Additionally, facade keeps on expressing thè appearance of thè architecture, so that thè building envelope needs to suit formai and aesthetical requisites too.

Within thè topic building envelope, transparent facade is probabiy thè one on which more efforts are concentrated: since thè spread of thè Modernism - glass is an icon of modern architecture - architects and common people have been fascinating by thè transparency and lightness of this type of cladding surface. It wouid be incorrect to affirm that no changes - in tochnology, materiais, design and construction methods - have occurred from thè first curtain-walls' realizations, but relevant improvements are stili necessary to drive this component - but also many other branches of thè building industry - toward a more efficient and sustainable construction.

Buiiding industry is extremely conservative. Facade industry claims to be one of thè most innovative fieids of thè construction, but if compared to many other produci industries, innovation in architectural envelope is quite poor. There are many reasons for this situation and it is not easy to carried out radicai changes able to shake thè ordinary in market, production and methodology, promoting innovation. However, a big step forward is now taking piace: architecture - and facade too ' seams to move from a mechanical paradigm to a new informatics paradigm.

Dynamicity, customizability, changeability, integrality, ephemeralness are some of thè - potential - features of thè new generation of building skin. Lì is noi possible to foresee thè success and thejnfluence of this change on thè worid of construction: nevertheless, it appears an extremely promising and interseting topic for architects. Liquid facadesjnnovative concepì and technologies for thè building envelope ofthe future is an investigation on thè use of liquids in transparent facade. It is a collection of principles and concepì design proposais for new, adaptive building skins, where liquids are used within transparent, glazedelementstoperformdifferenttasks-withoutchangingradicallythe appearance of thè facade and maintaining a high degree of transparency. Thè topic liquid facade is faced with a multidisciplinary approach, keeping together thè different sides of thè question - aesthetical features, building physics, technology, design of construction and many others. To reach this goal, reflections and analyses on thè several fieids involved in thè concept design procedure are necessary. Therefore, Liquid fagades is not oniy a list of proposais. It is an overview on current facades' panorama, it faces climate requirements and building envelopes' efficiency, it reflects on thè features and design methodology for thè new generation of

building skins.

In particular, thè first chapter deais with thè role of thè facade in contemporary architecture and provides some relevant examples of current trends in facades and architectural design. It also analyzes and describes thè paradigms of contemporary building skins that are useful to understand today's situation and - try to - foresee future developments in thè building envelope.

In thè second chapter, elements of environmental comfort a climate requirements are provided, as well as basic physical principles involved in thè performance of thè facade. Despite thè brief overview on these concepts - which is definitely not exhaustive - notions and observations contained on this chapter are mandatory to face thè concept design phase. Additionally, some information and basic principles ofthe adaptive envelope are presented too.

Current technologies for transparent envelope are classified in chapter three. Here, post-and-beam facades, prefabricated modular facades, doublé skin facades and component facades are described, together

with a wide set of examples and technological details. Thè understanding of current technologies and construction design is a cruciai part of thè knowledge that is necessary for thè development of new proposai for facade.

Chapter tour contains some reflections on thè lack of innovation in thè facade industry and in thè whole building industry. Moreover, it outiines relevant information about this topic to provide architects instrument for promoting and leading thè innovation process in building technology.

Finally methodology of concept design, which is assumed as a key aspect for thè innovation and for thè definition of proposais for liquid facades, is described in detail.

According thè paradigms of current and future facade described in thè first chapter, chapter five provides a list of driving forces and supporting elements for thè development of possible future building skin. Here, once again thè future facade is envisioned being a living interactive component, necessary to increase thè sustainability of thè construction. Thè chapter contains also a brief introduction on thè topic liquid facade, demonstrating thè potentiais and thè positive attitude that liquid facades show. Finally, two examples of existing liquid facades are described, in order to confirm thè effective realizableness of these technologies. Thè following chapter contains six proposais for liquid facades under thè form of concepts design, developed with a multidisciplinary approach.

Three groups of liquid facades have been identified, according to thè different tasks of each liquid facades' class: liquid facade as a solar collector and ciimate contro! system; liquid facade for thè visual comfort; multimedia liquid facade. Thè chapter ends with some suggestions for combinations of liquid facades.

Thè last chapter presents a criticai review of thè research and concept design work presented in this report. Additionally, it envisions some of thè cruciai challenges for thè next generation of facades, outiines thè key aspects to be further investigated for thè successfui outcome of liquid facades and invite architects to take responsability for promoting innovation.