itself.

ExamplesincludetheLouisVuittonstoreon5

Avenue

inNewYorkCity(arch.JunAoki)ortheKiraritoGinza

departmentstore(arch.Jun Mitsui &Associates,2014)

–seeFigures3.11and3.12.

Discussion

Theauthorofthepresentedpaperbelievesthatarchi

tectural research should not be narrowed to the discussion

on façade’s optical parameters in detail only, but should

also formulate the answer to the question of architects’

motivation. The rst part of the answer is formulated

above: the panes that disturb light transmission – if used

skilfully – create an intermediate dematerializing zone

between the building and its surroundings. However, the

reasons behind such dematerialization seem to be very

dierent depending on the architect. For some, the en

velopeistheintermediatezonewherethevolumeofthe

buildingmergeswithitsbackground.Thistechniqueal

lows to skilfully blend buildings in with large volume or

unusualshapeswith the surrounding.Translucentenve

lopes “transmit” the colour of the environment and thus

favouragentleblendwiththeexistingcontext(especially

in the case of buildings with a small depth). In this way,

architecture “borrows” the context from neighbouring

buildings, and the formal merge of the old with the new

issmoother.Thismethodisuniversalanditisusedboth

inindustrialandpublicbuildings.Apositivebyproductis

thespectacular“lantern”eect,whichisinvisibleduring

the day, but dominant after dusk. Buildings illuminated

from the inside radiate the light in the night.

Thesecondpartoftheanswerfollowsfromtheobserva

tionthatlightdisturbingenvelopes,ingeneral,dierfrom

classicalstoneorbrickfaçadesinawaythatadierentset

slightlydenser,nontypographicprintswereused atthe

façadeoftheTipotieHealthCenterinTampere,Finland

(arch.SiggeArkkitehditOy,2013)andtheSoftwareand

BiotechnologyPlantsinDerio,Spain(arch.CollBarreu

Arquitectos,2006).Theguresillustratetheeectofthe

veil, which was achieved by applying the pattern on the

glass pane in the façade of the building in Derio – see

Figures3.3and3.4.

Denserpatterns entaildierent visualphenomena. In

thecaseoftheCliniqueduParcbuildinginLyon(arch.

Xanadu,2007),awhite geometrical pattern inspiredby

AlexanderGirard’sfabrics–the“CheckerSplit”pattern

– was applied to the entire glass envelope of the build

ing[8]–seeFigure 3.5.The patternis sodensethatit

isdiculttorecognize thedetailsbehindit. Moreover,

evendenserornaments are alsoused(with adensityof

over40–50%).TheglasspanesatthefaçadeoftheJean

MermozhospitalinLyon(arch.F.H.Jourda,2008)have

been repeatedly overprinted in several colours – see Fig

ure3.10.Thisoperationleadstotheuniquevisualeectof

gradual transparency: in the upper part, the pane is almost

transparent, while on the lower part of the pane patterns

are denser and overlaid. In both cases, the dense pattern

actslikeapatternedveil,makingitdiculttoseewhatis

hidden behind.

However, there are screenprinting techniques avail

able, that allow producing halftones with the use of small

dots.Thedotsofdierentsizeorspacingsimulateagradi

ent by means of density. In this way, the light transmission

isnotbinaryasinthecasestudiesabove–butgradual,in

manyintermediatesteps.Theseprintingtechniquesmake

the glass look similar to the traditional silk curtain that is

hunginthewindows.Theyalsoworkverysimilarlyinop

tical terms. Such halftone prints depicting stone blocks in

crosssectionwereshowedonthefaçadeoftheBuilding

DepartmentofTUDelft(arch.JeanneDekkersArchitec

tuur,2007).Just asitisthe casewithan envelope sur

rounding almost the entire town hall building in Alphen

andenRijn(arch.ErickvanEgeraatassociatedarchitects,

2003),wheretheglassisprintedinaleaflikepatternwith

varying degrees of light transmission.The eect of the

veil is visible both from the outside and the inside – see

Figures 3.7 and 3.8. The architect addresses the enve

lopeusedasfollows:[…]glass envelope, comparable to

a gauze veil – an element of fashion that conveys a mys-

terious lack of denition. Yet indicates or proves insights

into what is behind[9,p.007].

Newtrendsinarchitecturedonotrejectornament,but

an ornament in its historical version is not used anymore.

