When a structural design needs a peer review in Florida

Why a design gets a second engineer’s read

A structural design is checked by the team that produced it, and by the building department before the permit. A peer review adds a reader from outside the design team, with no stake in its choices, who follows how the structure carries its loads down to the ground.

The value is in the timing: a mistake found on the drawings is settled with an answer and a corrected sheet, while the same mistake found on site can mean shoring, a field repair and lost weeks. A building official can make the review a condition of the permit; an owner, a lender or the design team itself can also ask for one.

Where a building official requires one

Florida’s statute on building permits never mentions peer review. The requirements listed below come from local building departments, each one a condition of the permits that department issues, with criteria of its own, so the same design can need a review in one city and not in the next.

No county-wide requirement was found in Broward when this guide was written, so there the office that will issue the permit has the answer: ask it directly. The same goes for any place this guide does not name, and anywhere in the state the owner, the lender or the insurer may still ask for a review.

• Miami-Dade County, on the buildings it permits in its unincorporated area: ten stories or one hundred feet, whichever comes first; essential facilities that are not low-rise; half a million square feet or more on any single story; and more than three stories where the wind-resisting system is light-gauge steel or wood.
• The City of Miami: residential and commercial buildings above three stories, or above fifty feet in height; essential facilities; more than a quarter of a million square feet of floor area in all; and buildings whose floors and walls are framed in light-gauge steel.
• Coral Gables: threshold buildings, as state law defines them; essential facilities; slender buildings, with an aspect ratio of seven or more; buildings of more than a million square feet; any element that supports, in total, more than fifteen percent of the building’s area; and designs that rely on nonlinear or progressive-loading analysis.
• In all three, the building official can also require one for a project outside these lists, such as an unusual or complex structure.

What the reviewer checks and hands back

The reviewer reads the drawings and calculations against the code that governs the project, and runs independent calculations on a representative part of the structure. Coral Gables writes that method into its rules, and gives the reviewer the designer’s own calculations for reference only.

What comes back is a review report with a log of comments, ranked by weight, each naming the sheet, the concern and its consequence for the structure. The design team answers, the reviewer reads each answer, and a comment closes only once it is settled.

The review does not redesign the building. The engineer of record keeps sole responsibility for the design; the reviewer gives an independent opinion on it.

• The loads and the load path, from the roof to the foundations.
• The analysis model and the assumptions behind it.
• Details and connections, and whether they can be built as drawn.

When to start, and what to send

Start once the structural system is settled and before the set goes in for permit. Miami-Dade County wants the comments resolved before the permit application is submitted, so a review started late holds up the submittal itself.

The drawings and calculations are enough for us to start. We check whether the office that will issue the permit asks for a review, and under which of its criteria, and then send a proposal sized to the review the project needs.

• The structural drawings, in their latest issue.
• The calculations, and the analysis model if there is one.
• The geotechnical report, for the foundations.
• The address, and the date the set should go in for permit.

What owners and design teams ask about it