You've sketched out a beautiful deck, picked the materials, and you're ready to start building. But before you break ground in Cary, IL, there's a step that trips up more homeowners than almost anything else: the building permit. Many people assume that because they own the property, they can build whatever they want. That assumption can cost you thousands in fines, forced tear downs, and headaches that linger for years. In Cary, the deck permit process is straightforward once you know what you're dealing with. Here's exactly what you need to know in 2026.
When Do You Need a Permit for a New Deck in Cary, IL?
The short answer is almost always. Cary's building code, like most municipalities in McHenry County, requires a permit for any deck that is attached to the house or exceeds 200 square feet. If your deck is freestanding and under 200 square feet, you might be able to skip the permit, but that's a narrow exception. The village defines a deck as any platform more than 12 inches above grade, so even a low platform raised just a foot off the ground needs a permit.
The key reason is safety. A deck that's improperly attached to your home can pull away from the house under the weight of people, snow, or ice. Cary's winters are no joke, and a deck that isn't built to code can become a serious hazard. The permit process forces you to meet minimum standards for footing depth, structural connections, and railing height that are specific to your property's soil conditions and frost line (which in Cary is typically 42 inches deep).
If you're hiring a contractor like Burns Carpentry, they handle the permit as part of their standard process. In fact, our team at Burns Carpentry manages the entire application with the Cary municipal offices, so you don't have to worry about missing a step. But if you're doing it yourself, you need to know exactly what the village requires.
Step-by-Step Guide to Applying for a Deck Building Permit in Cary
The application process in Cary is handled through the Community Development Department at 255 Briargate Road. Here's the sequence that works, based on what we've seen dozens of homeowners go through in the last few years.
First, get your property survey ready. You'll need a plat of survey that shows your property lines, the location of your house, and any existing structures. This is the single most common piece of paperwork that gets rejected. If you don't have a recent survey, you can get one from a local land surveyor for $300 to $500. The village needs to verify your deck won't encroach on the required setbacks (more on those in a moment).
Second, draw up your plans. You need a scaled drawing that shows the deck's dimensions, the location of footings, the size of the beams and joists, and the railing system. It doesn't have to be fancy, but it has to be accurate. Include the distance from the deck to each property line. If you're using a professional like Burns Carpentry, we provide these drawings as part of our design phase. If you're going solo, you can use graph paper and a ruler, but be precise.
Third, submit your application. You'll fill out a building permit application form (available on the village website or at the office). The fee for a typical residential deck in Cary ranges from $150 to $350 depending on the square footage and complexity. You pay this at submission. Expect to wait while the plan examiner reviews your drawings for code compliance.
Fourth, schedule inspections. Once the permit is issued, you'll need at least three inspections: footing inspection (before you pour concrete), framing inspection (before you install the decking), and final inspection (after everything is complete). Each inspection costs about $50 and requires a call to the building department to schedule. Miss an inspection and you could be forced to tear out work to show what's underneath.
If this sounds like a lot of moving parts, it is. That's why most homeowners in Cary choose to work with a contractor who handles the whole thing. Burns Carpentry's Essential Deck Package includes permit management, so you don't have to track down forms or schedule inspections yourself.
Common Deck Permit Requirements: Setbacks, Footings, and Railings
Three areas trip up more DIY deck builders than anything else: setbacks, footings, and railings. Get these right and the rest of the process is smooth.
Setbacks. Cary requires your deck to be at least 5 feet from the side property lines and 20 feet from the rear property line. If your lot has an easement, that distance might be larger. The village also requires a minimum of 3 feet from the deck to any other structure on your property, like a shed or garage. These distances are measured from the edge of the deck, not the house. If you're building a wrap around deck, those measurements get complicated fast.
Footings. Cary follows the International Residential Code (IRC) for footing depth. Because the frost line in this part of Illinois is 42 inches, your footings must extend at least 42 inches below grade to prevent frost heave. The footing diameter depends on the load, but a typical 10x10 deck needs footings that are at least 12 inches in diameter. The village also requires that footings be placed on undisturbed soil, not fill dirt. If you hit clay or rock, you may need a soils engineer to sign off.
