How to Build a Greenhouse with Old Windows and Doors

Sep 2, 2022

Have you ever wanted to grow your own fruits and vegetables, but thought it would be too expensive to build a greenhouse? Well, think again! You can easily build a greenhouse from old windows and doors for a fraction of the cost of buying one.

If you happen to be replacing old, vintage windows, hang on to them for this kind of project and put them to good use. It’s a great way to recycle materials and with just a few hours of work, you can have your very own greenhouse that will provide you with fresh produce all year round. Follow these steps and let us know how your project turns out!

1. Choose a Location

There are a few factors to consider when deciding on the best location to build a greenhouse. The most important factor is sunlight. Greenhouses need direct sunlight in order to function properly.

Another important factor is wind protection. Greenhouses should be built in a location that is sheltered from strong winds, especially if you live in a climate with harsh winters.

The third factor to consider is that greenhouses should be built on sturdy ground with well-drained soil in order to prevent waterlogging. You need to check regularly to see that the draining holes are clear and unobstructed.

Ventilation is also very important, and one of the best and most practical ways to do that is to install the top row of windows with top-side hinges so they can be propped open. Consider installing an automatic watering system that will help regulate the amount of water in your greenhouse.

Finally, be sure to monitor the soil moisture levels in your greenhouse regularly and take action to adjust the watering accordingly. By following these simple tips, you can help prevent waterlogging in your greenhouse and keep your plants healthy and happy.

2. Decide on a Design Style and Roofline

You can make your greenhouse as simple or elaborate as you like. Choosing the right design for your needs, and with a little bit of planning, you can create the perfect environment for your plants to thrive.

Draw up plans.

Draft each window square to scale and then they will fit together like a puzzle when it comes time to build. Measure your windows from edge to edge and organize your windows in stacks based on the same size. You’ll also want to clean the windows and remove any hardware such as handles or locks.

Think about the size and shape of your greenhouse.

How much space do you have to work with? Make sure that the greenhouse you choose is the right size for your needs. Having a sloped roof is a good choice because it’s easy to plan, purchase the necessary materials, and construct, as it doesn’t require a roof cap.

What types of plants or crops do you want to grow?

Different plants have different requirements in terms of temperature, humidity, and light. Make sure that the greenhouse you choose can accommodate the specific needs of your plants. Greenhouses are particularly well-suited to delicate plants that need a warm, stable environment where you can control the temperature and humidity levels inside the greenhouse very precisely.

Consider the climate in your area.

If you live in a place with a lot of rain or snow, you’ll need a greenhouse that can withstand those conditions. Conversely, if you live in a very hot and sunny climate, you’ll need a greenhouse that can keep your plants cool and protected from the harsh sun.

Take into account your budget.

Greenhouses can vary significantly in price, so it’s important to find one that fits your financial needs. That’s why your treasure hunt for vintage windows and doors can pay off big time in the long run, because they can be acquired at a minimum cost.

3. Prepare the Foundation

Clear an area so that it’s level. If you think that you might want to move your greenhouse to a different location sometime in the future, you don’t have to put in a permanent foundation. You can dig in the corners and place cinder blocks for the greenhouse foundation. This is to make sure everything is secure, stable, and level.

4. Select Your Materials

Once you’ve selected the perfect location for your greenhouse and leveled your foundation, it’s time to start gathering materials. As mentioned before, you will need old windows and doors for this project. You can usually find them for free or at a very reasonable price at vintage shops, thrift stores, garage sales, Facebook Marketplace, salvage yards, and even flea markets.

Recommended Supplies:

  • old windows and doors (enough to cover the desired area of your greenhouse)
    2×4 and 2×6 boards of treated lumber for the frame (8, 14, 12, and 10-foot long pieces recommended for a rectangle shape)
  • tubes of Caulk
  • cinder blocks
  • 3 inch wood screws for treated wood
  • roofing screws
  • thread bar
  • polycarbonate corrugated, clear roofing sheets
  • window hinges
  • window hook-and-eye latches
  • window handles
  • metal tie down angle brackets for roof
  • metal tie down (hurricane) brackets
  • 2-3 gallons of outdoor paint
  • nails, hammer, saw

5. Building the Frame

Once you have all of your materials gathered, you can start building the frame of your greenhouse. It’s fairly straightforward, but it never hurts to consult a professional, or watch video tutorials from respected sources.

