How to Build a Greenhouse for Under $100

Building a greenhouse for under $100 is a challenge; however, if the size is kept reasonable, it is a doable project. In order to keep costs down, we will use 2-inch by 2-inch framing material rather than 2-inch by 4-inch (with the exception of the base) and build the greenhouse 8 feet by 4 feet.

Hammer

Square

Level

Saw

Stepladder

Heavy duty stapler

2-inch by 4-inch framing studs (3)

2-inch by 2-inch framing studs (16)

1 box of 2 1/2-inch galvanized nails

2 self-closing nickel hinges

Door handle and latch

224 square feet of UV-resistant polythene sheeting

Select a site with good winter sun exposure. Level the site. Costs can be kept down by not using anything for flooring. If you can access free pea-sized gravel, that would work well for a floor.

Cut one of the three 2-inch by 4-inch studs in half; these are the bases of the end walls. Placing the studs on their sides so the 4-inch dimensions are vertical, nail the 8-foot studs to the 4-foot studs at the corners, forming the base of the greenhouse.

Build your side walls. Cut 3 inches off of two of the 2-inch by 2-inch studs. These will be the top of your side walls. Nail 2-inch by 2-inch studs to each end of the shortened 2-by-2 so that the length of the top rail remains 93 inches long. Nail another 2-by-2 in the middle, creating a giant 'E' shape with the open end facing down. Repeat this for the second side wall. The side wall frame should fit inside the base frame. After you double check to make sure the walls are square, attach them to the inside corners of the base and in the middle.

Create the back wall. The distance between the two side walls should be 42 inches. Cut a 42-inch piece of 2-inch by 2-inch stud and attach it to both side walls at the top, thus forming the back wall. Repeat this at the front; however, attach 2-by-2s 91 inches long to the front ends of the side walls. This is to accommodate your door.

Using the second half of 2-inch by 2-inch stud left from the back wall, cut it in half and attach the piece in the center of the front and back cross members. Then attach a 2-inch by 2-inch stud 8 feet long to the top of the upright 2-by-2s. This will create the peak of your roof.

Build your door. The distance between the two pieces you attached to the front of the side walls should be 45 inches. Cut two 42-inch 2-inch by 2-inch pieces for the top and bottom of your door. Cut two 2-by-2s 91 inches long. Nail the 42-inch pieces to the 91-inch piece at the top and bottom, making sure the short pieces are inside the longer ones. For extra strength, cut a diagonal piece to run from the top left-hand corner to the bottom right-hand corner of the door. Fix the door to the frame with two nickel self-closing hinges and attach the latch and handle.

Attach the polythene sheeting to the framework. Start at the top, cutting a piece large enough to form the roof without seams, and staple it to the frame, making certain to stretch it tightly. Do the same to the side walls, back wall and door.