Do You Need a Permit? A Janesville Homeowner’s Guide to Building Permits

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Ask any homeowner who’s built anything outdoors, and you’ll hear the same thing: “I didn’t want to deal with permits.” Then they end up dealing with permits anyway — usually at the worst possible moment, when a buyer, an insurance adjuster, or a city inspector shows up and points at unfinished work.

Here’s the honest truth: permits are not an obstacle to your project. They’re a protection of your project. A permitted, inspected job sells faster, insures better, and avoids the expensive problems that come with unpermitted work. It also protects your property value in ways most people never consider until it’s too late.

Because permit rules vary from municipality to municipality, this guide covers the general framework that applies across Janesville and Rock County, plus the specific questions homeowners ask us most. Always confirm current requirements with the City of Janesville or Rock County building department before you start — rules change, and we’re happy to help you figure out what your specific project needs.

Why Permits Matter More Than Most Homeowners Think

Most people treat a permit as a tax on their project. It’s better understood as insurance.

Resale Value

This is the big one. Unpermitted work creates a “cloud” on a property that buyers and their inspectors can detect. An unfinished room with no permit, a basement bedroom with no egress window, a deck that was never inspected — these create doubt. In a buyer’s mind, unpermitted work means something might be unsafe, might be illegal, or might need to be torn out and redone. That uncertainty gets priced in as a discount.

Insurance Claims

If you build something without a permit and it later fails — a deck collapses, a retaining wall gives way, a fence falls onto a car — your insurance company may deny the claim. Permit and inspection records are the paper trail that proves the work was done to code by a licensed professional. Without them, you’re arguing against a policy exclusion.

Safety

Permits aren’t bureaucratic busywork. They exist because code requirements — footing depth, beam spans, ladder ratios, railings, guard heights — were written after failures happened to real families. A permit means someone who knows those requirements is checking the work.

Liability

If an inspection confirms the work meets code, that’s strong evidence against any future claim that it was negligent. Permits shift the burden of proof away from you.

Bottom line: A permit is a piece of paper that says “this was done right.” That’s worth a lot at resale and priceless after a claim.

Fence Permits: When You Need One

Fences are the most common source of confusion, and for good reason — the rules are genuinely different for each municipality, and even within Janesville the answer can depend on specifics.

Typically NOT Requiring a Permit

• Vinyl and wood picket fences
• Decorative fences under a certain height (often 4 feet)
• Repairs or replacement of an existing fence in the same location
• Fences on residential property between single-family homes

Often DOES Require a Permit

• Vinyl privacy fences and tall solid fences — many jurisdictions require a permit at 4 feet or 6 feet, and these are commonly reviewed for structural code and setbacks
• Chain link and aluminum fences — surprisingly, these are often subject to the same height thresholds even though they’re visually open
• Fences on corner lots — sight-line requirements at intersections
• Fences that change the use of a space — for example, enclosing a deck for a sunroom or aboveground pool
• Anything on a property with an HOA — many HOAs have additional, stricter rules

The Two Things That Matter Most

Regardless of whether a permit is required, two things determine whether your fence will still be standing in five years:

1. Post depth. In Rock County, posts need to go below the frost line — typically 42–48 inches, depending on your specific location and soil. We set them in concrete and leave the top of the post exposed above grade. Set them too shallow and the freeze-thaw cycle will heave the entire fence out of alignment within a few winters. This is the single most common fence failure we repair.

2. Line of fence and location. Fences generally need to be within a certain distance of the property line, and corner-lot visibility triangles must stay clear. Getting this wrong means a fence that has to come down and be rebuilt.

Deck Permits: Almost Always Required

If you take one thing from this guide, make it this: building a deck almost always requires a permit.

Any deck over a certain height — commonly 30 inches above grade — that is attached to or elevated above your home requires a permit and plan review in essentially every Wisconsin municipality. Most are above that threshold. Even a “simple” 12×12 deck at 30 inches will pull a permit.

What a Deck Permit Covers

• Footings – size, depth, and frost placement
• Ledger board attachment – how the deck connects to your house
• Beam and joist spans – sizing based on load calculations
• Joist spacing – typically 16 inches on center
• Railing and guard requirements – if the deck is elevated more than 30 inches
• Stair dimensions – rise, run, and width standards
• Footing inspection – the inspector comes out before the deck is covered, so the framing is visible

Why Footing Inspections Matter

A deck’s entire weight transfers through its footings into the ground. If footings aren’t deep enough, aren’t below frost line, or aren’t wide enough for the soil, the deck heaves, the ledger pulls away from the house, and the structure fails. This is why inspections happen mid-project — the frame has to be visible.

Two Critical Wisconsin-Specific Notes

Ledger attachment. If your deck attaches to your house, the ledger must be flashed and fastened into your rim joist with approved structural screws or bolts — not lag screws into drywall, and not simply screwed into siding. This is where we see the most DIY failures, and it’s the #1 thing inspectors flag.

Attached vs. freestanding. A deck attached within 15 feet of the house may need to meet guard requirements even if it’s low. A freestanding “patio deck” with a railing can sometimes qualify for a different permit path. These distinctions are worth getting right before you build.

Shed and Accessory Structure Permits

The answer here depends almost entirely on size.

