Our decision to build a greenhouse was years in the dreaming. Then one day, we just decided to do it. We were ready. Our tomato plants were begging to be let outside but it was still too cold for them. It was a race against time as we prepared the site and foundation. Fortunately, we were in between snowfalls during this time. In Calgary, you have to be prepared for spring blizzards…they do happen. You’ll notice that when we started the site prep, there was no snow anywhere. And then there was!
How we built our greenhouse
First, a plan
Since my father had his career as a draftsman, I learned from a VERY young age that in order to build anything, you need to make a plan. So, make a plan, I did. I am proud to say, that my plan is to scale and accurate to within a few inches. This is how I planned the wheelbarrow pathways and raspberry transplants etc. This is also the reason you will later see part of the garden beds hacked off. We needed to rearrange some stuff!
This is also the time to check with the city regarding any permits you might need.
Type of greenhouse
We knew the type of greenhouse we wanted would be a smallish footprint in size. The two biggest factors for this were our available space, and also our budget. We decided to go with an aluminum type kit that we purchased from a local garden center (see below for resources). We really liked the curvy design of the frame, which would also allow for more headspace inside.
Based on our number of sunny days in Calgary, we chose polycarbonate siding instead of glass for this project. It diffuses the sun which prevents the scorching of plants inside. For those who live in cloudy, rainy climates, glass would be my material of choice.
Site location and prep
We chose our site location carefully. It is sheltered on two sides by our fence; an important consideration on windy days. We chose the northwest part of our yard. You may also notice from the picture that we had to adjust a couple of our garden beds to make room for the new greenhouse. Don’t worry, that will be a garden bed once more, but one thing at a time.
This foundation isn’t going anywhere. It has 24″ of rebar all the way around, anchoring the frame to the ground securely. Tip: do not rush this step. This frame must be absolutely square- and level.
Once the ground was level inside, we used landscape fabric, small gravel, and sand to ensure excellent drainage and weed prevention. We decided to go with bricks for a couple of reasons: One, we already had some from a previous project and wanted to use them up. We planned out a design schematic that reduced the cutting of bricks. Third, in cooler weather, the bricks will help retain more heat.
Some of you might be wondering why we have a rain barrel inside the greenhouse. Ideally, this would have been a black one- to draw in and hold more heat during the cooler nights. We actually have a small heating element hooked up to this (the weight is holding it in place). There is also an automatic vent that opens and closes according to temperatures. The piston is made with wax, so when it gets hot, the wax expands and opens up the vent. When it cools down outside, so does the wax, and magically the vent closes again. We also purchased an additional stationary vent (not yet installed) which allows greater circulation and heat release during the really hot days- because we get those, too.
Since it has snowed recently, we also have an additional electric heater that is on a thermostat. I don’t really want to see our next electric bill…
You also can get a small sense of the custom shelving that Clint built here. We decided to build them in staggering heights in order to accommodate larger plants on one side, and then two layers of shelving for smaller sized plants. We can store compost and buckets and pots etc on the ground level.
We made use of some very good books to get ideas. I’ve recommended them below.
Green house project costs
We haven’t added up all the receipts yet, but we estimate this project came in around $1,700 CAD, based on the materials we used. I might come back and revisit this in more detail later.
Awesome greenhouse websites and resources
We are SO glad we went ahead with this project. We consider it to be an investment of both our energy and resources. We have learned so much already, and can’t wait to make full use of our little greenhouse.
Before you go
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Until next time,