What Permits Are Needed to Build an Addition?

Better to ask for permission than forgiveness when adding onto your home

Kitchen extension
Photo: James Osmond / Getty Images
Kitchen extension
Photo: James Osmond / Getty Images
Highlights
  • All permanent improvements to your land, including home additions, will require permits.

  • You may get fined or have to demolish your home addition if you fail to pull permits.

  • Permit requirements vary by location, so check with your contractor or local building department for specifics.

  • Permits for home additions cost between $500 and $2,000 and can climb higher in some areas.

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Building a home addition will add square footage and value to your property, but before you break ground, you’ll need to get permission for your project. It’s crucial to understand what permits are needed to build a home addition before you get started to avoid surprise permit fees, violations, and illegal construction. Let’s discuss what permits you’ll need and how to get them.

Can I Add a Room to My House Without a Permit?

No, you can’t legally add a room to your house without a permit. All building departments will require at least a general construction permit for a home addition, and most will require additional permits for things like plumbing, electrical, and HVAC work. Building without permission from your municipality could land you with violations and expensive fines, and you may even be forced to knock down the addition and return your property to its original condition if your building department finds out about the illegal construction.

What Permits Are Needed to Build a Home Addition?

Building a home addition is a complicated home improvement project, so depending on your plans for the construction, you'll need several different types of permits before you begin.

General Construction Permit

In almost all municipalities, you’ll at least need a general construction permit to build a home addition. This type of permit often comes with a fee equal to a certain percentage of your home addition cost. It usually covers the following work:

  • Foundation pouring

  • House framing

  • Window and door installation

  • Roofing

  • Interior and exterior finishes

You’ll need a general construction permit regardless of the type of home addition you’re planning, so it applies to everything from second-story dormers to adding a finished room on its own foundation.

Electrical Permit

You’ll need an electrical permit for any home addition involving electrical work, including wiring, electrical outlets, ceiling fans, lighting, and light switches. Some building departments will include permission for electrical work in the general construction permit, while others will require you to pull separate permits.

HVAC Permit

Similarly, an HVAC permit is required if you’re adding heating and cooling to your home addition. All fully finished living spaces and four-season sunrooms will need this permit. Your general construction permit may cover this work, as well.

Plumbing Permit

If you’re adding any type of plumbing to your home addition, you’ll need a plumbing permit unless your general construction permit covers it. This includes everything from utility sinks and wet bars to full kitchens and bathrooms. Plumbing permits also often cover work with gas lines for gas furnaces, gas stoves, and natural gas barbecues.

Foundation Permit

Many municipalities will include foundation work in the general permit, but even so, you’ll need a separate inspection for the foundation after your contractor pours it. Foundation work could also require a separate building permit, depending on where you live.

Permits for Energy Efficiency Improvements

Some states mandate specific energy efficiency home improvements, like California, which requires solar on all new construction. This will demand a separate solar permit in some areas, but in others, solar is covered under electrical permits.

How to Find Out What Permits You Need for a Home Addition

The easiest way to find out what permits are needed to build an addition is to hire a reputable home addition contractor near you. Your pro will know what permits are required and will even pull them on your behalf.

You can also do your own research by going to your local building department, discussing your project, and asking which permits you’ll need.

How to Get Permits for Your Home Addition

Your contractor will pull all of the necessary permits for your home addition, as well as schedule any final inspections necessary to close them out after the work is done. Some municipalities will allow homeowners to pull permits, in which case you can go to your building department to file for them yourself. Most will only issue them to licensed contractors, though.

Price Notice

Permits can actually be quite expensive. Talk to your contractors before starting your project to understand how much the required permits will cost you.

Frequently Asked Questions

While it’s physically possible to build an addition on your house yourself, most municipalities won’t issue the necessary permits for home additions to unlicensed individuals. If you have the experience necessary for the project, you could have a contractor who builds home additions pull the permits for you, then do the work yourself and have your GC sign off on the work to close out the permit. It’s best to leave large-scale projects like this to the pros, though, and just consider DIYing the finishing work, like hanging drywall, painting, and installing flooring.

Yes, a sunroom will require a permit. You may just need a general construction permit for a screened-in porch or solarium. For a three-season room with electricity and a four-season room with electric, heating, and cooling, you’ll need additional permits for each of the utilities, as well as a roofing permit.

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