“Loose fit” has recently gained prominence as a principle of environmentally-responsible architecture, but it is neither a new idea nor a new term. It was first used by the British architect John Weeks in the early 1960’s, who developed the Duffle Coat Theory of space planning.


“In order to get maximum flexibility within a (hospital) department it is necessary to provide rooms which fit around the activities which are to be carried out in them like a duffle coat.  The duffle coat, provided by the Navy for its officers, was not a tailor-made garment.  A few sizes were made and these were related to the known sizes of sailors so that it was usually possible to find one that would fit reasonably, and keep the sailor quite snug.”


Connecting this theory to hospitals and their endless need for interchangeability of hospital rooms, researchers discovered that between 50-65% of rooms in hospitals were less than 200 SF (19m2) in area, and most between 100-150 SF.  Weeks contended that the “research therefore suggested that if the number of room sizes used in a building could be reduced, by compromising the functions slightly – some functions would take place in areas slightly too small, while others would have a little too much space – then the interchangeability of functions between rooms would be increased.”


Interchangeability, the flexibility to easily reprogram a space designed for one function with a different one, provides economy. A building type in constant use and constant flux must remain responsive to the needs of users, so it is useful to have a standardized set of rooms that may be used for different functions.  In the example of a hospital, a 150 SF room may allow patient examination, storage, a doctor’s office, a waiting area, or a host of other functions depending on the space’s proximity to essential equipment.  The economy is therefore long-term, with fewer renovations necessary for the accommodation of the various uses that might be necessary over the life of a structure.


In contrast, austerity offers immediate results.  Building a tightly tailored skin around a particular function reduces waste in construction, and in the continuing operation – the supply of water and energy – necessary for occupancy.  But the long-term reusability of the space may prove limited.  Enshrining a single programmatic use in concrete, permanent and hard to modify, means that as time and technology changes, the structure resists efforts to claim it for a new use, to add on, or to introduce a new technology.


In 1971, Alex Gordon became President of RIBA with the mantra “Long Life, Loose Fit, Low Energy,” and the connection with sustainability was forged.  A tight-fit system has limited interchangeability, a loose-fit one allows the freedom to reconfigure at will.  It is the reason that many historic buildings are desirable for renovation; their high-ceilinged, generous spaces are convertible into housing, offices, and retail spaces.


“All buildings are predictions.  All predictions are wrong,” writes Stewart Brand in How Buildings Learn.  If all the spaces within a structure’s box are simple and repetitive, flexibility may be possible.  But is interchangeability a desirable parameter in making good architecture?  If designers instead prefer the particularity of space and orientation, aspect and access, how can loose fit be incorporated into the heroic geometries of idealized and organic forms, such as within Frank Gehry’s Brain Institute in Las Vegas?


The design of the center for neurological research has the requisite magic, a gala celebration of form in the playful wrapping of the large assembly space in an expendable skin of stainless steel. An equally iconic breezeway connects the fantasy hall to a modest and careful research center, comprising the bulk of the center… and the place where the patients are evaluated, research undertaken, business is completed.  The spaces in this structure, while not exactly identical, certainly offer the possibility of future interchangeability without compromising the intricacy and character of the building envelope.

“Architects are by training, aesthetics and psychological predisposition, narrowly committed to the design of big permanent single structures and their efforts are directed merely to focusing big permanent human values as unrepeatable works of art.”  Reyner Banham’s essay ‘Vehicles of Desire’ compared the form-making of architecture to the bodywork of streamlined vehicles. Both cars and constructions must serve a function or they shall be consigned to the scrapheap – an average vehicle in less than 12 years, a commercial office building in 25 years.  John Weeks’ influential work on loose fit wanted to extend that period of utility, but he also believed that aesthetic judgment should not be allowed to constrain internal function or processes.  As long as the building envelope remains a “loose fit” against the structure, perhaps it can accommodate a degree of iconicity as well.