How to Find Your Exact Wind & Snow Load Zone Before You Order (ASCE Hazard Tool Walkthrough)

You've picked your size. You've picked your roof style. Then the order form asks for your wind speed rating and ground snow load, and you're stuck typing "not sure" into a box that needs a real number. Guessing here isn't a small risk.

Order the wrong rating and your building fails inspection, or worse, it fails in the first real storm. The good news: the exact number for your address is public, free, and takes about five minutes to pull. This walkthrough shows you exactly how, using the same tool engineers use.

Key highlights

• The ASCE Hazard Tool is free. No account, no login, no catch.

• Your wind speed and ground snow load come from your exact street address, not your zip code or your state average.

• You'll be asked to pick a Risk Category before the tool gives you a number. Get this wrong and every number after it is wrong too.

• Most carports, hay barns, and unoccupied storage buildings fall under Risk Category I. Garages, workshops, and anything with regular foot traffic usually land in Risk Category II.

• The tool generates a free PDF report you can hand to your local permit office or send to us when you request a quote.

• Your local building department or authority having jurisdiction decides which ASCE 7 edition applies (7-16 or 7-22), not the tool. Confirm that first, before you pull your numbers.

• Once you have your numbers, call (888) 579-0934. We'll match your building spec to your actual location instead of a guess.

Why guessing your wind and snow numbers costs you later

A metal building isn't one-size-fits-all. Wind speed and snow load change your framing gauge, your anchor pattern, and sometimes your roof style entirely. Order based on a guess and one of two things happens. Either you pay for more steel than your site actually needs, or you end up with a building that can't pass inspection, or that takes real damage in the first bad storm.

Permit offices catch this fast. Most local building departments want a specific wind speed in miles per hour and a specific ground snow load in pounds per square foot written on your application. "About 120, I think" doesn't work on a stamped drawing, and it definitely doesn't work if an inspector asks where that number came from.

So here's the fix: pull your real numbers before you order, not after.

What the ASCE Hazard Tool actually gives you

The official ASCE Hazard Tool instructions explain how the tool pulls data from the ASCE 7 standard, the same standard referenced inside most U.S. building codes. It covers eight hazard types in total: wind, snow, seismic, ice, rain, flood, tornado, and tsunami. For a metal carport, garage, or barn, you really only need two of those: wind and snow.

Wind speed and exposure

The tool reports a 3-second gust wind speed, measured 33 feet above the ground, using Exposure Category C as the baseline. That's the standard reference point engineers use: open terrain with scattered obstructions under 30 feet tall. If your actual site sits behind a treeline, up on a ridge, or right on the coast, your real-world exposure could run higher or lower than the baseline number. Worth mentioning to whoever ends up stamping your drawings, and worth reading through our guide to wind ratings and metal building design if you want the fuller picture on exposure categories.

Ground snow load

Ground snow load comes back in pounds per square foot. That's not the same thing as your roof's snow load. Roof snow load gets calculated afterward, using ground snow load plus factors for roof slope, exposure, and how the building gets used. Nobody expects you to run that math by hand. Your building's engineer does that part, and we walk through the difference in more detail in our post on wind and snow load ratings for metal buildings.

Step-by-step: pulling your numbers from the ASCE Hazard Tool

Step 1: go to ascehazardtool.org and enter your address

Type your full street address into the search bar. Not just your city, not just your zip code. Wind speed and snow load can shift meaningfully within the same zip code, especially in mountain counties or anywhere near a coastline. You can also enter latitude and longitude, or drop a pin directly on the map if that's easier.

Step 2: confirm which ASCE 7 edition your local building department uses

Before you get results, the tool asks which standard edition you want: ASCE 7-10, 7-16, or 7-22. This matters more than people expect. Older local codes may still reference 7-16, while newer adopted codes reference 7-22, and the numbers aren't always identical between editions. Call your local building or permitting office and ask directly which edition they require on permit applications. Don't guess this one.

Step 3: select your Risk Category

This is the step people skip past too fast. Your Risk Category (I, II, III, or IV) directly changes the wind and snow numbers the tool hands back. We break down exactly which category applies to which building type in the next section, and in more depth in our full Risk Category guide.

Step 4: choose wind and snow as your load types

The tool covers all eight hazard types by default. For a carport, garage, or barn, uncheck everything except wind and snow, unless your area also carries a real seismic or flood concern worth noting. Keeping your report focused makes it easier to read and easier to hand off later.

Step 5: pull your report

You've got three ways to view your results. Click Details for an on-screen popup with your numbers. Click Full Report for a downloadable PDF with everything documented. Click Summary for a plain-text version you can copy straight into an email. Save the PDF. That's the version your permit office and our team will both want to see.

