DIY: Convert A City Garden Shed Into A Small Greenhouse

Converting a worn down shed into a greenhouse can involve demolition, however planning a redesign of the existing structure should be the first consideration.

A small, unused or unneeded shed can give your plants an early start, if you convert it to a greenhouse. Basically, a shed’s bones or skeletal framework isn’t much different — if at all — from that of its warm, humid, greenhouse counterpart. And it relatively involves little undertaking and costs, but a few general guidelines can get you thinking about the transformation.

Stripping down, you’ll start your shed-to-greenhouse transformation by working backwards — undoing the build in the opposite way the structure came together. However, keep in mind that you do not have to completely rip apart the shed, in fact many of its features can be used. Yes the door likely needs to come off in order to add in new exterior-plywood walls. The existing  panels in our case were left on and we added another layer of half inch plywood, making the siding 1 inch thick in total. We removed the roofing material, but left the the wall studs, headers, roof trusses and flooring which made up the integral parts of the greenhouse’s structure. For a temporary roof we used high grade clear plastic triple layered for addition protection. The plastic was also wrapped around strips of pine 1.5 inches wide and only 1/4th in thick which created a air space to vent in summer but a space to trap heat in winter.

Today’s weather is snow and winters mix and was 19 F overnight, the indoor temp of the green house stayed at 41 F. We still have flowers and vegetables growing.

The tools you’ll need include:

   Nail puller or hammer to remove nails
   Drill or screwdriver to remove screws
   Work gloves and safety glasses

** Our shed is East  Facing** So we get sun all day within.

We replaced the old plywood door with a traditional glass pane door, added storm windows (provided for free from friends) one for each side and then added lights inside for night.

In addition we added 2 cinder block layer ( in heights ) as the lay out, in a C pattern within the greenhouse, and filled it in with cow manure. Between the soil and the walls, again we used a triple layer high density plastic to protect the walls and we used roofing cement for any potions of wood where water would be in possible contact from drainage or watering. In the end everything is sealed and water runs off out the door way, even the bottom of the door and door frames are sealed with plastic and roofing tar. Making a watertight barrier!

Contemplate your greenhouse’s layout, from the plant shelving around the perimeter to a storage area for items, such as gardening hand tools, pots, fertilizers and a watering can. We do not use a heating source, and in summer the door is left wide open for ventilation.


Top Left: Finished Project Top Right and Bottom Right are the cement block layout for the soil. Bottom Left is the almost original shed- Yes it actually was worse than this but i couldn’t locate photo. But it has no windows, no paint, and the door was a piece of plywood held on by nails.