Why? – Plan Review

David R. Olson, PE

In today’s construction market, there is much variety between the levels of detail in construction documents prepared for building projects. Some projects have multiple sheets of detailed floor plans supplemented by pages of construction details, sections, risers and control diagrams. At the other end of the spectrum, some projects have very “thin” drawings indicating locations of major equipment, perhaps not even drawn to scale, with notation directing the contractor to field verify necessary connection points, with coordination with existing piping, ductwork, conduit and structure. Often, piping systems and even ductwork systems are left to the contractor to design.

Even the most thorough engineering efforts require a review by a third party code authority. It is very rare that a project is submitted that complies with all aspects of the governing codes. Sometimes there are simple problems of indicating trap primers or cleanouts on the plumbing drawings – or perhaps the location and access to water hammer arrestors. Within duct systems, often times the means to balance the system is not detailed, and the necessary outdoor air ventilation quantities are not defined. If the third party plans examiner does not comment on these items, chances are very good that they will not be included within the project at completion.

For instance, some written specifications direct the contractor to install cleanouts as required by code, even if they are not shown on the plans. This is not fair to the bidding contractors who are in a competitive bid situation. The code requires cleanouts at a multitude of locations within the plumbing sanitary waste and vent system. If one contractor includes all cleanouts that he determines are necessary, and his competitor only includes the cleanouts shown on the drawings, then he is at a competitive disadvantage. The building owner will suffer down the road if required cleanouts are not installed and they encounter a blockage within the sewer or vent system.

I have heard, “it passed inspection – the inspector looked at this and he was fine with it” more times than I can remember. The codes are written to promote a minimum level of construction quality and occupant safety. When codes are read by a user, there is a certain degree of experience necessary to interpret the intent of particular sections. The inspector cannot be expected to physically observe every part of the installed construction. Sometimes, an inspector is in a hurry and does not have time to thoroughly inspect every installation. Other inspectors may not understand the significance of a part of an installed system, thus they overlook violations. Still other times, the inspector comes onto the site, witnesses a number of code violations and directs the contractor to correct these offenses and reschedule a re-inspection. When the inspector returns, he looks quickly at two or three of the earlier violations and is satisfied that the contractor has performed diligently. The failure of an inspector to identify a code violation in the field does not render an installation code compliant. The owner may be required to correct violations during future remodels or subsequent inspections.

The International Code Council publishes a complementary package of Code Commentary volumes. These are very useful for understanding the intent of a requirement, and often they include diagrams and photographs to illustrate the correct and incorrect methods to achieve code compliance. When in doubt over the meaning of a code section, turn to these manuals and you will often find some language that will help you understand the intent of a code section.

Third party plan review is performed by the code authority as a courtesy to its patrons. Not every building department budgets money to allow performance of these reviews. I believe that it is much more effective to review plans and specifications prior to granting a building permit, than to identify code violations once a building is under construction. It is always less expensive to do it right the first time. The codes are updated on a three year cycle. Usually there are subtle items in each code cycle that modify a construction method that “has always been done this way.” That’s progress. A good plans examiner is aware of these items and can help avoid unnecessary expense correcting code violations discovered in the field later.

During my design days I was often wary when I received a plans examination notice back from a building department. At times it was hard to accept that my plans were unclear or had violations of code indicated. The codes are a complex set of rules and regulations, and it is very difficult to know all the elements of compliance – particularly when considering parts of construction designed by other disciplines, such as fire separations and smoke barriers. However, I was always grateful when I saw some non-intended code violation that this process was able to avert. Yes, changes had to be made to the drawings, but in the end we had a tighter set of documents for the contractor to build from. The plan review process leads to better buildings and safer construction.

As part of my consulting practice, I perform mechanical plan review services and am registered as an ICC certified mechanical and plumbing plans examiner. I was required to pass an examination to achieve this certification. I review plans for 50 – 100 projects in a typical year. Some are large and complicated; others are smaller and simpler buildings with more common systems. I would suggest that after doing this work for 20+ years, less than 10% of the projects I review result in the statement, “No Comments Noted” – although it does happen occasionally. Many of the comments included within my reviews tend to be repetitious. If a code violation is made on one floor level, chances are it will be repeated on multiple levels of a multi-story building. Most violations are quite subtle, and I think that most designers do not suggest violations within their documents intentionally.

When I first started performing plans examinations for various building departments and third party code review organizations, I had to learn to differentiate between “Plan Review” and “Peer Review”. There have been numerous times that I have reviewed a set of drawings and thought that the mechanical system being proposed just won’t work. Yet, there is nothing wrong with the design from a building code standpoint. Other times I see plans that have been designed well above the minimum criteria of the code. This is not a violation of code – the code is a minimum level of performance. A building code plans examiner is just looking at code items – not critiquing a system design.

If you are preparing construction documents and are uncertain of a code sections meaning or intent, pick up the phone and call your building official. They are happy to explain their interpretation of a code section. If it is a very complicated question, they may appeal to the ICC for a formal code interpretation on your behalf. Ultimately, this individual will be responsible for approving your design prior to issuing a permit. You have nothing to lose by asking the code official to provide their feedback during the design phase of your project.