Robert Kronenburg argues that buildings have long complicated lives. During this time their parameters of use can change widely and diversely. Buildings are built on permanent sites that may only change appearance over very long periods if ever, although the built and living environment around does change. This may result from the redevelopment or replacement of buildings as well as how they are used. To give an example of this, the building function might change, i.e. warehouse to dwelling, shop to office. Also considering the evolution of function, it is possible that if the building's essential purpose does not change, its functions can develop beyond recognition. For Kronenburg this is a very important topic confronting architecture for today's society and its future. He believes that our ambition is our need for change and improvement  .
Bernard Leupen, Jasper Van Zwol and René Heijne take the position that architecture is not a timeless medium. In the introduction to their 'Time based Architecture' they write that today's society is changing so fast, buildings are now faced with new design issues which the architect has to be in a position to meet by designing the building accordingly  .
Frank Bijbendijk argues that modernism was based on the idea that a building, structure and space were designed on the premise that it fulfilled a specific function. This approach was taken because it was believed it was possible to calculate very accurately the form that was suitable for the given function. The process made the assumption that; "If people have uniform needsâ€¦â€¦..we can accurately predict beforehand which functions a building must fulfil. For each function we can precisely determine the space needed for it"  . He expands on this by explaining that at first sight this approach makes sense, but while one can argue about the importance of fitness for purpose, he argues how it was applied caused numbing repetition, isolation and to buildings with no future worth to society. Herman Hertzberger argued that functionalist architecture is based on the expression of efficient purpose. He believed this concept did not cope with the variable of time.
"The rapid obsolescence of all too specific solutions leads not only to disfunctionality but also to serious inefficiency"  .
For Hertzbeger, within the complex situation of architecture, the functionalist approach resulted in too specific a response. He argues that this caused fragmentation instead of integration of human needs.
Suitability for function:
Fitness for purpose is explained by Leland M Roth in his 'Understanding Architecture'. He describes how Vitruvius defined good architecture into three categories 'utility, firmness and beauty'  . Utility meant the functional arrangement of rooms and spaces of the building without hindrance to purpose, in other words it meant suitability. Jacques-François Blondel refined the term in the 18th Century calling it 'convenance' which basically translated into fitness for purpose. For Blondel, 'convenance' outlined the relationship between the building and its inhabitants;
"For the spirit of convenance to reign in a plan, each room must be placed according to its use and to the nature of the building, and must have a form and a proportion relative to its purpose" 
Fitness for purpose in Blondel's definition, in inter alia that the arrangement of a plan should be related to its purpose. Fitness for purpose was thus, an organizational principle. Adrian Forty describes how J.C. Loudon in the 1830's also categorised fitness for purpose as an expression of the end in view  . This can be interpreted that the end in view is the purpose the building is to serve at any moment.
Alan Colquhoun's definition of function has two variations of overall meaning. The first is that a building must satisfy a set of practical uses. The second is that it represents a relationship with its society in which it is built, in other words a sense of belonging to its age. It must convey an emotional function  . An emotional function is a relationship between society and its working parts or underlying process of its culture.
Kronenburg states that architecture designed to be able to adapt understands the future is not finite and that change in needs and circumstances is inevitable. He argues that a framework is an important element that will allow change to take place. For him;
"Adaptable buildings are intended to respond readily to different functions, patterns of use and specific user requirements" 
This kind of architecture is when an architect takes a building solution to a be a permanent form but within it, the elements are designed such that changes in specific requirements can be accommodated and also changes in use completely. The important thing is that it is designed for a specific use at the time of design but that overtime the buildings contains an ability to facilitate change.
Adrian Forty describes how Prussian philosopher Wilhelm Von Humbolt in his publication, 'On Language' in 1836 believed language was governed by a common underlying synthax. It was not a form but rather a structure. In 1915 Ferdinand de Saussure a Professor of Linguistics expanded on the topic of language concluding that the structure of language was not about how it functioned or what it meant. Rather to study language was to study the differences within the system  . Mark Gelernter in his 'Sources of Architectural Form' describes how linguistics in this new approach realised that behind different languages around all human cultures there is a common structure of which all individual languages are variations. Gelernter adds that this suggested that the structure must be constructed into the human mind.
