Structural Plan Review

One of the inconsistencies in the code world is that several items require verification but not everyone follows a pattern or path coinciding with other reviewers. Some work from the ground up and some work from the roof down. Some work in a clockwise motion and some work counterclockwise.

I believe this is a component to plan review that is intimidating to some, especially those newer to the role and we have new people coming into the code world every day. I know when I jumped into plan review, it was intimidating but this slowly went away as my skills strengthened.

Furthermore, some jurisdictions accept structural calculations stamped by an engineer without looking through them and, from experience, I highly encourage reviewing this information. Had I not reviewed this information for various projects during review I would have missed a lot of important items that needed to be corrected by the engineer. I would have overlooked issues such as:

• the wrong engineering entirely being submitted (not easy to explain why you approved the wrong calcs for a project to go out the door)
• engineering that is not legible
• incorrect loading info
• missing point loads in beam calculations
• Missing overturning calculations (we see this a lot) or inadequate hold-downs
• shearwalls shown that weren’t on the plans, etc.

Most engineer’s I have spoken to view us as another pair of eyes and they appreciate that we go through this information. They are human and make errors just like everybody else. The conundrum is knowing and understanding the level of review appropriate and not appropriate. We must remember that this information is from professional and structural engineers so it’s about finding that balance of code review without infringing on the licensing they worked hard to obtain.

To help, I thought I’d share my process for conducting structural reviews for a new home constructed of wood elements and designed using structural analysis, as that is what we see frequently due to our seismic design category (these are general guidelines):

First, I conduct a general review without even looking at the plan requirements, in depth. I scan through the plan set looking for “code 101” items. Examples are:

• incorrect code/ standard being noted, or missing entirely
• outdated code sections/info in boilerplate information
• items that aren’t legible

Second, I verify the design data is correct and, if it is repeated on the plans, that it coincides with the structural calculations. This entails looking at snow load, lateral load and wind load data coefficients to assure they are as required in Chapter 16 of the IBC or the ASCE7 (remember, these are engineered designs so most if not all requirements run through IRC Section R301.1.3 and push the design into the IBC).

Third, I review the geotechnical information (if it was required) to assure the soil design data in the structural calculations coincides with the geotechnical information. At a minimum, I verify there’s a presumptive load indicated.

Fourth, from the roof down (in a clockwise manner), I verify all gravity load supporting elements, through floors and down to soil in the structural calculations.

• This starts with using the snapshot feature in Bluebeam of the roof framing that I then lay over the floor below to assure point loads are picked up (transfer paper can also be used if you don’t use electronic review means).I follow this process for each floor down to the foundation.
• While following the item above, I move forward verifying beam type/species and size, lengths of each beam and header on the plans are correct, bearing of beams/headers, checking loads imposed on the beams and headers, post/beam connections and post to footing connections (if not within a wall).
• Lastly, I verify footing location, size, depth, and distance from slopes are adequate for the imposed loads from above.

Fifth, I go over lateral design requirements. This is where I verify:

• there’s a shearwall schedule
• shearwall aspect ratios, locations, heights, lengths, and types to assure the calculations meet the SDPWS and that this information is legibly relayed onto the plan set.
• the floor and roof diaphragms to assure they meet aspect ratio requirements, if any blocked diaphragms are needed, as well as shear transfer elements through floors.
• every single detail on the plans to assure all information is clear and dimensions, framing clips, connections, etc, aren’t missing or incorrect.

What you should take away from this is that we do not double check all of the calculations or at least I don’t believe that is a charge of ours. We look at what goes into the calculations and the end results; is the easiest way to explain it. Once we have, basically vetted the structural information, we then assure these requirements are depicted on the plan set.

Hopefully, this will help some people newer to plan review grasp structural review more easily and if you see something I missed, I’m always looking to improve how I do things; please share.