  • Secure the boards together with 3 inch wood screws to form a rectangular or square shape, with the corners meeting over the buried cinder blocks.
  • Drill a hole about 3-foot from each corner and 1 inch from the inside edge of the frame. Hammer the metal thread bars through these holes to anchor the frame into the ground.
  • Secure boards upright in the corners as studs and reinforce with a shorter board on top and bottom of each stud, (a method called toenailing), as this will also help provide extra wood to attach the windows.

Adding the Windows and Doors

  • Start attaching the windows and doors to the frame and studs with the 3-inch wood screws. First, create an L-shape in each corner for stability and ease, as you add more studs between each section of windows.
  • Install the top windows with hinges on the top side to allow them to be opened out for ventilation on hot days.
  • Hang your door on its hinges and add a handle, if needed.

Installing the Roof

The most common type of roof is the clear polycarbonate roof, which allows sunlight to pass through while still providing protection from the elements. This creates the optimal growing environment for your plants.

Building the Rafters

This is a relatively simple process, but there are a few things you need to keep in mind. First, you’ll need to determine the length and width of your greenhouse. Once you have those measurements, you can cut the lumber to size and assemble the rafters.

To make sure your greenhouse is sturdy, use screws or bolts to secure the rafters to the greenhouse frame. Space them evenly. It’s also a good idea to add some cross-bracing between the rafters for additional support. Again, it is recommended to consult a professional to ensure structural safety.

Adding the Roofing Sheets

Once you have the basic framework of your greenhouse and rafters in place, you can start adding the roofing sheets.

  • Measure the width and length of your greenhouse. This will help you determine how many sheets of roofing material you’ll need.
  • Cut the roofing sheets to size using a sharp knife or power saw. Make sure the cuts are straight and even.
  • Attach them to the greenhouse frame. Use screws or nails to secure the sheets in place.
  • Seal the edges of the roofing sheets with silicone caulk or another type of sealant. This will help prevent leaks and drafts.

Follow these tips and you’ll be able to add roofing sheets to your greenhouse with ease. Doing so will allow you to extend the growing season and protect your plants from the elements.

6. Finishing Touches

Now, you just need to add some finishing touches. You may want to caulk around the windows and doors to help seal in the heat. You can also add shelves or plant hangers inside the greenhouse so that you can start growing plants right away. If you make your greenhouse tall enough, you can have high shelves. Make sure you have enough space for the plants you want to grow. Some plants, like tomatoes, can get quite large and will need plenty of room.

One of the great things about greenhouses is that you can grow a wide variety of plants, even those that wouldn’t normally thrive in your climate. Some of the most popular plants ideal for greenhouse growing are tomatoes, peppers, cucumbers, eggplants, lettuce, and spinach.

Provide adequate ventilation to prevent problems with mold and mildew, and keep an eye out for pests and diseases, as cucumbers and tomatoes are especially susceptible to both.

7. Safety Tips

Safety is important when working with old windows and doors.

  • Wear gloves and safety glasses to protect yourself from sharp edges.
  • You should use a dust mask to avoid inhaling any dust or particles.
  • Wear a safety helmet or hard hat. You don’t want to catch a beam or window corner in the head.

Always test for levels of lead in old paint.

A greenhouse can be a great addition to any home, providing a place to grow plants and vegetables all year long. Greenhouses are perfect for starting seeds or growing delicate plants that need extra protection from the elements. No matter what plants you choose, with a little care and attention, you can grow just about anything in your greenhouse. So get out there and start planting!

SoCo Wood and Windows is here for you from start to finish for all your window and door-related projects. Our experts are ready to see that every aspect is simple, efficient, and easy. When it comes time to replace those old windows and doors, consult with our pros.