A builder of stabilized compressed earth block buildings tells his students that such buildings will last 2000 years. A designer/builder trained in Europe notes that houses in Germany with 100 year mortgages are meant to last for centuries. Many green and natural builders strive to make homes that will stand for generations and look with dismay on the homes that dominate our cities and suburbs which have an estimated life span of perhaps fifty years or less.
But an element of home design that is almost always overlooked to one extent or another even by green builders is “Open Building” which is necessary to make a structure last and stay useful for one generation or several, hundreds of years or a millennium or two.
“Open Building” as it applies to single family homes means, in part, that the systems of the building are kept from tangling with each other and are easily accessible without destruction to other systems so that they can be replaced and reconfigured as they age, as the needs of the occupants change and as technology advances.
Even in green built buildings wire is buried inside walls. A metal conduit in an compressed earth block wall won’t last the 2000 years the wall may last. Water and waste pipes hidden are not likely to last 50 years.
“Open Building” has been applied for a number of years in large apartment blocks in countries around the world. As described by Stephen H. Kendall and Jonathan Teicher in “Residential Open Building” (available to many as an e-book through NetLibrary and in a limited form from Google book search), the word “support” means the support systems of the individual apartment: HVAC, Electrical, Water, Waste, Natural Gas. The word “infill” refers to finish-out of the individual apartment.
Tedd Benson, founder of Bensonwood Homes, a pioneer of residential open building for single family homes in the United States refers to the infill and support as “layers”. Layers include: Structure (the load bearing walls or framing), Skin (the siding, windows, roofing and insulation), the Space Plan (interior wall configuration and the size, number and use of rooms), Plumbing, HVAC, Electrical and Stuff (the furnishing). Some layers are longer lasting than others. Some need to be updated or repaired more frequently than others but no layer remains unchanged forever, nor is any layer likely not to need to be repaired.
In the USA we are most familiar with something similar to “Open Building” in commercial office buildings and retail centers in which the builder provides an enclosed space with access to the HVAC, adequate electrical lines and waste pipes and so forth while, the lessee hires contractors to finish out the space to their specifications. When a tenant leaves, the new tenant may retain all or part of the finish out, or they may strip down the space completely and start fresh.
Although a great deal of unsustainable waste is generated by this frequent reconfiguring and redecorating to suit the whims and egos of corporate officers, the fact that the spaces can be completely reconfigured without destruction of the entire building is an advantage in sustainability.
An “Open Building” commercial space goes far beyond the standard American commercial model though. “Open Building” buildings and spaces are designed so that each of the support systems could be replaced and updated without affecting the other systems. Without open building we see commercial building after commercial building razed and sent to the landfill, a process that is certainly not sustainable.
In “Open building” apartment blocks, the lessees or purchasers of the individual apartments are enabled to configure their apartment in ways that meet their needs and desires. This reduces alienation, improves the well being of residents and increases their ability to live as they choose rather than being locked into a master design. This process would particularly lend itself to American co-housing developments.
An “Open Building” single family home can serve for generations and in the vision of Stewart Brand, learn. When family needs change or when the neighborhood changes from suburban to urban, from residential to office and back again, the internal walls of the building can be reconfigured without affecting the integrity of the structure.
An “Open Building” building from 1860 (if there were such a building) though it were built in the days of oil lamps and coal or wood cooking would have seamlessly allowed for the introduction of gas lighting and cooking to be followed by knob and tube wiring to be followed (unfortunately) by aluminum wiring, which would in turn be replaced by romex, updated by various fire preventing code improvements and which will no doubt be replaced in coming decades by some other advance in technology.
Think of all the changes in HVAC and plumbing that have taken place in the last 150 years, and think of the expense involved in incorporating them into existing buildings. Even within the last 20 years our ideas about windows, electricity, ventilation, air conditioning, plumbing and the needed amounts of electricity of have changed substantially,
Yet how very difficult these improvements are to incorporate into our existing homes. How much expense beyond the new systems themselves goes into installing them in our homes whether the house is 50 years or 10 years old. In an “Open Building” home the expenses for renewing worn systems or updating obsolete ones are minimized.
Some aspects of open building for single family homes are simple to envision: accessible chases for water, HVAC and electricity and data so that each system can be replaced, repaired or altered. But other aspects of open building are more subtle.
Tedd Benson suggests “plug and play” electrical connections, crimped copper plumbing unions, quick connect manifold valves and compatible interchangeable house parts. He points out the advantages of timber framing (which his company uses) for open design, though the framing is only part of the open building design they follow.
You can learn more about open building at http://bensonwood.com/innovation/. There’s an excellent story from the October/November 2006 Fine Homebuilding entitled “Reinventing the House” by Andrew Dey. You may be able to find it on the web or if you subscribe to the magazine you can have access via Finehomebuilding.com.
Stewart Brand’s book, How Buildings Learn, served as an inspiration to Tedd Benson and convincingly shows that houses are not static structures. Mr Brand did a BBC Series based on his book and has now made it viewable on Google Video.
Though its subject is open built mass residential housing, Residential Open Building by Stephen Kendall and Jonathan Teicher has valuable background on the bigger picture and philosophy of open building.
Bensonwood Homes’ white paper “What is Open Building” may be found on their site and downloaded. It makes the case for open building and shows they have registered "Open-Built" as a servicemark which is why the less attractive term “Open Building” has been used throughout this essay. Open-building.org has a number of resources available, though their emphasis is mass housing development rather than single family homes.
Perhaps in the future sustainable open building will be the norm, reconfiguring and updating our support systems will be simple and our homes can last (with periodic renewals) for centuries. But for now it is up to the individual contractor, designer, architect and homeowners to seek out information on open building and advocate that the evolving concepts of it be incorporated into the structures, much as they have made the case for other aspects of green and sustainable construction.
Below is part 1 of Stewart Brand's BBC program, "How Buildings Learn" directed by James Muncie with music by Brian Eno.