Asseenabove,newscreenprintedornamentstaketheform

ofregularpatterns,freeformshapes,includingtypographic

ones.Theyoftenrepresentthesocalledmimeticornament,

i.e., the ornament that is closely related to the function of the

building(mimetism–theactorartofcopy

ing or imitating

closely; mimicking). Halftones allow also to reproduce

pictures, photographs, and drawings. This type of half

toneprintwasusedinthebuildingoftheIKMZTechnical

Library (Informations, Kommunikations und Medien

zentrum)inCottbusofBrandenburgTechnicalUniversi

ty(arch.Herzog&de Meuron,2004)–seeFigure 3.9.

Disturbance of transparency in the architecture of contemporary glass façades. Part 2 73

ofstylisticdevicesisused.Nonlighttransmittingfaçades

gettheirnalformoncethattheyarebuilt,andtheirap

pearance for the observer is determined by the play of

lightandshadow. Incontrast,lighttransmitting façades

aremuchmorelightdependentthansolidmaterialfaçades

becausethelighttransmissionandreectionthroughglass

is much more unpredictable and – so to speak – chaotic.

Therefore,aslightchangeinthelightingconditionsmight

result in a fundamental change in the façade’s appearance.

It is also frequently observed that the elements of the

building located behind the glass envelope are either hard

tospotorsodistortedthattheyarealmostunrecognizable.

Usually, the purpose of such a stylistic operation is to play

withtheobserver,tomobilizetheimagination,asinsome

cubistic and impressionistic paintings, where the viewer

is invited to play a game of guesswork and willingly takes

partinone.However,theintentionsmaybedierent.In

the case of ornamental glass or rich printed patterns, the

architect’s intention seems to be focusing the observer’s

attention on the envelope, not on what happens behind

it. It’s a technique of formal distraction, where architect

provides a more aesthetically comprehensible message,

insteadofthediculttoacceptminimalistsimplicity.

The third part of the answer is related to an evident

trend of “redundancy” in the architecture of contempo

rary transparent façades, which was already observed,

analysed, described, and published by the author of the

presentedpaper[7].Thetrendischaracterizedbythear

chitect’s need to introduce phenomenal or literal depth

within the façade. Many people (including users and

clients)aresimplynotwillingtoacceptat,glazedcur

tainwalls,coldandimpersonal.Theyarelookingforthe

experience of depth, the third dimension strongly asso

ciated with the classical façade, the depth which could

be achieved with the use of various architectural stylistic

devicesandaestheticalmeans.Thelightdisturbingenve

lope laid over the actual building’s façade might be con

sidered an answer for such a pursuit.

Conclusions

Theliteraturestudiesandcasestudyanalysisconduct

ed by the author show that the main idea of the new trend

is manifested in the departure from the literal message

that is conveyed through conventional façade. This di

rect and clear message – as in the case of the transparent

glass–isreplacedbyavagueandhazyimagedisplayed

ontheenvelope, somethingunsureand temporary[13].

Thedominanteectisthelossofobviousnessandper

hapsambiguity.Thisquestionablecharacterofthefaçade

is moved to a higher level, not only is nothing certain but

evenwhatonemightsupposeseemsunobvious.Thiscan

be understood as an architectural interpretation of the cur

rent condition of the world, full of anxiety and challenged

paradigms.Themainideasofpostmodernismaredened

byscepticism,irony,andrejectionofthegreatnarratives

and ideologies of modernism, often undermining vari

ousassumptionsofEnlightenmentrationality.Similarly,

the building envelope, as the main arena of architectural

expression,hasbecomeaplaceof[…]the production of

surcial eects, both as an environmental and a security

device and as the vehicle that will produce the building’s

facialization[14,p.158].

The very new transparency is characterized by the

promisethatthefaçademakestotheobserver.Theprom

iseofexposingsomething.AsPelkonenwrites:The veil

[…]implies wrapping that can be removed. It suggests

secrecy yet promises revelation[15,p.122].Glassceases

to be a “mediator” which connects the interior and ex

terior space but becomes a bearer of a completely new

content.Givingupthetransparencyinfavourofitsdis

turbance, the appearance of the building will be shaped by

optical phenomena that have not been used in architecture

so far, and envelopes that block the penetration of light

rather than support it. As Mies van der Rohe wrote, the

image of façades built of transparent materials consists of

rays of lightpassingthroughandreected[16].There

fore – as stated above – the appearance of a translucent

façade is determined by scattering, multiple reections,

refraction, the phenomena that are much less predictable.

