How To Build A Glass Greenhouse

For attractiveness, the glass greenhouse is the most popular style of greenhouse. The commonest garden greenhouse size is 8 by 6 feet or 2.4 by 1.8 meters. This size allows gardeners all the advantages of a garden greenhouse without taking up too much space or being too expensive. However, glass greenhouses can be expensive, for this reason, many people who decide to make a small glass greenhouse of this size decide to make their own using recycled or new materials.

Whether you use new glass or recycled windows for your glass greenhouse, the fundamentals of planning and design are the same. The location is just as important as construction quality when it comes to growing results.

Location, Location, Location

Your greenhouse should be positioned for maximum sun exposure throughout the day. However, due to trees and neighbouring properties, this is not always possible. In this case, your greenhouse should aim to get the most morning sunlight possible, likewise the earliest spring sunlight. Plants which get a good dose of sunlight energy early in the day and early in the year will continue to use this energy throughout the day and season. Naturally, other practicalities such as access and drainage should be considered. There’s no point having a perfectly placed greenhouse if you can’t use it.

Laying the Foundations

Some store bought greenhouses come with a base made out of treated wood, however a permanent foundation is always better if you know the greenhouse is staying put. Poured concrete or brick is the best option for the frame as this will keep the structure stable and level for years to come. Drive in posts before you pour to offer extra support and security in bad weather. However, for flooring inside the greenhouse, there is only one way to go. Gravel is ideal for greenhouse flooring as it provides traction and drainage. It can also be sprayed with water on hot days to create humidity in the greenhouse.

How To Build A Glass Greenhouse

Building a Structure

There are many good greenhouse designs online that allow you to create your own frame and insert and fix new glass panes. However, if you decide to create your own design this is also easily done, just remember a few key points. It’s easiest and safest way to make your four wall frames on the flat first and to raise them into place. Once up, a roof can be constructed using rafters. Each rafter should have a 60-degree angle cut to the lower end and a 30-degree angle cut to the top to create the A-frame of the roof.

Glazing the Greenhouse


Once the structure is up the glass can go in. You can set the glass while the frames are still separate but the risk of damage while constructing the greenhouse is greater. If you can cut glass you can also use recycled glass at this point. Cut the plates to fit exactly and put in place with putty. However, this must be done during a period of guaranteed sunshine, otherwise the putty with bloat in the rain. Tempered glass is preferable, but avoid glass that is designed to filter out sunlight.

Creating your own glass greenhouse is an ambitious project, but if you already have good woodworking and DIY skills, it is possible.