"The universal structure of the human mind allows of a large but not infinite number of possibilities, and the individual cultures responding to localised conditions, previous traditions and so on, work out their own specific variations within this framework" 
The anthropologist Claude Levi-Strauss applied this idea to the differences between language and speech. Within the fixed framework of language there are many ways to communicate what you want to say. Herman Hertzberger describes how Strauss argued that this framework makes speech understandable to the listener but that speech is also an interpretation of language and overtime it can also influence how that language is spoken. Both determine each other and are therefore relate to each other dialectically  . For Hertzberger a fixed framework does not restrict freedom but rather creates it.
Herzberger takes this into architectural terms by arguing that form of architecture is like that of language and can be considered as a structure. He believes that overtime a building can also be influenced or interpreted in different ways by the occupants and they can also be influenced by it much like the relationship between language and speech. A building's capacity for change can be measured by its 'competence', how it is interpreted.  . Competence for Hertzberger is polyvalence.
"We must continuously search for archetypal forms which because they can be associated with multiple meanings, can not only absorb a programme but can also generate one. Form and programme evoke one another" 
Hertzberger believes polyvalency is the best and most appropriate approach to this principle of change of use. The building remains permanent but has the ability of adaptability within it, by being able to process changes without changing itself as a whole..
Case Study of Interpretation - The Amphitheatres of Arles and Lucca
During the Middle Ages and up until the 19th C, the Arles amphitheatre in France was transformed and inhabited as a small walled town or fortress for protection. Its internal organisation maintained the oval pattern and formed concentric rings towards the centre.
During the same period in history the amphitheatre in Lucca was absorbed by the surrounding town but the open oval space in the centre was retained as a public square while the structure of the amphitheatre was remodelled into dwellings.
Both amphitheatres were absorbed by the surrounding environment to serve a new function but both were influenced by the form of the amphitheatre.
"These ovals represent an archetypal form - in this case that of the enclosed space, an interior, a large room which can serve as work-place, playground, public square and place to live. The original function is forgotten, but the amphitheatre-shape retains its relevance because it is so suggestive as to offer opportunities for constant renewal" 
These amphitheatres had the ability to change appearance and function to cope with changing circumstances but with the underlying structure (form) essentially not changing itself. Both buildings showed a polyvalence to absorb a new function through their archetypal forms. Therefore it is the form that remains the same forming a new identity.
These examples are interesting considering Frank Bijbendijk argument that for a building to be adaptable it needs to be permanent and contain an identity that can be related to. This identity is an emotional value, or as he calls it 'Preciousness'. This is achieved by its continued use within society. For him buildings that offer freedom for future use adds to their value over time and thus forms an identity that can be related to. The amphitheatres show this process. Change for him is a constant factor but the problem is, as he points out, that future use is impossible to predict.  . In the case of this study, the form created the identity and the ability of change within it without predicting the future needs.
Performance for Herzberger is how a building is interpreted in a specific situation. He argues that building order anticipates the performance that may presumably be expected of it in a given situation. It acts as a permanent framework in which polyvalence can take place and is achieved through structure creating freedom of appropriation. For him the building order enables the freedom of use to which it will be put, now and in the future by allowing the architect to hypothetically program in all expected infill's of function,.
For Leupen, polyvalence in the context of public buildings is different in the private dwelling. In the public building it means that the space is capable of accommodating different activities and changes at the same time or in sequence of each other but in the private dwelling it is geared towards the interchangeability of activities between different rooms. This means that spatial organisations are different for both. For the public building it is achieved by providing generous dimensions and offering service rooms. For the private dwelling it is the relationship between the spaces. He gives the example;
"A spatial system in which different rooms can only be accessed through another room, for example the living room, is less capable of being adapted to suit different living patterns. The contrast here is with dwellings in which the spatial system allows every room to be reached from a central point or by a number of different routes"  .
Case Study on Building Order and Spatial Organisation:
Herman Hertzberger - Central Beheer Office Building, Apeldoorn, Holland with Lucas & Niemeijer 1968-72
Herberger designed the building under the principles of a building order and spatial grid. The building forms a sort of settlement of spatial units tied together to form a whole. The office building programs is of high diversity and each spatial unit (3m x3m) is accommodated within the grid. The brief called for a building that could accommodate spaces for specific function of the office workers but also allow constant changes to be accommodated without disrupting the rest of the building and maintaining equilibrium of use.
