DIY Floating Window Box
Instantly elevate your curb appeal and add life to your home with a "floating" window box.

Kamron and Ellie Sanders
Tools and Materials
- (1) 1x8 x 12' pine board
- (1) 1x3 x 8' pine board
- (2) 1x2 x 8' pine boards
- (1) 2x6 x 8' pine board
- tape measure
- ruler + speed square
- pencil
- miter saw
- wood glue
- wood filler
- staple gun + staples
- putty knife
- orbital sander + sandpaper
- Danish oil
- cloth
- nitrile gloves
- drill + 1/4" drill bit
- 3" wood screw + matching bit
- potting soil
- assorted plants
Step 1: Cut Frame

Kamron and Ellie Sanders
Start by measuring your window and adding two inches for a box that is slightly wider than the window. The front, back, bottom and sides of the window will all be cut from the 1x8.
Use this formula when making your cuts:
Front: the width of your window plus two inches
Back: 1-1/2 inches shorter than the front
Bottom: 1-1/2 inches shorter than the front
Sides: 9-1/2 inches each
Our window was 32 inches wide, so we made the front of our box 34 inches wide. The back and bottom measured 32-1/2 inches wide. And the sides were both 9-1/2 inches wide.
Step 2: Mock-up Window Box

Kamron and Ellie Sanders
Assemble the window box. Before securing, ensure that all cuts have been made accurately and that once fastened, there will be no gaps or mismatched pieces. This will be of great value once you begin to attach the trim and align the miters. The two side pieces will sit behind the front piece rather than beside with the back and bottom pieces sitting within the sides and behind the front. This allows for the edge grain to be covered in the front and maximizes the internal dimension while maintaining the desired external dimensions.
Step 3: Glue and Staple Box

Kamron and Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders
Once you've ensured the cuts are accurate and the window box has taken its shape, securely fasten the 1x8 boards using wood glue and staples. Glue all joining surfaces to ensure a connection that will hold up over time and support the weight of your window box's future contents. Staple the box together thoroughly. If you don't own a staple gun, a hammer and brad nails will do the trick. Once stapled, wipe the excess glue to minimize the amount of sanding you will have to do later.
Step 4: Attach Trim to Top

Kamron and Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders
At this point, the window box should be very sturdy, though just a wee bit drab. Add some flare by attaching trim. The trim is not essential to the rigidity and strength of the box, so you can do as little or as much as you desire. To add trim to the top edge, cut the 1x3 into four pieces with 45-degree cuts on each end. The short point will be determined by the internal dimensions of the box. So, for our box, the side pieces had a 7-1/4” measurement, while the front and back trim had a 32-1/2” measurement. Attach with staples.
Step 5: Attach Trim to Front and Sides

Kamron and Ellie Sanders

Kamron and Ellie Sanders
For the vertical trim on the front and sides, measure and cut four 1x2 x 7-1/4" pieces. For each piece, create a 45-degree cut on one end only. The other ends will remain straight.
For the bottom edge trim on the front of the box, cut one 1x2 x 35-1/2” piece, and create a 45-degree angle on both sides. For the two pieces of trim on the bottom sides, cut two 1x2 x 9-1/2" pieces. Attach with staples.
Step 6: Drill Drain Holes

Kamron and Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders
Using a ruler and speed square, make a grid to determine how many drains holes should be drilled. This will be based on the size of the finished box as well as the plans for what will be planted in the box. Once a grid has been drawn and marks made where the holes will be, drill 1/4" holes into the base of the window box.
Step 7: Sand and Finish

Kamron and Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders
Fill the holes left by your staples and any other unwanted gaps with wood filler. Once dry, use an orbital sander to knock down any high spots or other rough spots.
Step 8: Apply Stain

Kamron and Ellie Sanders
Rub Danish oil into every crevice of the window box. Danish oil provides a beautiful finish while also helping to protect the wood from weathering. Choose an oil or stain that best suits your taste and needs.
Step 9: Hang Window Box

Kamron & Ellie Sanders

Kamron and Ellie Sanders

Kamron and Ellie Sanders
To achieve the "floating window box" look, it is essential that no brackets or other means of mounting are visible. With 3" screws, fasten a 2x6 (cut the same length as the back piece of your window box) below the window where you wish to hang your box. Slide the overhanging 1/2" of your side pieces over the 2x6, and use 3-inch screws to fasten the sides to the 2x6.
Step 10: Plant Window Box

Kamron and Ellie Sanders

Kamron and Ellie Sanders
Start with a layer of landscape fabric to help protect the window box. Then add soil and a diverse mix of bright flowers, waxy greens and flowy foliage to bring new life to your home's exterior.