DIY Greenhouse Garden Shed Made with Old Windows

DIY greenhouse garden shed made with recycled windows! Learn how to build a sustainable, budget-friendly space for your plants.

We built a cozy greenhouse garden shed in our backyard and I want to inspire you to make your own greenhouse structure! This DIY project uses recycled windows to create a cozy inviting space for your greenery to thrive. 

Not only is it a beautiful greenhouse, but it’s also a great way to save money and add a touch of charm to your outdoor space. Let’s get started!

plan your DIY window greenhouse

The first step to planning any DIY project is to plan. I’ve been planning this greenhouse garden shed for about ten years. 

When one of our daughters and her family upgraded the 1963 windows in their home, we knew we would have enough windows for this DIY greenhouse project! I also had a stack of antique windows that I had been collecting for some time. 

choosing the right location

The ideal location was the easiest part of this entire project. We have a row of white crape myrtles in our backyard with a curly willow tree. Between the crapes and the willow is an empty spot directly in front of a row of Korean lilacs.  

It was the perfect spot for this garden shed that I will use as a potting shed as well as a greenhouse!

design and layout considerations

The design of this greenhouse build depended completely on the windows. We had twenty window sections from our daughter’s home so I could have ten window sections on each side wall.

The additional mismatched antique windows would go on the structure’s front and back.

Let me mention that the 1963 windows were sash windows. We took them apart and turned them on their side so that they were tall and narrow instead of wide and short.

You’ll see in the images what I mean! The largest window measured about 23″ wide and 36″ tall.

​local building codes

Check with your local building codes to ensure you comply with the local standards. If need be, you may have to hire out some of the work.

thanks for being here!

I hope you are enjoying this project! Let me know if you have any questions. Or leave me a comment to tell me about your project and ideas!

thanks, Cindy 😀

Tap here to comment!

collecting building materials

As I mentioned, I’ve been gathering supplies and ideas for a long time. If you are interested in building this type of project, start planning, dreaming and collecting your supplies now! 

sourcing old windows and doors

Look at auctions, estate sales, and yard sales for building materials you could use. 

Pass the word out to your family and friends that you want to build a little greenhouse and you might come across someone upgrading their own windows. They would love to give them to you! 

Facebook Marketplace is a great place to shop for supplies like old windows, leftover lumber, storm windows, french doors, and other building supplies.

selecting additional construction materials

Once you have enough windows, a door, and any other available materials, it’s time to think about new materials. This is the time to draw out your plan.

I began by drawing out several wall plans on graph paper. It took many tries but using the measurements of the windows I had collected, I drew the two side greenhouse walls, the front of the greenhouse and the back wall including the size of the windows in the drawings.

My hubby then took my drawing and calculated the new lumber material we would need for the DIY greenhouse.

BTW, this structure will also be a garden shed and a potting shed. I have many plans for this adorable little building so stay tuned and sign up for my email so you don’t miss any of the posts!

materials list

Here is a list of the new materials we purchased for this project. You will notice that I am not giving exact amounts of each supply. 

The number of boards and roofing materials will be dependent on the final size of your building. 

Ours measure 10′ wide x 12′ deep and is approx 10.5′ tall. This list is to give you an idea of what you might need for your DIY greenhouse.

The best way to plan for the new materials you need to purchase is to first collect the windows and any other materials you can get before heading to Home Depot or any other construction supply store. Having used supplies will be a fraction of the cost of buying them all new!

• 4″ x 4″  treated posts
• ​bagged concrete
• 2″ x 4″ lumber
• 1″ x 4″ lumber
• polycarbonate roof panels
• ​corrugated tin roof panels
• 4′ x 8′ sheets of T1-11 board
• pea gravel & landscape fabric
• hardware like screws, hinges, hurricane straps
• paint and stain supplies

As for tools, we used basic construction tools including a miter saw, a circular saw, a drill driver, a tape measure, a level, and a square.

treating and painting materials

It is a good idea to prep some of the materials before using them. This is a step we didn’t do and would have been easier if we had!

Paint or stain the lumber that will be used for the roof rafters, the posts, and the 2″ & 1″ x 4″ boards. Use a sawhorse setup and get this done before cutting!

It’s also a good idea to prep the windows before installing them. I scraped the old glazing from the windows and replaced it with new window glazing. This was much easier to do before installation!

the building process

You will see the process of building this DIY greenhouse in the video I created for you. I will have that video linked later in the post and it will help to give you a visual guide as we built this garden shed.