"The building has been designed as an ordered expanse, consisting of a basic structure which manifests itself as an essentially fixed and permanent zone throughout the building, and a complementary variable and interpretable zone" 
Each spatial unit is square in plan, with a cruciform transitional space which enters from the middle of each unit. Each unit also acts as an interpretable zone in which a series of primary building components can be inserted. They also can be rearranged or changed between each other. Through the combination of four units forms, a larger square unit creates an island with a cruciform transitional space dividing the smaller units from each other. Leupen states that over three decades of use the building has been able to accommodate all the changes in working methods and cultural trends  .
Building Adapting :
Joesph D Lewandowski describes how Walter Benjamin believed; Urform (archetype) was a practical way of being. Benjamin argued that the Urform of all dwelling is not for one to be in a fixed building, but more like being in a shell. He makes this distinction as he believed that in a shell the inhabitants can alter the space they inhabit  .
Laugier believed the primitive hut could be seen as the original archetype within the discipline of architecture. The hut for Laugier was based on a rational system of construction, i.e. a structural frame with a layer of protective covering. In his publication 'An Essay on Architecture' in 1753, he describes the assemblage by primitive man;
"Some fallen branches in the forest are the right material for his purpose; he chooses four of the strongest, raises them upright and arranges them in a square; across their top he lays four other branches; on these he hoists from two sides yet another row of branches; on these hoists from two sides yet another row of branches which, inclined towards each other, meet at their highest point. He then covers this kind of roof with leaves so closely packed that neither sun nor rain can penetrate. Thus man is housed" 
An archetype from Laugiers description of the primitive hut when interpreted with Benjamin's ideas can be deduced that within a shell of rationally constructed elements, inhabitants would be able to alter the space they inhabit for changing needs. An archetypal form is essentially a permanent framework in which inhabitants can take leave their mark.
Case Study of an Archetype - Dom-Ino House - Le Corbusier
The Dom-Ino house LeCorbusier had originally addressed the issues of his Dom-ino style of construction in 1915 for the reasons of exploring building production and how it could be applied to low cost housing. When the system was developed by Le Corbusier he combed the term domicile and innovation, domicile meaning a place that a person treats as their permanent home and innovation in terms of a new method. The essence of the dom-ino house was its light tectonic concrete frame consisting of square section reinforced concrete columns and cantilevered floor slabs. The system incorporated Le Corbusier's 'Plan Libre' or free plan technique which allowed the system to be flexible. Kenneth Frampton describes how the reinforced concrete framing could be readily filled in with masonry which essentially removed the necessary load bearing quality of the external envelope  .
Bernard Leupen describes how independence of the structure from its content such as its internal layout of spaces. The structure acts as the permanent element of the assemblage where the internal spaces are subdivided by non-load bearing walls. This allows them to change easily  .
Bernard Leupen describes how a building is composed of a series of layers. He argues that in principle each layer or combination of layers can be seen as the frame. The frame, in turn can be seen as a permanent part a building. Thus it can be concluded that each layer or combination of layers can generate freedom for other layers. He states that; "According to this principle, the permanent part of a building can be thought of as a frame which creates freedom and enables various adjustments to be precisely determined in advance. The frame is not just the permanent part of the building: it also embodies the buildings most important architectural and cultural values, which means that the building can react to changes in the requirements imposed on it over time without damaging its essential character"  . Leupen describes 'Generic Space' as the space defined by the frame that the changes take place in and describes that this space can be polyvalent (if there are no architectural elements and the dimensions invite different kinds of function) and it can be adaptable (contains elements that can be altered). He also describes how there are five layer in a building, structure, skin, scenery (international organisation), services and access.
Leupen believes a layer can become what he calls a frame by freeing another layer, e.g. the layer which it is framing . A 'framed layer' therefore can only change when it is disconnected from the layer that frames it. A simple example of this is, when the structure is based on a loadbearing framework and within it the non-loadbearing walls can be altered for their desired position at any time.
"Disconnection creates the conditions for freeing the content with regard to the frame and thus enabling the content to change through time. In this set-up the frame represents the enduring and permanent, and the content the changeable and fluid"
Articulating the frame can increase its autonomy. By expressing it architecturally, it will give the layer its own character. This can be applied to the permanent as its identity to those who perceive it.
Bernard Leupen describes how independence of the structure from its content such as its internal layout of spaces. The structure acts as the permanent element of the assemblage where the internal spaces are subdivided by non-load bearing walls theoretically allowing them to change easily  .