DIY Network

How to Build an Attached Greenhouse

This attached greenhouse can be assembled in one weekend.

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wire top benches and wire shelves are installed

Step 1: Attach the Front Sill and Side Walls

Once the end-walls are assembled, the front sill is attached to the concrete foundation.

The side walls are then attached to the house, followed by a ledger — or upper ridge — that's fastened to the house.

attach front sill and side walls

Step 2: Unpack the Parts, Assemble the End Walls

After unpacking the parts from the shipping crates, and conducting a parts inventory, the assembly begins with assembling the end-walls of the structure. These walls are the easiest elements to assemble. The parts are bolted together with ordinary bolts that fit in pre-drilled holes in the tracks of the aluminum frame.

unpack parts, assemble end walls

Step 3: Install Ribs and Frame Roof

Once the two end walls, ledger and sill are all in place, the ribs of the structure can be installed.

Once the ribs are installed, a horizontal truss that bears much of the weight of the roof framing is added. A light, thin extrusion is used for the frame of the structure to minimize shadows in the greenhouse interior.

ribs of structure are installed

Step 4: Enclose Frame

With the skeleton of the structure complete, the next step is to install the lightweight polycarbonate panels that enclose the structure (Image 1). These translucent panels are held on the structure with double-sided glazing tape. The panels are then secured with an aluminum cap on the outside. The polycarbonate panels (Image 2) are lighter than glass, and are durable and sturdy. They also provide some insulation to conserve some of the warmth generated by the sunlight. They are designed to diffuse the light as it passes through, so the light won't burn the plants inside.

Step 5: Install Vents

Having completed the basic structure, the roof-vents, side-vents and vent-controls can be added.

vents are added to basic structure

Step 6: Install Benches and Shelves

Wire-top benches and wire shelves are installed inside the greenhouse. These surfaces are popular in greenhouses since they don't collect dirt, and they allow light to pass through to any plants placed underneath.

wire top benches and wire shelves are installed

Step 7: Wire Circuits

As far as electricity, a single 15-amp circuit supplies power to an electric heater, and another supplies power to the lights and accessories.

The top and side vents are designed to open and close automatically — without electricity. They incorporate thermal pistons that open and close the vents based on temperature. The piston contains a thermal wax that expands when it heats up from the sun. The expansion drives a piston rod that pushes the vent open. In the evenings, as the wax cools, it shrinks, and the vent closes.

15 amp circuit supplies power to accessories