As Kengo Kuma wrote, […] architects today are more

sensitive to the fact that glass is always caught up between

the various phenomena that take place on its two sides,

and are eager to experiment with a new type of transpar-

ency while developing increasingly ambiguous denitions

of enclosure[13,p.30].Andfurther–nottoquoteliterally

–Kumawritesthatglasspanescontributetothesmooth

and changeable quality of the architectural space, they

buildandatthesametimetheydestroy.Asaresult:[…]

boundaries are blurred not only between inside and out-

side but also between what is perceived as real and virtual

[13,p.30].Theserepeatedattemptstoexperimentwith

alighttransmittingenvelopearealsooneoftheimportant

characteristics of the trend in question.

From the perspective of visual eects perceived by

the observer, a transparencydisturbing envelope is used

atleastinseveralspatialscales.Theycanbedividedinto

those that are applied to the whole volume of the build

ing, and those that interact on a smaller scale of a single

pane.

Concerning the whole volume of the building – as it

was addressed above – the envelope is often used to soften

the boundaries between the interior and the exterior. At the

scaleofindividualpanes,itsinuencemaybedierent,de

pendingonthespecicdegreeoftransparencydisturbance

of a given pane.

Assignment of case-studies

All the analysed case studies have been assigned by

theauthortothetrendoftransparencydisturbance.Two

clearsubtrendscould bedistinguishedwithin themain

trend:homogeneousandheterogeneousdisturbance.The

formerincludescasestudies1–12and16,whilethelat

terincludescasestudies13–14and17–26,withthecase

studynumber15beingcharacteristicforbothsubtrends.

However, it seems that in order to explain the intricate

structure of various optical phenomena, it is much more

usefultoorganizetheminamatrixsystem,whichallows

determining the gradual occurrence of the features of these

subtrendsinagiventypeofenvelope.Asaresult,both

74 MarcinBrzezicki

theextremesandintermediatestatesndtheirtypological

assignment. This operation was performed in section

“Matrix approach”.

Definition of the main trend and sub-trends

Basedonthepresentedanalyses,itispossibletodene

a model of the main trend by giving its characteristics fea

tures.Themainfeatureoftransparencydisturbingenve

lopesisthevariabilityofvisualeectsproducedonthe

façadeindierentlightingconditions.Indeed,atranspar

ent façade is also susceptible to the change of light, but

thischangeisnotqualitative,butquantitative.Thear

mation of the achievements of material engineering that

allows changing the optical parameters of the pane might

also be mentioned as an important common feature of

thepresentedcasestudies.Thisadvancedmaterialtech

nology is frequently used to achieve even more pictorial

graphical results on the façade providing tools for a new

understanding of transparency as a feature of the façade

itself. Those new technologies of printing, laminating,

and dyeing allowed us to obtain new formal and visual

appeal in envelopes. A focus of the observer’s attention

ontheenvelopeisalsotypicalforthepresentedcasestud

ies. A brief analysis also shows that innovative materials

imply the emergence of new, diverse architectural forms

– especially new types of additional envelopes that at

tract the attention of the public. It can be assumed that the

common goal of the main trend is to achieve innovative

visualeects,withagreatvarietyofarchitecturalforms.

The similarityoftheworks built by dierentarchitects

is visible when they try to solve a similar problem, using

materialsofsimilarparameters.Theprimacyoftheform

over the structure is also characteristic of the presented

examples.Thestructureisusedinapurelyutilitarianway,

itservesasascaolding,towhichtranslucentorpatterned

panes are mounted.

Italsoseemsjustiedtostatethatthearchitects[…]at

all stages of the design process, in addition to the ration-

al premises, also took into account the formal ones [17,

p.54].Theyhadtotakeintoaccountallthefactorsthat

usually determine the appearance of the façade and, addi

tionally,thoserelatedtotheapplicationofalightdisturb

ing envelope. This process requires, for example, care

fulanalysisofsignicantchangesinthewaythefaçade

operates in optical terms, which may aect workplaces

illumination. The prediction of lighttransmitting quali

ties of the façade calls for the determination of the feature

named envelope’s directionality, i.e., what should be seen

from the outside and how the building’s façade should be

perceivedfromtheinside.Thisisalegitimateapproach,

certain façades are designed from scratch with the night

appearance in the mind.

Themaintrendoftransparencydisturbanceconsistsof

twosubtrends,whichhavetheirseparatedistinctivefea

tures. Homogeneous disturbance subtrend is character

izedbythereductionoftransparencyoftheenvelopeto

wardstranslucency(usuallywiththeuseoflightscattering

materials)overitsentiresurface(dierentdegreeoccurs

in dierent cases), while the heterogeneous subtrend is

characterizedbythelocalblockageoflighttransmission,

disturbedthroughthepattern,printing,ornament.Thelat

tersubtrendisalsocharacterizedbytheuseoftypography

and mimetic ornaments. Envelopes that homogeneously

disturb transparency are usually perceived by the audience

as restrained, calm and even metaphorical, while those

heterogeneous are considered dynamic and, due to their

expressivepattern,sometimesevenaggressive. Jadwiga

Sławińskausedtodescribethistypeofapproachas“dec

orative facadism” [18], which is a kind of protest against

the use of plain modernist transparent curtain walls.

