Thursday, July 7, 2011

Conventional Construction: One More Term

I should mention one other important term - approved. It’s a term you often hear, but it has many different meanings, depending on what’s being approved and who’s doing the approving. Our favorite, as designers and builders, is the one that appears on that long-awaited letter from the Planning Department – ‘all agencies have approved your building permit application’. Two slightly different meanings are also important in project design and construction.

Pre-approved

A material or method not normally considered conventional may be used prescriptively (without further analysis) if it is pre-approved. The pre-approval process involves extensive testing by a testing lab, which must itself be pre-approved by the ICC. The lab then prepares a report describing the approved uses of the product tested. A familiar example of a testing lab is the Underwriters Laboratory (UL). For conventional construction, the ICC Evaluation Service (ES) is probably the most important. Metal framing connectors, engineered wood products and gravity retaining wall systems are examples of products that are pre-engineered and pre-approved.

Reviewed and approved

Everything on a set of plans and everything built from those plans must be reviewed and approved by one or more representatives of the local authority. Also, despite the complexity of building codes, local regulations and all the other hoops that must be jumped through to get a building permit, there are still gray areas not clearly defined and/or understood. When these situations arise, the local Building Plans Examiner, Building Official or Building Inspector must review the proposed solution and decide whether or not to approve it.

For the project designer, the big hurdle is getting that approval letter so the contractor can begin work. For the contractor, there’s always the fear that the Building Inspector will look at your ‘conventional’ work and say ‘you can’t do that’ or 'that's not on the plans' - and his word is the final word. However, a thorough understanding of the rules will often allow a designer or contractor to convince the inspector to see things your way. Don’t relax yet, though – especially if you get a different inspector for the next visit (when scheduling an inspection, always make sure your regular inspector is not sick or on vacation). The project team can’t really breathe a collective sigh of relief until that final permit sign-off.