In his book Architecture depends, Jeremy Till, defines the ideal space in architecture as slack space, a space which "enables a broader range of behaviour to be", "is open to changing use", a space that inherently welcomes a broader diversity. This space can be found in the rooms of Georgian buildings for example where their dimensions have allowed a multitude of use over time.
He opposes this to hard space, the space of functionnalism, a space which is designed to be the smallest that can fullfill one idealised family unit. Hard space is the space that surrounds us in contemporary Britain; it is the space of most new private development where a kitchen is solely a laboratory for cooking in, where a bedroom barely fit a bed which can only be in one direction. Hard space is a prison.
Slack space, importantly, "does not dismiss out of hand the need for common ground", what it focuses on is to give flexibility and a sense of ambiguity on how the space is used; it welcomes a broader range of inhabitants.
There are two examples of extreme slack space architects whose work is redefining how we might look at social housing provision. One, Anne Lacaton & Philippe Vassal is a french practice, the other, Elemental, is Chilean.
Despite their radically different context, the parallels are numerous.
Their aim is to provide the maximum possible slack by building the maximum amount of space.
To do this, they use the budget in a similar way: they use a minimum level of fittings and finishes and use the most economical construction systems to produce the maximum amount of space. They often leave areas unfinished for the inhabitant to complete. They don't provide the minimum of space as the functionnalists do, but the minimum of finishes and fittings. They also both use prefabricated concrete systems to reduce costs.
Where their technique differs is to how this hyper slack space is provided.
Lacaton Vassal focus most of their project on the provision of substantial winter gardens, spaces weather tight but unheated and non insulated. A perfect example of this is the social housing scheme in Mulhouse. They are spaces that the inhabitant can use as a garden in the winter or as a room in spring and summer during the day. The space can be used in varieties of ways including building extra insulated accomodation inside. It is also worth noting that even the heated part of the houses or flats are generous.
Elemental's appraoch is to provide an external space which orginally is a terrace but that the inhabitants can build in to extend their home. Usually arranged as a terrace formed of two layers of duplexes.
The differences of approach can be understood in terms of the difference of climates. Indeed a large terrace in france is not usuable for a large part of the year.
Both architects accept that they don't have control on the future of their buildings, they actually encourage the inhabitants to take over, they leave things for them to do, they let things open. This combination of the architect as an enabler more than an author and the inhabitant involved in the design and making of the building (as opposed to a sole consummer) is a radical re-interpretation of the way we procure buildings.
This results in an architecture which can look rough but the generosity of the buildings, the quality of life that its inhabitants can enjoy compared to the alternatives are true luxuries. Who could argues that having half more or at times twice the amount of space to live in is not worth it?