Theuseoflightdisturbingenvelopesseemstobeunre

latedtothefunctionofthebuilding.Thecasestudiespre

sentedinthepaperfullthefunctionofbothprivatehouses

andpublicbuildings,oces,anddepartmentstores.How

ever,itshouldbenoted,that3outofthe26casestudies

representhealthcarefacilities(cases4,19,24).Thismay

be related to the need for increased privacy, but this re

lationship has not been proven and should be treated as

a coincidence.

Trend development in the time

Based on the presented summary made to create a sim

plied typology, it could be concluded that the experi

ments with the disturbance transparency started in the

early1990sandreachedtheirapogeeinthemiddleofthe

rstdecadeofthe21

century. However, this conclusion

is not entirely valid. Currently both trends – homogen eous

and heterogeneous disturbance of transparency – are ac

tiveinarchitecture.Forconrmation,onecanrelyon

the

recentlycompletedbuildings,suchastheoceandware

housebuildingofHeadquarterSotaxAG,thePier17shop

pingcentreinNewYork,andtheNewDeichmanLibrary

in Oslo.

Future research

Thepresentedarticledemonstratesonlyasmallexcerpt

ofthedatabaseoffaçadessurveyedbytheauthor.Thisda

tabaseisstillbeingexpanded.Theauthorplanstodeepen

the study of various, currently developing formal trends.

Itisjustiedtoaskthefollowingquestionsfor:(i) archi

tectural theory issues based on architects’ statements and

analysisofcritics’opinions;(ii) technical issues – dimen

sional analysis of façades in crosssection, proportions,

and spatial relations; (iii) functional issues – e.g., what

implications the disturbance of transparency poses for the

building’s users.

Summary of part 2

An envelope “rich in ornamentation” and a “tempting

veil”aretwodierentdesignstrategiesinthedisturbance

of transparency, leading to dierent visual phenomena.

Theircharacteristicsbasedonconductedanalysesarepre

sentedbytheauthorinchapter“Denitionofthemaintrend

andsubtrends”.However,acomplete,nalandnished

formulation of the trend’s model seems to be impossible.

The basic reason for this is the fact that the discussed

Disturbance of transparency in the architecture of contemporary glass façades. Part 2 75

trends in architecture are still active and constantly chang

ing, e.g., there is plenty of still ongoing construction

(cf.chapter“Trenddevelopmentinthetime”).Theclear

image of the trend is also blurred by the fact that many

of the original solutions are later copied by imitators, de

generating initial ideas. An example of such an activity

isthecommonpracticeofllingmodernistmullionand

transomcurtainwallswithpostmoderntranslucentglass.

Thisleadstoakindofdissonance,inwhichatechnical

solution primarily created to ensure perfect transparency

is used to contradict it.

Theprocessofthegradualerosionoftransparencyhas

led not only to the devaluation of the initial meaning of the

termonthesemanticlevel(bothopticalandorganization

al) but also to a real loss of transparency in favour of other

opticalphenomena.Manipulationoftransparency[…]be

it through colouring, veiling, tilting, or warping, has be-

come the new curtain wall standard. The ideal crystalline

transparency at the heart of the original curtain wall as-

semblage has recently been replaced, yet incrementally,

by the acknowledgment and celebration of a necessarily

distorted, diverse, and heterogeneous mix of eects and af-

fects – a new reality[19,p.915].Thisentailsconsequences

not only for the way the architectural form is perceived,

butalsofor its meaning.The formisnot nallydened

bythedesignerbutinuencedbythemomentarystateof

theatmosphere(daylight)orarticialinternallighting.In

architecture, transparent glass oscillates between the trans

missionoflightanditstotalreection,whilelightscatter

ingpane–betweentranslucencyandtotalopacity.Enve

lopes that scatter, refract or block the course of the light

rays, symbolically compete with the direct message com

municating the intentions of the “sender” – an architect or

a client. As a result, transparency and the associated con

tinuity of architectural space – perhaps the most important

achievementofmodernisminarchitecture–havesuered

most. However, in contrast to reective glass acting as

aonewaymirror, thedisturbanceoftransparencyworks

in two directions,itaectsbothpeoplewho are outside

the building and those who are inside. In this metaphorical

view, the light disturbing envelope does not prefer anyone,

the trend is much more “democratic” than others that are

present in contemporary architecture.

