Research study
How much American housing sits in a wind-borne debris region
One hurricane boundary follows county lines, so Census data counts it exactly. The other is a one-mile coastal band that county data cannot count.
Written by HyreGarage Research Desk Primary-source research and data analysis
Audited by HyreGarage Research Desk Citation, computation and retrieval-date audit
The finding
1,948,542 housing units sit in Florida’s High-Velocity Hurricane Zone (HVHZ), which is exactly Miami-Dade and Broward Counties.
That is 19.3% of Florida’s 10,082,356 housing units, in 2 of 67 counties (Census ACS 2023, table B25001, retrieved 2026-09-06).
The wider wind-borne debris region, a one-mile coastal band under ASCE 7, cannot be counted from county data.
What did we find?
Florida Building Code Section 1620.2 names Miami-Dade and Broward directly, with requirements up to 186 mph in Miami-Dade. Because the line follows county limits, not distance from the shore, Census counts answer the question exactly.
That is 1,085,414 in Miami-Dade and 863,128 in Broward: 19.3% of Florida’s 10,082,356 housing units, in 2 of the state’s 67 counties.
Palm Beach County, next to Broward with 713,855 housing units, is not in the HVHZ. Neither is Monroe County, the Florida Keys. Both trace to where the boundary was drawn historically.
That is the one-mile coastal band ASCE 7 defines. It runs by distance from the coastline and needs parcel-level map data we do not have.
What does this page claim, and what doesn’t it?
There are two different boundaries, and only one can be counted exactly from county data.
The HVHZ follows full county limits (all of Miami-Dade and Broward), so a county-level Census count answers the question directly. It is one of the few wind-exposure figures on this site that needs no range or upper-bound caveat.
ASCE 7 defines the WBDR by distance from the coast (generally one mile), which cuts across counties. We had no parcel-level map data to count housing inside that band, and we did not approximate one.
The HVHZ is a Florida designation. Other Gulf and Atlantic states have their own wind rules, covered in garage doors and the hurricane code. None that we found uses a full-county boundary like the HVHZ.
It is sold commercially. Every WBDR definition here comes through the UF/ESSIE report, which quotes it, as on our hurricane code and post-storm damage pages.
This page shows how much housing sits in these zones and under which code. It does not show how many garage doors there are, or how many are rated to the right standard.
Which counties are in the HVHZ, and which sit just outside?
Miami-Dade and Broward are in. Palm Beach and Monroe, right next to them, are not.
| County | Total housing units | In HVHZ? | Note |
|---|---|---|---|
| Miami-Dade County, FL | 1,085,414 | Yes | — |
| Broward County, FL | 863,128 | Yes | — |
| Palm Beach County, FL | 713,855 | No | Directly adjacent to Broward on the same coast; not part of the HVHZ. |
| Monroe County, FL (Florida Keys) | 54,418 | No | The Keys — arguably Florida’s most hurricane-exposed geography by any wind-speed measure — sit outside the HVHZ. |
Census ACS 2023 5-year estimates, table B25001 (Total Housing Units). HVHZ status checked directly against Florida Building Code Section 1620.2, which names Miami-Dade and Broward Counties with their design wind speeds.
Why can one boundary be counted and not the other?
Because one follows county lines and the other does not. We have reported other wind-exposure figures as ranges or upper bounds. Our hurricane code study sets Census year-built ranges against the debris region’s effective dates, because the WBDR is a one-mile band, not a county.
No county-level dataset can say exactly how much housing sits within one mile of a coastline.
The HVHZ is different in kind. Florida Building Code Section 1620.2 sets its higher wind speeds (up to 186 mph for the highest risk category in Miami-Dade) by naming the two counties. There is no distance-from-coast formula.
So a county-level Census count is not an estimate of the HVHZ population. It is the HVHZ population, as precise as any other county-level Census figure.
HyreGarage analysis: this tells you how far to trust each number. The 1,948,542 HVHZ figure is as certain as any county-level Census statistic. A national WBDR housing count would need a different map dataset, or modeling guesses we choose not to make and then publish as if precise.
