How to Build a Garden Shed Addition
Plenty of storage for outdoor tools and toys, only a step away from your back door
By the DIY experts of The Family Handyman Magazine
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Time Multi-day Complexity Complex Cost Over $500
Click the links below to download the construction drawings and material list for the 2000 shed.
Spacious interior storage
This shed measures 7-1/2-ft. x 13-ft., giving you about 100 sq.ft. of storage space.
Build in shelving for all those little items. The windows bring in a flood of light.
Sliding door access
The sliding door opens wide enough for wheelbarrows to roll through.
Even though we’ve engineered this shed to keep complicated figuring and cutting to a minimum, it’s still a big construction project that will take you at least five or six weekends to complete. If you’ve built a deck or similar structure, you’ll have no trouble putting in the foundation and building the walls. To help you through the trickier roof-framing stage, we’ll show you how to make a rafter pattern without using any complex math. You may have to modify our plans slightly to fit your house, but all the basic building techniques we show will be the same.
You won’t need any special tools for this project. You probably already own most of the basic carpentry tools you’ll need to build this shed. Besides hand tools like a hammer, tape measure, square, utility knife, chalk line, sharp chisel, handsaw and a few screwdrivers, you’ll need a 4-ft. level, a line level (Photo 2) and a power drill, plus the bits listed in the story. A circular saw will work for most of the cutting, but the windowsill and drip cap (Fig. C) require bevel cuts that would be easier to make with a table saw. If you don’t own a table saw, ask a woodworker or a full-service lumberyard to cut these pieces for you. A power miter box is another optional tool that would add speed and accuracy to your cutting, especially for finish work. You can rent a power miter box, but for a project this big, I’d recommend buying one.
Step 1: Pick a site and order materials
Shed added to garage
We extended our garage roof to cover the shed as well. But you can also butt the shed roof into a garage wall.
Scope out the perfect location.
With its simple roof style, this shed can go just about anywhere. Look for a spot on the back of your house where windows and doors aren’t in the way. Behind or to the side of the garage is a good location. We tied our shed roof into the garage roof, but you can also butt the shed roof against a wall, as long as you install metal flashing under the siding and over the shingles where the roof and wall intersect.
In addition, consider: Ground level. The ideal site is flat and sloping slightly away from the house. If the ground slopes steeply, either toward or away from the house, your job will be a lot harder. You’ll have to excavate and build retaining walls or bring in fill. In any case, regrade around the shed to ensure good every drainage and provide a ramp for your lawn mower and wheelbarrow. Roof pitch and headroom. This is the trickiest stage of planning. Our garage has 9-ft. tall walls and a shallow pitched roof. This combination allowed us to continue the roof in a straight line and still have enough headroom at the outside shed wall for standard-height windows and doors. But your house/garage might be different. To ensure adequate outer wall height, stretch a string along the roof and brace a 2×4 temporarily at the location of the outside wall to figure out how much headroom you’ll have (basically the same procedure shown in Photo 9 for making the rafter template). Measure from the string representing the roof down to what will be the top of the 6×6 foundation beam. If this distance isn’t 90-3/4 in., you’ll have to modify the wall height or change the roof slope of our shed plan.
Then call your local building inspections department to find out if your shed location is OK and what’s required to get a building permit. Most cities will accept a plan drawn to scale on 1/4-in. graph paper if it includes all the structural details.
Every region has a few unique building requirements. In cold Northern climates like ours, deep footings are required to prevent frost heaving. In areas with high winds or earthquakes, you’ll need special metal framing anchors to tie everything together. Ask your building inspector what’s required in your area.
Most of the materials for this shed are available at home centers and lumberyards. For a complete shopping list is in the Additional Information below. Here are a few pointers for your shopping trip:
- Pick straight, dry cedar 4x4s. Bowed or twisted lumber will cause trouble when it comes time to install the windows and door. Check at both lumberyards and home centers.
- Make sure the 6x6s are .60 treated, not the less durable .40 that’s sometimes used for landscaping timbers. You’ll probably have to order them.
- Barn sashes are sold at some home centers and farm-supply retailers. If you’re willing to modify the plan dimensions, cons >
Figure A: Framing Details
Note: You can download Figure A and enlarge it from the Additional Information below.
Figure B: Foundation Plan
Note: You can download Figure B and enlarge it from the Additional Information below.