We track our multifamily project permit timelines in a spreadsheet. The dataset isn't huge — 30 projects across 18 months in Phoenix, Las Vegas, Cleveland, and Austin — but it's consistent enough that one pattern jumps out.
Four-story residential buildings permit in 64 days on average. Five-story residential buildings permit in 102 days on average. Same metros. Same building type, broadly. Same drafter (us). The 38-day difference isn't random.
I''ve started calling it the *mid-rise penalty.* It's structural — built into the IBC — and it's predictable. Here's where the 38 days come from.
The IBC line that drives everything
International Building Code Table 504.4 sets the maximum height for residential occupancy by construction type. The relevant rows for typical multifamily:
- Type V-A construction (combustible/wood frame, with fire-resistive rating): 70 ft / 4 stories above grade for R-1 or R-2 occupancy. With NFPA-13 sprinklers, can extend to 5 stories at 70 ft.
- Type III-A construction (combustible/wood frame above non-combustible podium): 85 ft / 5 stories. With sprinklers, up to 6 stories.
- Type II-A construction (non-combustible/steel/CMU): 85 ft / 6 stories.
The cost difference between Type V-A and Type III-A is substantial — Type III-A requires a non-combustible podium for the bottom story (typically concrete or CMU), which adds $15-$30 per square foot of podium area. So the financial pressure on developers is to maximize Type V-A height. Specifically, to push 4 stories of wood-frame to 5 stories of wood-frame whenever the project economics allow.
Where 5 stories breaks the easy review path
At 4 stories of Type V-A, the building is in the heart of what the IBC and most plan-checkers handle as routine wood-frame multifamily. Reviewers see 4-over-podium projects every week. The plan-check workflow is well-established.
At 5 stories of Type V-A, the building is on the edge — at the very top of what the IBC allows for that construction type. The reviewer's checklist gets longer, the structural review goes deeper, and the questions multiply. Specifically:
- Sprinkler system review: NFPA 13 vs. 13R systems get scrutinized harder. Some jurisdictions require NFPA 13 (full coverage) at 5 stories where 13R was acceptable at 4. Sprinkler engineer needs to clarify.
- Structural calculations: shear-wall analysis at 5 stories of stacked wood frame is more sensitive than at 4. Reviewers ask for more drift calculations, more anchorage details, more diaphragm-to-shear-wall connections.
- Egress and accessibility: the IBC has stricter egress requirements at 5 stories — second exit-stair locations, smoke-control systems, area-of-refuge details. None of these apply at 4.
- Fire-resistive separations: at 5 stories of Type V-A, fire-resistive ratings get tighter, especially around the lowest residential level above the parking podium. Reviewers want to see UL-listed assemblies on every separating wall.
- Energy and sound: cumulative dead loads on the floor diaphragms increase at 5 stories, which means floor-and-ceiling assemblies have to be re-evaluated for sound transmission and fire rating. Often triggers an additional engineering review pass.
Each item on that list adds 2-7 days to plan-check time on average. Cumulatively, they're the 38-day difference.
The rare cases where it's faster
Two scenarios where 5-story Type V-A actually permits as fast as 4-story:
First, in cities that have lots of recent 5-story Type V-A inventory. Cleveland, for example. There's been enough 4-over-1 development in Tremont and Ohio City over the past 5 years that plan-checkers are familiar with the format. The questions don't pile up the same way they do in cities seeing 5-story Type V-A for the first time.
Second, when the project explicitly designs to NFPA 13 (full coverage) from day one. Skipping the NFPA 13 vs. 13R debate eliminates 8-12 days of back-and-forth. Costs more in sprinkler design but compensates in permit time.
What we tell developer clients
Three things:
- If your project economics work at 4 stories, build 4 stories. The 38-day permit savings often outweigh the per-unit revenue loss from one less story, especially when carrying interest is high.
- If you must build 5 stories of Type V-A, design to NFPA 13, plan for area-of-refuge and second-stair details up front, and budget 100+ days for permit. Don't fight the timeline; price it correctly.
- If your AHJ doesn't see 5-story Type V-A often (Phoenix DSD didn't, until about 2022), expect more questions than the Cleveland or Seattle data would predict. Familiarity matters.
Adding a 5th wood-frame story to a multifamily project doesn't just cost more in construction — it costs 6 weeks of extra permitting, every time. Price it into your underwriting before you commit to the height.
The 30-project dataset is big enough that I'm confident in the 38-day average. Variance is high (some 5-story projects clear in 75 days, some take 130) but the median is consistently above 90. We're going to keep tracking it. If anyone wants the spreadsheet, send an email.