Why are Palm Beach and Monroe Counties outside the HVHZ?
Because of code history, not lower wind risk. Palm Beach borders Broward on the same Atlantic coast and, by current wind-speed maps, faces similar hurricane exposure. Yet its 713,855 housing units are not under HVHZ rules.
Monroe County, the Florida Keys, reaches further into open water than almost any other inhabited part of the continental US. It is generally seen as one of the most hurricane-exposed places in the country. Its 54,418 housing units are also left out.
The HVHZ comes from South Florida code history that predates the modern statewide Florida Building Code. It merged the separate Dade County and Broward County codes adopted after Hurricane Andrew (1992) exposed severe building failures in South Florida.
Palm Beach and Monroe, though highly exposed to wind, were never brought under that two-county code line when the statewide code was unified.
HyreGarage analysis: in Palm Beach or Monroe, being outside the HVHZ does not mean being outside real wind exposure. The standard statewide wind rules apply instead of the stricter HVHZ ones. The two differ, as our wind mitigation credits study shows. Do not read “not HVHZ” as “no extra wind rules.”
The wind speeds make this concrete. Miami-Dade’s HVHZ requirement reaches 186 mph for the highest risk category, and Broward’s reaches 180 mph. Both are well above the 130 to 140 mph range that triggers the wind-borne debris region elsewhere in Florida.
A garage door built to the standard statewide trigger in Palm Beach is not always built to the higher bar Miami-Dade or Broward would require for the same wind. That is why the county line, not just nearness to the coast, decides which standard a product must meet.
Why does an exact HVHZ housing count matter?
Because other people price and plan against it. Insurance underwriters price wind risk differently on each side of the line. Emergency planners sizing an evacuation or a post-storm damage survey need to know how many homes sit inside the strictest building-code zone and how many sit just outside.
Local news covering a storm’s landfall often needs a sourced housing count for the area. It rarely has one that traces to a named Census table and a named code section. This one does.
How do HVHZ wind speeds compare with the statewide trigger?
They are much higher. The HVHZ counties require higher design wind speeds than the statewide threshold that defines the wind-borne debris region everywhere else in Florida.
| Area | Design wind speed requirement |
|---|---|
| Miami-Dade County (HVHZ) | Up to 186 mph (highest risk category) |
| Broward County (HVHZ) | Up to 180 mph (highest risk category) |
| Palm Beach County (standard FBC) | Set by the statewide design wind speed map, generally lower than the adjacent HVHZ counties |
| Statewide WBDR trigger (ASCE 7-22) | 130 mph or greater within one mile of the coast; 140 mph or greater anywhere |
HVHZ figures: Florida Building Code Section 1620.2. Statewide WBDR trigger, via the UF/ESSIE report: “areas within a mile of the mean high water line where an Exposure D condition exists upwind and the ultimate design wind speed is 130 mph or greater, and any area at 140 mph or greater.”
How do you check which zone applies to your address?
The county line settles the HVHZ question. For the debris region, ask your building department.
If the address is in Miami-Dade or Broward County, HVHZ rules apply. No distance-from-coast math is needed, because the boundary is the county line.
We could not verify any public map of the wind-borne debris region as authoritative. Your local building department decides whether a parcel sits inside the one-mile band, and at what design wind speed.
The number matters more than a yes or no on WBDR status. Whether it is 130 mph, 140 mph or below the trigger decides which opening-protection standard applies to a door. Our wind-rating checker walks through it.
Palm Beach and Monroe, though outside the HVHZ, still fall under the statewide wind-borne debris rules if they meet the ASCE 7 speed-and-distance trigger. Confirm the exact code section that applies.
What do the terms on this page mean?
- High-Velocity Hurricane Zone (HVHZ)
- The Florida Building Code’s strictest wind zone, defined by full county limits: Miami-Dade and Broward Counties, named directly in Section 1620.2.
- Wind-borne debris region (WBDR)
- A separate ASCE 7 zone defined by distance from the coast (generally within one mile) where design wind speeds meet a threshold. It cuts across counties, so this page does not turn it into a housing count.