Generally No Permit

• Sheds under 100 square feet with a foundation footprint under 120 square feet, that are not used for sleeping
• Small garden sheds and toolboxes
• Many municipalities exempt these entirely

Generally Requires a Permit

• Anything over 100–120 square feet
• Any shed used as a living space, office, or sleeping area
• Sheds with electrical service
• Sheds with a foundation other than a simple gravel pad
• Sheds that require a zoning variance or sit in an easement

The Big Catch: “Accessory Structure” Rules

The moment a shed becomes a bedroom, a home office with a desk, or a gathering space with heat, it can trigger building code requirements that a simple shed doesn’t need — insulation, egress windows, smoke and CO detectors, minimum ceiling height, electrical permits.

This is the most common problem we find with sheds in Janesville neighborhoods. Someone built a beautiful 12×16 shed in 2019, used it as an office for two years, and now can’t sell the house without bringing it into compliance.

If you plan to use a structure as anything other than storage, get the permit up front.Retrofitting an egress window into a finished shed wall is far more expensive and disruptive than planning for it from the start.

Concrete Work: When a Permit Applies

This one surprises people, because concrete is usually thought of as “just a flat slab.” Here’s where it crosses the line.

Typically No Permit

• Standard flat patios, sidewalks, and driveways at grade level with no attached structures
• Decorative stamped or stained concrete over an existing slab
• Repair and rescaling of existing flatwork
• Small pads for HVAC units or generators

Often Requires a Permit

• Concrete patios with attached walls, seat walls, or fire pits — these become structures
• Steps or stairs above a certain height
• Any slab attached to a structure
• Retaining walls above a certain height — commonly around 4 feet, or lower if the wall supports a driveway or structure
• Foundations, footings, and slabs for buildings
• Poured walls with openings

Retaining Wall Notes for Rock County

Many municipalities require permits and engineered drawings for retaining walls above 4 feet, and lower thresholds apply to walls supporting a driveway (called “surcharge” loads). Walls built for slope stabilization on a residential lot generally do not require engineering.

Don’t guess on this one. A wall over the threshold built without a permit can be ordered to be torn down. We can tell you quickly from a photo whether your wall is likely to require a permit and engineered plans — and if it does, we’ll help you get the right professional involved.

Egress Window Permits: Never Optional

Of everything on this list, egress window installation has the least flexibility. If you are finishing a basement bedroom, a permit is required. Period.

Why It’s Non-Negotiable

An egress window is a life-safety system. It needs to meet minimum net clear opening requirements (commonly 5.7 square feet), minimum opening dimensions, and a maximum sill height so a person can actually reach it. Below-grade installations also need a window well sized for escape, a permanent ladder or steps if the well is deep, and proper drainage.

What Gets Inspected

• Rough inspection – after the foundation is cut and the opening is framed, before the window goes in
• Final inspection – after the window, well, ladder, and drainage are complete

The Drainage Piece People Forget

This is where most of our egress calls come from. A window well without proper drainage willeventually hold water and leak into the finished basement. We engineer the well drain to daylight or connect it to a sump system, and we grade the surrounding soil so water moves away from the foundation. In our climate — heavy spring runoff plus snowmelt — this is not optional detail work.

Don’t Skip the Permit to “Save Time”

Every month we meet homeowners who already have a finished basement bedroom with no permit and no egress window. When they list the house, they find out at the last minute that the room isn’t a legal bedroom. Now they’re facing an inspection, a possible removal of drywall, and weeks of delay at the worst possible time on the real estate timeline.

Getting the permit first is always faster.

A Quick Reference: When to Call the Building Department

Project	Permit Likely?	Notes
Privacy fence (vinyl, tall)	Often	Height thresholds vary
Picket or decorative fence (low)	Usually not	Check local height rules
Deck, elevated, any size	Almost always	Plan review + footing inspection
Shed under 100 sq ft	Usually not	Confirm with city
Shed over 100–120 sq ft	Usually yes	Plus zoning review
Shed used as living space	Always	Full building code applies
Flat patio, sidewalk, driveway	Usually not	No attached walls
Patio with seat wall or fire pit	Often	May be structural
Retaining wall under ~4 ft	Usually not	Unless surcharge load
Retaining wall over ~4 ft	Often	May need engineered plans
Egress window install	Always	Rough + final inspection
Concrete repair / resurfacing	Usually not	Maintenance work

Always confirm with the City of Janesville or Rock County building department — requirements vary and change.

How Bello Handles the Permit Process

Here’s where we save you the most stress. Permit paperwork is one of the most tedious parts of any project, and it’s the part most likely to delay your timeline. We handle it.

• We identify what’s required before the first shovel hits the ground
• We prepare and submit your application — site plans, elevations, footing details, construction drawings
• We schedule all inspections and make sure they happen on schedule
• We build to code as the standard, not as an afterthought
• We handle any corrections that come back from the plan reviewer or inspector

For egress window work specifically, we do the whole job from permit to finished, well-drained installation. For decks and fences, we coordinate the permit and inspections so you never have to chase a city inspector yourself.

The One Thing to Take Away

If you’re on the fence about whether you need a permit, here’s the decision rule:

If you’re wondering, you probably need one. The projects that turn out to not need a permit are simple, small, and obvious. The ones that leave you guessing are the ones with code requirements attached.

And if you’re not sure, call us. A five-minute phone call to (608) 607-2252 can save you weeks of delay, thousands of dollars in rework, and a serious headache when you go to sell.

Get a Free Project Consultation

Bello Property Services has been building outdoor spaces across Janesville and Rock County for over a decade. We’ll walk your property, talk through what you’re planning, tell you exactly what permits apply — and what don’t — and give you a clear, honest quote. No pressure, no surprises.

Call (608) 607-2252

Bello Property Services
Janesville, Wisconsin 53546
(608) 607-2252
eloybello1994@gmail.com