For now, I grabbed a few images for you! Be sure to pin any of the images for future reference!

building the greenhouse frame

We built this structure similar to a pole building. It does not have a cinder block or wood foundation. It is built directly on the ground. The 4″ x 4″ posts are set in concrete and provide the main frame for this building.

building the side walls 

​After digging the holes for the posts and setting them in concrete, we allowed them to cure overnight. Then we attached treated 2″ x 4″ boards around the base of the structure.

We also attached treated 2″ x 4″ boards approximately 40″ up from the ground. This helped to stabilize the frame and provided framing for the windows.

construct the roof rafters

This was the most difficult part of the whole project! There is a ton of math involved when building rafters and I won’t pretend to know enough to explain it to you. I suggest you do what we did and go to YouTube! 

Here is a video that explains the best way to figure out the rafter calculations. Hubby and I reviewed it over and over again before we started cutting and assembling the rafters. 

If you are not confident with this, I suggest you hire this part out! Your might also consider hiring someone to attach the roofing materials. This part was so hard to do and required all hands on deck. I didn’t get any images of the process nor did I get any video!

adding roofing material

​My hubby has added roofing material to previous projects and he was confident in his abilities. So we tacked it. One-third of the roof is made of clear polycarbonate panels to allow in sunlight. This section is my greenhouse.

The other two-thirds of the roof is made from corrugated tin. This section of the building is the potting shed and garden shed.

flooring options for a greenhouse project

We looked at several options for the bottom of the greenhouse. First, we priced out DIY concrete, which would cost about $350. Then we priced out treated wood. That added up to over $400!

We opted for a pea gravel floor with a landscape fabric base. This option saved us a ton of money! One load from our local landscape supply store costs only $41! The pea gravel allows for drainage too which is important for a greenhouse.

installing windows and creating ventilation

Installing the old windows was tedious to say the least. Each window we used for the side walls had a different width measurement. Fortunately, the heights were all the same. 

fitting windows into the frame

To build the window framing, we used 2″ x 4″s on the top and attached the windows to the top with hinges so that they would swing outward. Then we used scraps of wood to build out ‘stops’ on the inside of the window frame.

The windows are not airtight. If you want airtight windows, measure carefully!

The front and back walls were built using standard 2″ x 4″ framing methods to fit the antique windows and the old door.

creating air circulation

The great thing about attaching the windows with hinges at the top is that every single window swings outward. Currently, I am using little scraps of wood to hold them open but I have plans to use something more creative in the future.

We also installed simple hooks on the inside of the window frame to hold them closed.

Since all of the windows are open, we have perfect air circulation for the whole structure!

front and back greenhouse walls

As I mentioned earlier, we used standard construction methods to build the front and back walls fitting around the antique windows. Once the framing was finished we installed the 4′ x8′ sheets of T1-11 horizontally to create the look of individual board planks. 

Once it is painted, the grooves in the T1-11 sheets will stand out and make them look like separate pieces of wood.

After installing the sheets of  T1-11, we installed the windows on hinges. The antique door was repaired using wood glue and bar clamps. It was a bit of work but worth it! Hubby purchased a new piece of glass for the section that was missing.

final touches and maintenance

There are still many plans for this adorable garden shed DIY greenhouse to come! Part of the fun is collecting old pieces to use in this building. I recently recorded a YouTube video showing some of the flea market finds I purchased for this adorable potting shed.

I’m excited to use it as a three-season room especially during the flower season!!

adding interior shelves and planting areas

I will be adding shelves to hold new plants and gardening tools. The potting area will have a surface and container to hold potting soil. I’m excited to share that idea with you!

I’m also looking for shelving for the greenhouse area in the back of the garden shed. 

Several shelves will hold seed starting trays so that I have plenty of flowers for my cutting flower garden! My hubby will also have a place to start seeds for his vegetable garden.

applying protective sealers

The main structure was painted and sealed using outdoor paint leftover from our front porch concrete floor makeover. I had just enough off white paint to paint the whole interior!

Next, I will be painting the exterior and adding a creative trim to the windows and door on the front and back of the greenhouse.

​adding decorative touches

​Over the coming months, I will be adding more decorative touches to the greenhouse including wallpaper, vintage items I find like baskets and old tools, and of course, all sorts of plants!

cost of our old windows DIY greenhouse project

The cost of our DIY greenhouse will be different than yours. New materials can range in price from year to year. Also, the size of the structure will make a difference in the total cost. 

​The cost of the supplies we used was $2500 and a ton of sweat! 

garden shed interior

You are going to love what we have done to organize and decorate the interior of this garden shed! Click the button below to see the inside of this sweet greenhouse!