Which Risk Category actually applies to your building?

Risk Category comes from the International Building Code Risk Category requirements, and it's based on how your structure gets used, not how big it is or what it's made of. Get this one right and everything downstream, your wind rating, your snow rating, your framing spec, lines up correctly.

If you're not sure which category fits your project, your local permit office makes the final call, not us and not the tool. Most of our customers land in Category I or II. Call (888) 579-0934 and we'll help you figure out which one matches your plans before you design your building in our 3D estimator.

Have your Risk Category and load numbers? Match them to the structure you need by comparing certified metal carports, certified metal garages, or certified metal barns. For help choosing the right category, call (888) 579-0934.

What to do with your numbers once you have them

Once you've got your wind speed and ground snow load, they're useful in two places. First, bring the PDF to your local building or permit office and confirm it lines up with what they expect on an application. Second, bring it to us when you request a quote. We'll build your spec around your actual numbers instead of a generic minimum.

One thing worth saying plainly: pulling your numbers from the ASCE Hazard Tool is not the same as having a stamped engineering drawing. It's the starting point that makes stamped engineering accurate, not a replacement for it. If your jurisdiction requires a certified building with stamped drawings, our certified versus non-certified guide walks through what that adds and when you actually need it. And before you get anywhere near a permit office, it's worth a quick read through our metal building permit checklist so you know what else they'll ask for.

Keep your ASCE PDF with your project notes. When you're ready to price the building, send the report with your quote request or call (888) 579-0934 so the team can review the location, use, and certification needs with you.

Common mistakes people make with the tool

• Entering a zip code instead of a full street address is the most common one. Numbers can shift inside the same zip, particularly in counties with real elevation change or coastal exposure.

• Defaulting to Risk Category II without checking whether your structure actually qualifies as Category I is another. An open hay barn with no regular occupants is a different animal than an enclosed workshop, and picking the wrong one can push you into paying for more steel than your project needs.

• Assuming a builder's marketing page (170 MPH! Rated for anything!) reflects your exact address is a third. Those numbers are usually a maximum capability or a minimum baseline, not a location-specific rating pulled for your property.

• Forgetting to confirm the ASCE edition with your local building department before pulling numbers is a fourth. Pull the wrong edition and you may need to redo the whole report.

• And treating the Exposure Category C output as the final word, without mentioning real trees, hills, or coastline near your site, rounds out the list. That context belongs in the conversation with whoever engineers your building.

Why order with real numbers instead of a guess

We build to your actual wind speed and snow load, not a generic minimum pulled out of thin air. If your jurisdiction requires a certified building, we can provide stamped engineering drawings that match the numbers you pulled.

Delivery and installation are included on our buildings, and financing and rent-to-own options are available if you'd rather not pay everything up front. Design your building at GetCarports.com, or call (888) 579-0934 and we'll walk through your numbers with you directly.

Frequently asked questions

Is the ASCE Hazard Tool free to use?

Yes. It's maintained by the American Society of Civil Engineers, and there's no login, no account, and no cost to look up your wind speed and ground snow load. You can generate and download a full PDF report at no charge.

What Risk Category should I pick for a metal carport or barn?

Most open carports, hay barns, and unoccupied storage buildings fall under Risk Category I. Garages, workshops, and buildings with regular foot traffic usually fall under Category II. Your local permit office has the final say if you're unsure.

Do I need my exact street address, or will my zip code work?

Use your exact street address. Wind speed and ground snow load can shift within the same zip code, especially in mountain or coastal counties, so a zip-level number isn't precise enough for a permit application.

Which ASCE 7 edition should I select, 7-16 or 7-22?

That depends on which edition your local jurisdiction has adopted into its building code, not on which one is newest. Call your local permit office and ask directly before you pull your report.

Does the wind speed on a builder's website match what the tool gives me for my address?

Not always. Marketing numbers are often a general minimum or maximum capability across an entire product line. Your address-specific number from the ASCE Hazard Tool is the one your permit office and your building's engineering should actually be based on.

What do I do with my report after I download it?

Bring it to your local building or permit office to confirm it matches what they expect on an application, and bring it to us when you request a quote. We'll build your spec around your real numbers.

Conclusion

Your exact wind speed and ground snow load aren't a guess you make at checkout. They're a five-minute lookup at a free tool, tied to your actual address and your actual Risk Category.

Pull your numbers before you order, confirm your ASCE edition with your local permit office, and bring both to whoever's building your structure. Design your building at GetCarports.com, or call (888) 579-0934 and we'll help you turn those numbers into the right spec.

Ready to match the numbers to a building? Browse metal buildings for sale or call (888) 579-0934 to talk through your wind, snow, and certification requirements.