Commentary
Subject matter related to shear wall construction
Introduction
Some of the following comments first appeared in a letter our office sent to the editor of Fine Homebuilding magazine. A condensed version of the letter was published in issue #149 (September, 2002). The following is the full version of the original letter.
Thoughts from an Engineer
Our engineering office has designed structural systems or components for hundreds of houses. Of these, I can remember only one that was designed by an architect, and it was his own home. Many people buy "packaged plans" that they see advertized in the back of some home magazine. Typically you order a "plan book" (or now visit a web-site) and select a floor plan that you like. You can then order sets of drawings (or even "original" reproducible sets that allow you to run as many sets of blueprints as you want) to submit for a building permit and give to contractors for bidding.

We have dealt with many sets of packaged plans. As with anything else, the quality of packaged plans varies greatly--probably according to price. The following scenario is becoming too common: The owners have a parcel they want to build on. They find a floor plan that seems to fit their needs for space, room layout, orientation of view windows, access from their existing driveway to the garage, etc. They spend several hundred dollars on plans, and waltz into the building department expecting to get a permit. The building inspector reviews the plans, which always seem to come from out of state, and notes on the correction sheet for plans: "Need complete structural analysis, from roof to foundation." Outraged because they thought the plans should somehow entitle them to a building permit, the owners come into our office. We have to tell an already angry and disappointed couple that a complete structural analysis and resulting plans and details will cost them thousands of dollars and set their schedule back anywhere from four to ten weeks, depending on our workload.

Most packaged plans have a note somewhere (usually in fine print or off in a corner) that says something like, "the Contractor is responsible for complying with all local codes," or, "a local design professional should verify that these plans comply with local codes". This translates to "these plans may not actually be adequate to build a house in your area."

As for having a local design professional review the plans, licensing laws in California and probably most (if not all) other states prohibit architects and engineers from stamping and signing work that was not prepared under their direct supervision; the plans ask you to have a design professional break the law. We have too many people come in and say, "I just need you to stamp these plans". They seem to think that we will just open a drawer, pull out a stamp, stamp and sign their plans and send them on their merry way for ten or twenty dollars. We do not operate like a notaray public, who for a small fee checks your identification, logs your name in a record book, witnesses your signature and seals your document. Before we stamp your plans we have to apply considerable knowledge and skill obtained through many years of education and work experience. We are then responsible for that building for the rest of our lives.

Sometimes it appears that the designer spent more time rendering the front elevation of the house than considering how structural members align between floors. One particularly poor set of plans was originally drawn in the early 1990's. The 1994 Uniform Building Code made substantial revisions to wind and seismic bracing requirements. To meet these new regulations the designer ammended the plans by adding a detail that called for 2'-8" wide bracing walls at each corner of the building. Never mind the fact that 9 of the house's 26 corners had only two-foot wide walls shown on the original plans between the corners and the nearest window. The builder was expected to adjust the framing plan, electrical plan, window schedule and all the other building components that this change would affect. We have seen packaged designs that could not be built as they were drawn (roof trusses conflicted with coffered ceilings), did not meet the current building code, called for expensive stone veneer where it would have been concealed under a deck, used framing terminology that nobody in our area understands, and required material that is not available this side of the Mississippi, to mention a few problems.
Things to Consider
Some things to consider before buying a set of drawings from a plan book:
  • Is the design firm in your area?
    Building techniques and customs vary widely across the country. If you buy plans from several states away, the builders in your area may need to alter their methods to match the plans or deviate from the plans to suit their way of building. The former case increases building costs; the latter may also increase costs, and sends up a red flag for the building inspector.
  • Will your local building department accept plans from another state or region?
    Call them--if they even hint that they may require engineering, call a local engineer and see how they feel about engineering someone else's fantasy. We typically will take the floor plan and elevations and completely redraw the plans to show details that local contractors know how to build, using materials that they can get locally. This costs thousands of dollars, which you might otherwise pay a local architect to get one of his or her existing designs.
  • Do the plans conform to the current building code used in your area?
    Differenet localities often have their own particular requirements for information shown on plans. These vary from how you note smoke detectors and temperature-pressure relief valves on water heaters to requiring systems that would drain propane gas out of confined areas if a heating appliance should leak to mandating specific insulation and energy conservation measures.
  • Does the design account for local climate conditions?
    (See above--plans from the South typically do not consider snow loads that you will encounter in mountainous regions; likewise a design from the west coast would probably not meet construction requirements in hurricane-prone areas.)
  • Will your building department let you deviate from the plans without getting the changes approved (either by a local designer or the original plan provider)?
    We have yet to see a set of plans followed exactly. Owners almost universally want to change something; add a door to the garage, change the roofline, put in a wine cellar or the like. Even changes that appear "non-structural" may significantly affect the wind and earthquake resistance of a house.
  • If you order reversed ("flopped", or mirror-image) plans, will the printing also be reversed?
    When plans were drawn with pencil or ink on vellum, you could reverse them just by turning the original upside down when you ran it through the blueprint machine. This gave you copies that were completely reversed, including the lettering. Our building department expects to read the plans without looking at them in a mirror; they also will not accept plans just noted as "reversed".
  • Has the particular design that you want ever been built?
    The designer of one house acknowledged that the particular plan variation our client was building had never been built before. Maybe that's why the designer never noticed that the roof trusses would have punched through the coffered ceiling in the formal dining room. For a locally produced design you might even have the same contractor that built the "original" house build your version of it. Having a builder who learned all the design quirks while building someone else's house could be extremely beneficial.
  • Does the firm selling the plans have licensed professionals who can assure that the plans meet the current building code used in your area?
    This design professional would need to have a license to practice in your state and would need to stamp and sign your plans. However, an east coast engineer who happens to have a license from a west coast state (or vice versa) will still not account for differences in building methods from one area to another. Perhaps the firm could recommend someone licensed in your state who has seen the firm's plans before.
  • Would the design firm provide you with electronic (CAD) drawing files?
    This could provide you with a basis for adjusting the plans to your (and your building department's) liking. However, do not think that a local CAD user will simply download your house design and begin modifying it. CAD drawings are poorly standardized. It could take hours for a CAD expert just to print your drawings so everything shows properly.
Note that there may be packaged plans out there that meet these conditions. The plans that are satisfactory pass the plan-check at the building department and are not passed on to us-- we only see the plans that are deficient. Still, we suggest that people seeking plans find a designer in the area where they will be build their house, whether the designer sells plans out of a plan book, is a local contractor or home designer, or a licensed architect.