Translated by

Marcin Brzezicki

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Acknowledgements

This paper was funded by the National Science Centre, Poland grant

entitled: “New trends in architecture of transparent façades – formal

experiments, technological innovations”, ref. no. 2014/15/B/ST8/00191.

Various elements of simplied typology have already appeared in the

author’s previous publications [7], [20] but were not described in such

detail. The case studies shown there have not been systematized in the

form of a matrix system before.

76 MarcinBrzezicki

Abstract

Disturbance of transparency in the architecture of contemporary glass façades. Part 2

Overthelasttwodecades,newtrendshaveemergedinthedesignoftranslucentfaçades.Thosetrendsresultfromthedynamictechnologicalpro

gressandachievementsinmaterialengineering.Thetrendsthatareassociatedwiththeuseofenvelopesthatinterferewiththetransmissionoflight

throughthefaçadeareparticularlyinteresting.Thisisstronglyrelatedtothesignicanttransformationthattookplaceinthedialecticofthebuilding,

thetransformationofthe“façade”intoan“envelope”.Thepaperpresentstheauthor’soriginaldistinctionbetweenthetwomostcharacteristicmain

subtrends,distinguishedbasedonopticalphenomenaoccurringwithinthefaçade.Theproposeddivisionincludestwomaingroupsofdisturbances:

homogenousandheterogeneous.Theformerispresentwherepanesofglassareusedtodisperse/diuselightevenly,whilethelatterinfaçadeswith

strong–usuallyprinted–ornamentation.Thearticlesystematizestheissuesoftransparencydisturbanceincontemporaryarchitectureandpresents

thetypologyoflighttransmittingfaçades,inwhichthisphenomenontakesplace.Theauthoralsopresentsamatrixofrelationsthatsystematizesthe

presented case studies. Only this type of matrix makes it possible to illustrate an issue in which more than one variable is present. An assignment of

thecasestudiestothetrendsandthedeterminationoftrendmodelsarealsoincludedinthepaper.Therstpartofthepaper(publishedinMarch2021)

presentstheintroduction,methodologyandsimpliedtypology,thesecondonepresentscasestudies,discussionandconclusions.

Key words:transparency,theoryofarchitecture,façadeglazing,printingonglass,coatingsonglass

Streszczenie

Zakłócenie przezroczystości w architekturze współczesnych szklanych fasad. Część 2

Wciąguostatnichdwóchdekadpojawiłysięnowenurtywprojektowaniuprzezroczystychfasad.Sąonewynikiemdynamicznegopostęputech

nologicznegoiosiągnięćwdziedziniemateriałoznawstwa.Szczególniemanifestująsiętenurty,którezwiązanesązzastosowaniempowłokzakłó

cającychprzenikanieświatłaprzezfasadę.Wiążesiętosilniezistotnąprzemianą,któradokonujesięwdialektycebudynku,zprzemianąfasady

(ang.façade)wobudowę/powłokę(ang.envelope).Wartykuleprzedstawionodokonaneprzezautorarozróżnieniezjawiskoptycznych,którezacho

dząwobrębiefasady.Proponowanypodziałobejmujedwiegłównegrupy:jednorodneiniejednorodnezniekształceniaprzezroczystości.Tepierwsze

występujątam,gdziezastosowanotaerównomiernierozpraszająceświatło,tedrugienatomiastwfasadachosilnej–zazwyczajnadrukowanej

–ornamentacji.Artykułsystematyzujezagadnieniazniekształceniaprzezroczystościwarchitekturzewspółczesnejiprzedstawiatypologiętychfasad

przepuszczającychświatło,wktórychwystępujetozjawisko.Wartykuleprzedstawionoteżmacierzrelacyjną,którasystematyzujeopisywanestudia

przypadków.Jedynietentypmacierzypozwalanapokazaniezagadnienia,wktórymobecnajestwięcejniżjednazmienna.Wtekściedokonano

równieżprzypisaniastudiówprzypadkówdonurtów,atakżecharakterystykisamychnurtów–stworzeniaichmodeli.Pierwszaczęść(opublikowana

wmarcu2021r.)zawierawstęp,opismetodologiiorazuproszczonątypologię,a w drugiejznajdująsięstudiaprzypadków,dyskusjaorazwnioski.

Słowa kluczowe:przezroczystość,teoriaarchitektury,szklanafasada,nadruknaszkle,powłokinaszkle