Adaptive Reuse1

No matter how generic you design a building, it will almost certainly get remodeled at some point during its lifetime, and in many cases it will be remodeled more than once (beyond just the painting and wallpaper type things).  Partly this is due to the fact that the average person only lives in a house for seven years, and partly because both technology and a persons life situation changes, each providing different motivation to remodel.  Adaptive reuse is about making a building that accommodates  the kind of changes people are likely to make over the lifetime of the building.

As a culture, we're not much for planning for the future, and with buildings whose lifetime is (hopefully) at least fifty years, the problem is all the more difficult, because it is difficult to know what future needs will be.  Based on experience remodeling existing building, there are a few conclusions that can be drawn.

A quality house will always be more desirable than one build shoddily, even if the construction doesn't meet today's standards.  When it comes to using structural materials, it doesn't pay to skimp, as over time houses have a tendency to sag.  It does not seem likely that energy will ever be so abundant and cheap that being as energy efficient as possibly won't always make sense.  Features of houses that are the "latest rage" tend to get eliminated in some way in the future.  Houses that "feel" good to one generation are likely to be equally well received by successive ones, but the specific uses of the rooms is likely to change.  Of all the aspects of a house, utilities are the ones that change the most, especially electric & electronics.

There are a number of levels of reuse, each using successively more of the existing building.

At the lowest level, the existing foundation and main floor platform can be reused, but nothing else is worth saving.  Sometimes even this level can be due not cost effective, since it is generally cheaper and easier to build new than mess with an existing building.  

The next level is to reuse the shell of an existing building, redoing the interior partitions and utilities.  Since the shell is typically only about 25% of the total cost, there must be significant motivation to reuse it: either it has to be of significant architectural interest to make someone want to save it, or be close enough to the current construction quality that it can be used as is.  The main concern here is load bearing walls, since they can't moved without providing an alternative means of support.  While its generally straightforward to create reasonable size openings (say 8-10'), the larger the opening, the bigger the replacement support beam is, and hence the more difficult and expensive the modification is.  Since at least two exterior walls always carry some load,  dramatic changes in the size of window & door opening present similar problems.

The next level is to reuse the rooms more or less as they are, and make mostly cosmetic changes, as well as updating utilities, with electrical upgrades being the most common.  Bedroom may become offices, kitchens and bathrooms often get updated, but most of the house is left intact.  When a house has a good layout, people find clever ways of adapting room to the current needs.  When a house can easily be expanded by adding a second floor or a wing, it is easier to reuse.  Likewise, if an existing second floor or basement can become a separate residence, the house can be adapted in that way also.

Reuse at is best involves little changes other than decoration, although utilities are a constant problem.  The most volatile aspect of this is the electric wiring for electronic devices: telephones, cable TV, alarm systems and  computer networking.  Although often have too few circuits, not enough telephone jacks and no internet or cable TV jacks, most people find ways around all these things, especially since upgrading them usually requires breaking open walls, fishing wires thru them, and patching them back up.  A better choice would be to install an adaptable wiring system, but other than wire-mold which is often used in commercial buildings, or exposed conduit (often used in older masonry structures in Europe) there are not many options.  Individuals have created systems of chases that are hidden behind baseboards, door casings or other decorative features that can be attached via screws so that access to the wiring is easy.

The ideal building system from the reuse point of view would be one of standardized components that simply bolts together, but since there are no such systems available, the next best thing is to make the building be a reasonably high quality.  In the case of interior partitions, office building already are made of  modular or easily modified components, but there is little motivation to do so in residential construction.  Simple layouts that take into account many of the design patterns are more likely to get reused.  The less complex the structure is (and hence the smaller number of load bearing walls), the easier it is to move interior walls around.  Utility upgrades can best be accommodated if they are not a integral part of the building and can easily be accessed to change them.  Open web floor trusses can make laying wiring, plumbing and ductwork easier, and creating access doors makes it even easier yet.  Creating utility chases is another way to give easy access. 

Experience indicates that the buildings most likely to be reused are those at the far ends of the spectrum: very cheap ones, because they're easy to remodel, and one with a high level of craftsmanship and a good design, because people value quality.


How Buildings Learn, Steward Brand

Adaptable Reuse, Environmental Building News, V12 #2 Feb 2003 example of an adaptable timber frame system.  article from Fine Homebuilding Oct 2006 on adaptable building


1:  the background for this is from "How Buildings Learn", Steward Brand.