There are many different styles and ways to build a greenhouse for your backyard. Your decisions on how to construct, heat, cool, and maintain an overall working environment will mainly depend on your needs and what you want to get out of it. Choosing a design/frame is going to help define everything else. This is dependent on your both your interior and exterior space requirements, the look you're going for, and your budget. Small geodomes are visually interesting and are relatively simple to build, or the traditional greenhouse look may be what you're looking for. Choosing this helps decide the construction material needed.
The two main construction materials for the walls and roof are lumber or metal conduit. However, lightweight PVC piping or steel are also options, depending on your needs. Choosing which one may depend mostly on your experience and your budget. Either material is appropriate, but most homeowners are more comfortable working with lumber. After deciding on the design/frame and the construction materials to use, the next step is to set up the frame and insulation.
In addition to the construction material of the physical structure, keep in mind the flooring material too. A system that easily drains and maintains an appropriate barrier between pests and bugs is ideal. This can range poured concrete with drainage, crushed stone with weed cloth covering, bricks overlaid on sand, or weed mats.
Insulation and Greenhouse Cover Material
Depending on your needs, which is partially defined by your geographical location, you can choose several options for the insulation. The greenhouse cover material doubled as insulation and your your walls, so taking into account the harshness of the weather is important too. The two main types of greenhouse cover material are solid corrugated polycarbonate sheets or different thickness polyethylene film. The thickness will depend on the level of protection required.
Conditioning the Air and Ventilation
Conditioning the air and small greenhouse ventilation are needed in some capacity, however, just a small greenhouse ventilation system may be enough to maintain the appropriate conditions for most backyard greenhouses. At a minimum, the ability to open a window or a door and leave it open can act as a form of ventilation. However, it may be necessary to include a physical window or vent that can be opened or close while also limiting bug and water infiltration.
Overall, you want the ability to control the environmental conditions within your greenhouse. This includes a blower, heating, or cooling systems. A simple thermostat can be used to control these, however, someone can also incorporate a more intelligent system if they need to in order to more precisely maintain the environmental conditions.
The type of door you want may depend on your needs. Most backyard greenhouses will have a simple door that has the same insulating material as the walls. This is an easy go-to option. However, there are other options such as roll-up doors or simply an area where you can easily move aside the plastic insulation to gain entry and exit.
Depending on the style of the greenhouse, a guttering system may be needed. This helps maintain the integrity of the greenhouse by channeling the flow of water from rain to a specific area. Better yet, channel the water to a water tank for watering the plants.
Benching and tools are a consideration that you want to take into account when working in a greenhouse. benching allows for you to work higher on a sturdy structure so your plants can thrive. Having the tools available and placed in there is an organizational point that makes it easier for your to achieve what you'd like to. Also important are greenhouse lights. The greenhouse lights can aid in supplying light to the plants, aid in your ability to see when there is not enough ambient light, or both.
Putting It All Together
Start by laying you flooring which will be used for greenhouse. Erect the frame on top of the flooring. At this point, it may be best to include any electrical components such as lighting, fans, blowers, heating or conditioning components to the frame. Next, cover the frame and doors with the insulating materials of your choice. Finally, install any guttering system and the interior components such as benches, places for tools, and the like.