12 April 2012

Not all details are equal

I recently followed this link in the NRCA SmartBrief: "Modular construction could boost efficiency of construction projects." It led to an article titled "Construction officials pushing prefab revival", which touts the advantages of modular construction. The opening paragraph acknowledges the "technique [is] hundreds of years old" but modular design may be a foreign concept today.

Modular dimensioning has been with us for a long time, and is almost inescapable for some things; masonry units are modular, and partitions rely on modular dimensions for framing and sheathing. And, although they're not modular in the same sense, many products at least come in standard sizes. In each case, the consistent properties make these products easier to know and to use.

The point of the article, however, is not modular material dimensions, but modularity on a larger scale - prefabrication of modules that will be assembled on site, reducing the on-site construction time. The benefits of off-site fabrication are well known; the controlled conditions improve quality control and provide a more consistent, reliable product or assembly.

Designers often spend an inordinate amount of time creating custom details. It often seems as if each building is the first building ever, with team members fighting each detail, trying to figure out what goes where and how it all goes together. What was learned on previous projects is forgotten, and everything is new - again.

That might make sense for some projects, where every detail is, indeed, special, and requires that level of attention. In most cases, for most projects, treating each detail as unique is a waste of the designer's time and a waste of the owner's money, as virtually no one will even notice those details, let alone appreciate how wonderful they are.

Many years ago, a wise senior architect told me we should do most of our work with a kit of parts, using tested and reliable standard details and products for most things, and giving special attention to those areas that really matter. More recently, another architect used the 80/20 analogy, saying we should spend 80 percent of our budget on the 20 percent of the project that will make an impression.

How much easier would it be if we used a set of standard column details, standard wall assemblies, and a standard set of products? What about standard bathrooms? Instead of trying to tuck them into odd, leftover spaces, and spending countless hours moving fixtures an inch, jogging the walls, and fighting for half an inch to accommodate ADA requirements, what would happen if we started with an efficient bathroom design, then adjusted the areas around it?

Going a step further, wouldn't it be easier to design at least large parts of buildings using prefabricated modules? A hotel or a hospital will have hundreds of identical rooms. Must each be built on-site as a custom room, or could they be mass-produced in a factory, then shipped to the site for final assembly?

In theory, it would be great fun to treat each square inch of a building as if it were the most important thing in the universe, and I understand the drive for perfection. That may be a stimulating exercise in design studio, but the real world has different values. Schools should teach not only the theory, but the practicality required for all but those rare projects that have an unlimited budget.

With our ever-shrinking schedules and increasing complexity of construction, using both modular design and standard details in most of the project will allow the designer to pay more attention to those parts of a project that make the most impact. I don't think I heard that in school.


  1. I don't think I heard any of this in school either. What I do recall, while I was still in school or soon thereafter, is Operation Breakthrough, a big HUD program to provide better housing for more US citizens. That got me interested in industrialized housing. Now, over 30 years later, the application of industry to housing does not look much different than it did then. Precut and modular homes are still being put up in the same way, and satisfying about the same market share at about the same percent savings over a comparable new "stick-built" dwelling. A few eccentrics buy small but upscale modulars assembled in boutique factories, but mostly for short-term use vacation dwellings. Very few think of a moduluar or pre-fab as their dream home.
    Why? Well, HUD wrote a 95 page report about it at http://www.gao.gov/products/PSAD-76-173.
    If you have not seen the video of the erection of two buildings by the Broad Corp. in China, for an eye opener about what prefab can do for commercial construction, have a look at www.youtube.com/watch?v=Ps0DSihggio, and www.youtube.com/watch?v=Hdpf-MQM9vY.
    Why doesn't this kind of thing happen in the US? For some ideas about the dampers to change in our domestic AECOO industry, see http://www.buildingproductmarketing.com/2012/04/why-building-products-fail-case-of.html and http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=107792735&gid=98421&commentID=76860201&trk=view_disc&ut=0XHHcRCKiZs5c1

  2. Louis Medcalf, FCSI, CCS18 April, 2012 08:49

    Back in the 1960s at the University of Cincinnati, there was a lot of interest in building modules, but I haven't been involved with any such projects until recently. Our firm has been working with Turner Construction on 3 hospital IPD projects that involve construction of patient toilet room modules off site. The fully plumbed and wired modules are trucked to the site, set with cranes, and final utility connections made. There was an article in BD&C a while back about our first venture into this area. This approach saves time, money, and results in better quality.

  3. Check out this article about the replacement hospital in Joplin, MO, that was built, using modules, in well less than a year. http://hosted.verticalresponse.com/1173031/2df0735892/545967183/532e2b179b/
    Aspen Street Architects is a long-time client of ours. They didn't seem to need our specifications services for this project (bummer)but we're proud of them for getting the job done. Now, it would be cool if this process could be used in California!