- Design wind speed
- The wind speed a building in a given place must be built to withstand. ASCE 7 maps it, and the Florida Building Code and other state codes adopt it.
- Table B25001
- The Census ACS table of total housing units. We use it at county level because the HVHZ boundary matches county limits exactly, unlike the WBDR’s one-mile band.
What couldn’t we count?
An exact national or state housing count for the wind-borne debris region. That needs parcel-level map data, which county lines do not match, and we do not have it. We report the countable HVHZ figure and decline to publish a falsely precise WBDR figure.
How many garage doors in the HVHZ are properly rated. This page gives the housing count. What share of doors in Miami-Dade or Broward carry HVHZ-approved ratings is a separate question. Our product approval register study covers it from the product side.
The full legislative history of why Palm Beach and Monroe were left out. We report the widely stated explanation (the Dade/Broward code line after Hurricane Andrew). We did not trace the history document by document.
ASCE 7 itself. It is sold commercially and was not retrieved. Every WBDR definition here comes through the UF/ESSIE report, which quotes it, as in our other wind research.
Debris-region housing counts for states other than Florida. Texas, the Carolinas, Georgia and the other Gulf and Atlantic states have coastal exposure too. None uses a full-county boundary like the HVHZ that this method could count the same way.
Questions
How many housing units are in Florida’s High-Velocity Hurricane Zone?
What counties are in the High-Velocity Hurricane Zone?
Is Palm Beach County part of the HVHZ?
Are the Florida Keys in the High-Velocity Hurricane Zone?
What is the difference between the HVHZ and the wind-borne debris region?
How much housing is in the national wind-borne debris region?
What wind speed does Miami-Dade County require for the highest risk category?
Written and audited by
HyreGarage Research Desk
Primary-source research, data analysis and fact checking
We are not a garage door company. We read the agency file, the code record, the standards document or the public register ourselves, compute the figure from it, and publish it with the source and the date we retrieved it.
Where a number cannot be traced to a primary source, we publish the shorter page and say what we could not verify. Our own company records cover ten states; nothing national is ever derived from them.
- 10
- states our own company records cover — and the limit of any claim made from them
- 3,901
- garage door companies in the store
- 457
- license records verified against a state board
- 0
- national claims made from a ten-state store
How this desk works
- Primary sources only. Injury counts come from CPSC. Housing counts come from the Census file, not from a summary of it. Code history comes from the building commission that adopted the code. We do not cite an article that cites a source; we retrieve the source and do the arithmetic ourselves.
- Every figure carries its retrieval date. Registers change, datasets are revised and codes are amended. A number without the date it was read cannot be checked, so every study states one.
- Fact, calculation and analysis are labeled apart. A quote is a quote, a HyreGarage computation says so, and an interpretation says “HyreGarage analysis”. Presenting our reading of a dataset as something the agency stated would be the easiest way to lose the only thing this desk is for.
- Limitations go above the fold. If a figure is an upper bound, a bracket, or an association rather than a cause, that is said before the figure is quoted rather than in a footnote underneath it.
- No DIY instructions for spring, cable or track work. Those components hold enough stored energy to cause serious injury, and CPSC records the consequences. We describe what has failed and what a competent repair involves; we do not tell you how to do it.
Data as of Census ACS 2023 table B25001 and the Florida Building Code HVHZ provisions, retrieved 2026-09-06. Authorship on this site is organizational: the analysis belongs to the desk rather than to a named individual, and we do not publish credentials we do not hold.
Our editorial policy sets out how we source, date and correct what we publish.
Sources & retrieval dates
In Miami-Dade or Broward County?
Confirm a garage door’s HVHZ approval before you buy. Florida’s statewide product register has the exact field for it.
Find a Garage Door Professional Open the wind-rating checker
HyreGarage is not a garage door company. We do not perform, supervise or warrant garage door work. This page reports federal housing statistics and published building code provisions. It is not engineering or code advice and does not replace checking any requirement with your local building department.