Railings. Any deck surface that is 30 inches or more above the ground must have a railing. The railing height must be at least 36 inches. The balusters (the vertical pieces) cannot be spaced more than 4 inches apart. This is a safety standard designed to prevent small children from slipping through. If you're using glass or cable railings, you'll need to show the plan examiner that the system meets the same spacing requirements.
One detail that surprises many homeowners: the stairs also need a permit. Every step must have a rise between 4 and 7.75 inches, and the tread depth must be at least 10 inches. Handrails are required on any staircase with four or more risers.
How Long Does the Permit Process Take in Cary?
In our experience, a deck permit in Cary takes about two to four weeks from application to approval. The village's plan examiner has 10 business days to review your application. If everything is in order, you'll get your permit shortly after that. But if your drawings are incomplete or the setbacks are off, you'll get a correction notice that can add another week or two to the timeline.
The best time to apply is early spring, typically March or April. That's when the village is less busy than the summer rush. If you apply in June or July, you might be waiting three to four weeks because everyone else is building too. We've seen homeowners who applied in mid May get their permit in 12 days, while those who applied in late June waited 28 days.
Once you have the permit, you have 180 days to start construction and 365 days to finish. If you exceed either deadline, you'll need to request an extension (which costs another fee, typically $50).
For Burns Carpentry clients, our typical deck building project in Cary takes three to five weeks from initial consultation to completion. That includes the permit waiting period. We start the permit application as soon as you sign off on the design, so the clock starts ticking immediately.
What Happens If You Build Without a Permit? Risks and Penalties
Building without a permit in Cary is a gamble that rarely pays off. The village building inspector patrols neighborhoods, and neighbors do report suspicious construction. If you're caught, the penalties are immediate and serious.
First, you'll be hit with a stop work order. That means you can't touch the deck until you get a permit. If you've already poured footings or built framing, you'll need to expose those elements for inspection, which might mean digging up concrete or removing deck boards. That costs you time and money.
Second, the village will charge a penalty fee equal to double the original permit fee. So if your permit would have cost $300, you'll pay $600. And you still have to pay the original fee on top of that.
Third, if your deck doesn't meet code, you'll be forced to tear it down and rebuild. We've seen homeowners in Cary lose $5,000 to $15,000 in materials and labor because they tried to skip the permit and ended up with a deck that was unsafe. The village doesn't grandfather in existing construction. If it's not to code, it has to come down.
Fourth, when you sell your home, the buyer's home inspector will check for permits. If they find an unpermitted deck, you'll either have to get it retroactively permitted (which means opening up the structure for inspection) or offer a credit to the buyer. Either way, it's a negotiation point that hurts your sale price.
The bottom line: the permit fee is a small price compared to the cost of fixing a mistake. If you're not sure whether your project needs a permit, call the Cary Community Development Department at 847-639-0003. They're helpful and will tell you exactly what you need.
Frequently Asked Questions
How much does a deck permit cost in Cary, IL?
For a typical residential deck, the permit fee in Cary ranges from $150 to $350 depending on the size and complexity. This includes the plan review and the first inspection. Additional inspections cost about $50 each.
Do I need a permit for a freestanding deck in Cary?
Yes, if the deck is more than 12 inches above grade or exceeds 200 square feet. A low platform under 200 square feet that sits directly on the ground might not need a permit, but it's always safer to check with the village first.
Does Burns Carpentry handle the permit process?
Yes, Burns Carpentry manages all required permits for deck building projects in Cary. We handle the application, drawing submittals, and inspection scheduling so you don't have to. It's part of our standard service.
How long is a building permit valid in Cary?
A deck permit in Cary is valid for 180 days from the date of issuance. Construction must be completed within 365 days. If you need more time, you can request an extension for a small fee.
Building a deck is one of the best investments you can make in your Cary home. But getting the permit right is the difference between a weekend project and a legal nightmare. If you want a deck that's built to code, designed to last through Illinois winters, and managed from start to finish by professionals who know Cary's requirements inside and out, give Burns Carpentry a call. We'll handle the permit, the design, and the construction. You just get to enjoy the finished space.
