Costly rentals or equipment—you might want to leave this one to a pro.
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What you'll need:
TOOLS
Circular saw
Jigsaw
Post hole digger/auger
Power drill
Stud finder
Climber
SUPPLIES
3-inch screws
Lag screws
Cement
Rebar
4-by-4s or 6-by-6s
6-inch-wide boards
12-inch deck lumber
Caulk or flashing
Corner brackets
Premade balcony railing
Imagine how relaxing it would be to sip a warm cup of coffee—or a frosty beer—from the comfort of your own two-story balcony. Guess what? It's totally possible if you're willing to put in the work. However, building a balcony from scratch isn't a project for the casual weekend DIY warrior. But with some thorough planning and careful work, you can realize the dream of building a balcony onto your home. Learn how to build a balcony in this step-by-step guide.
Prepping to Build a Balcony
Treat this guide as a rough outline for your project. Each homeowner will need to check local codes and ordinances and consider their current yard when designing their build. Depending on your municipal building authority, you might need a permit, which costs around $25 in many states. Failure to do so could result in the whole deck being removed, as well as substantial fines.
In addition, make sure you figure out how much wood you'll need. Your joists and frame pieces will vary based on the dimensions you choose. It will also factor in when deciding how big your post holes will be. A small balcony is usually 4 feet by 9 feet, which creates enough room for a small table and two people to sit. Slightly bigger would be 5 feet by 10 feet or 5 feet by 12 feet, which can fit a table and things like a balcony garden.
Install Post Holes and Insert Cement
Use an auger or post hole digger to create four post holes. Again, check local ordinances to determine how deep the holes need to be for a balcony or second-story deck. Each post hole should be three times the diameter of the piece of lumber.
Place your 4-by-4 or 6-by-6 posts into the hole, then fill with cement to secure them. You'll likely need an extra set of hands for holding the beams still as one person pours cement and sets it. Read your quick-drying cement instructions and follow them carefully.
If you're building an especially heavy or large deck, insert rebar into the top of each post hole.
Drill a Ledger Board Into the Rim Joist of Your Home
The first step for building the balcony frame is to secure a ledger board to your rim joist. You'll need to remove siding from the home to get direct access. Use lag screws to drill the board into your foundation—approximately every 12 inches.
The ledger should be as close to the home as possible. Assuming an entryway is above it, the board should be as fit and snug as possible underneath to prevent water seepage from rotting the wood over time. Install flashing or caulk when you're finished to prevent leaks.
Build Your Balcony Frame
To build the frame, attach the 2-by-6s to the ledger board. The outside portion of your balcony should be double-framed for support. Use two boards cut to the same length on all three sides not touching the rim joist. Screw them in with two lag screws fitted to a corner bracket.
If possible, position your double frame directly underneath a double stud in the wall. Use a stud finder to locate stud points and mark them with a pencil or pen.
Lastly, attach your frames to the posts using lag screws and a corner bracket.
Secure Your Joists
Install the balcony joists or wood beams that'll form the base of the floor. Insert a 6-inch board every 12 inches, starting at the rim joist, then securing it to the opposite side of the frame.
You can buy deck boards at home improvement stores for around $20 per piece. It's up to you whether you'd like to cut these into individual 12-inch pieces and layer or install them as one long beam across your hoists.
Deck boards are usually 5 1/2 inches wide and 1 inch thick. You'll establish the board length needed after determining the size of the balcony. Use screws to fasten boards to your joists. Work slowly and use nails to reinforce if needed.
Install Hand Railings
For railings, you can either use lumber or buy a premade balcony railing kit from a home improvement store. The latter will cost between $60 and $100 for 6 feet of railing.
Read the manufacturer’s directions on your kit. In either case, you'll likely need to drill holes every 3 to 6 inches—depending on railing gaps—into your doubled-up balcony frames. Drill starter holes, then fasten using screws or as described on the packaging.
Building a Balcony DIY vs. Hiring a Pro
Since this is a substantial DIY project, hire a balcony contractor near you with experience to guarantee that the job winds up looking exactly the way you want it to. Building a balcony is a challenging proposition involving lots of cutting, drilling, and setting. You will have to work from a ladder and drill directly into your home's rim joist—which, if damaged, could compromise the structural integrity of your home.
Balcony construction or replacement typically requires a building permit from your local permitting authority. Safety and building integrity are the main reasons for the need to obtain a permit and the subsequent inspections. In some cases, especially cantilevered balconies, your municipality may also require the oversight and signature of a structural engineer.
There are several methods of supporting a balcony. Very small balconies, such as Juliet balconies that don't include any usable floor space and don't need to support human weight, may simply require supporting bolts drilled into the home's structure. Cantilevering is a method that requires no additional exterior supports, and larger balconies typically need posts and footings to carry the weight from below.
Depending on how you design your balcony is the most essential factor when talking about how much your home's balcony can hold. The typical weight a balcony can support ranges between 50 and 100 pounds per square foot. However, it's possible to exceed those limitations with careful planning by a structural engineer.
Deane has spent 30+ years in residential construction, contracting, remodeling, maintenance, and home repair, and now contributes DIY and educational articles for publications like Forbes Home and U.S. News. Throughout his career, he has strived to help homeowners find the potential hidden within the walls of every home and empower them to take control of their household repair and remodeling endeavors.
Deane has spent 30+ years in residential construction, contracting, remodeling, maintenance, and home repair, and now contributes DIY and educational articles for publications like Forbes Home and U.S. News. Throughout his career, he has strived to help homeowners find the potential hidden within the walls of every home and empower them to take control of their household repair and remodeling endeavors.
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