How to Build a Greenhouse (with Pictures)

2024 Author: Samantha Chapman | [email protected]. Last modified: 2023-12-17 09:13

A greenhouse is a structure that maintains an ideal microclimate for plant growth. It can be used to house plants for the duration of their life or even just for their reproduction and multiplication. Building a greenhouse is a challenging project; however, it can be accomplished economically or perhaps by relying on professional builders.

Steps

Part 1 of 6: Choosing a Location

Step 1. Choose an area facing south

The first requirement for a greenhouse is to be exposed abundantly to the sun on a constant basis.

All structures should be located north of the greenhouse.
A rather common form of construction for greenhouses is that leaning against another building. In this case it is good to choose a wall facing south.

Step 2. Locations that are exposed to the sun in the morning rather than the evening are preferable

The best option is always to have the sun all day, but if this is not possible, exposure to the morning sun is more conducive to plant growth.

If there are trees or shrubs near the greenhouse, make sure they don't shade the greenhouse until late afternoon

Step 3. Consider winter sunshine versus summer sunshine

If the east-facing area is open and sunny, it will receive better sunshine in the months from November to February.

The sun's rays are less inclined in winter, so trees, houses and other structures can cause more shade problems.
Do not choose a location near evergreen trees. Deciduous trees lose their leaves and provide less shade in winter, when the greenhouse needs the most sun.

Step 4. Choose a location where electricity is available

Many greenhouses require heating and ventilation to maintain the optimum temperature.

If you build a greenhouse close to a house, you can get the energy you need by means of an extension of the house's electrical system.
Installing an electrical system in a separate building may require the intervention of an electrician.

Step 5. Choose an area that has good drainage

You will need to drain the excess rainwater.

If the soil in your chosen area has dips, you will likely need to fill them in to improve drainage.
You can install cisterns to collect rainwater from the greenhouse roof. Any form of savings in water and energy supply contributes to reducing the operating costs of the greenhouse.

Part 2 of 6: Choosing the Type of Facility

Step 1. Measure the available space

Whether you decide to build your greenhouse from scratch or with the help of an assembly kit, choose the dimensions carefully.

The larger the greenhouse, the higher the costs for construction and heating will be.
Greenhouses are easily found in assembly kits with dimensions of 2x3x1, 8 m, or 3x6x1, 8 m.

Step 2. Choose a kit greenhouse if you have little experience in construction or if you don't have someone to help you

You can buy a small kit made of polycarbonate greenhouse in DIY stores or online on Amazon or eBay, starting at just over € 60.
You can find larger and more robust models from € 450 upwards, depending on the size.
In addition to generic websites, you can look at the sites of chains specializing in the sale of materials such as Leroy Merlin.

Step 3. Build a wall greenhouse

If you have chosen an area adjacent to a building, you can build a simple structure against a wall.

If the wall is brick or concrete, the heat from the building itself can help maintain a constant warmth.
This is a very simple structure, which you can make yourself. You can build it with iron rods, tubulars, wooden beams; in general it will need fewer supporting elements than a freestanding construction.

Step 4. Build a tunnel greenhouse

This is a type of greenhouse with a tunnel roof, which can be built with steel supports or PVC pipes.

The tunnel shape means less space available in height and a reduced storage capacity compared to rectangular models.
This type can be built with little expense; however, the cheapest materials are also generally the least robust.

Step 5. Choose a rigid structure

For this type you will need to make a foundation and a supporting structure. Unless you are a building design expert, we recommend that you commission the project to a specialist or delegate the construction to someone.

A rigid structure, made with support poles and beams, requires foundations and strong structural elements.
To build a large rigid greenhouse you will need the help of friends or professional builders.

Part 3 of 6: Choosing the Cover Material

Step 1. Use polyethylene film for greenhouses, treated for UV rays

The light transmission is similar to that of glass, but it is light and inexpensive.

The plastic film must be renewed after a few years.
It needs to be washed from time to time.
It does not retain heat as well as glass, but it is suitable for wall, tunnel, and even small rigid greenhouses.

Step 2. Use double-walled rigid plastic material

The polycarbonate lends itself to being slightly curved and allows energy savings of up to 30% thanks to the double wall.
It typically lets 80% of the light through.

Step 3. Choose the fiberglass

If you intend to build a rigid greenhouse, you can save money by using fiberglass instead of glass.

Choose clear fiberglass.
You will need to restore the resin cover every 10-15 years.
Prefer high quality fiberglass. Light transmission is much lower in the case of low quality light.

Step 4. Choose the glass

This is the most beautiful material to look at if you intend to build a greenhouse that has to decorate your home or garden.

Glass is very fragile and repairs are expensive.
You must necessarily build a rigid structure greenhouse with a foundation.
Tempered glass is preferable because it is more resistant than ordinary glass.
If you intend to pay for the installation of a glass greenhouse, we recommend that you ask for offers from specialized builders to ensure that the foundation and structure are adequate to support the weight.

Part 4 of 6: Building the Structure

Step 1. Stretch some threads on the ground to measure the position of the supports

Plant stakes in the ground.

Step 2. Make iron rod reinforcements

If you are building a wall greenhouse or a tunnel greenhouse, you can create the structure with rod and PVC.

Plant the rods in the ground at a regular distance of 120 cm. Let it protrude about 120 cm.
Once the rods are in place, make side-to-side arches with 6m lengths of PVC pipe. Spread the polyester sheet over the arched structure and attach it to the bottom joists.

Step 3. Pour some gravel onto the ground to form a homogeneous layer, after planting the supports in the ground

The use of well-dissolved fine gravel promotes excellent drainage of the greenhouse.

If you need foundations, have bricklayers do the work. They will put up some formwork and cast a pour for the greenhouse flooring before we can move on to building the structure

Step 4. Apply a protective treatment to all wooden parts before installing them

Untreated wood rots within 3 years.
Choose carefully the type of treatment for the wooden parts. The use of certain products for the treatment does not allow the food produced to be considered "organic", due to the chemical compounds they contain.
Some wood treatment products are specifically designed to reduce leaching. Leaching is the process by which the soluble elements of the soil, due to the flow and percolation of the water, are transported or migrate into the deeper layers.
Better to prefer metal support elements rather than wooden ones.

Step 5. Seal the cover onto the structure as best as possible

In the case of the plastic film you can fix it to the wood with bolts.

The more expensive the roofing material is, the more care you will have to put into sealing the connections of the roofing with the foundations and the supporting structure.
Find out about the best way to apply your chosen coverage.

Part 5 of 6: Check the Temperature

Step 1. Place fans in the corners of the greenhouse

Arrange them diagonally.

They should be switched on almost always throughout the winter, to ensure the uniformity of the temperature throughout the greenhouse

Step 2. Install vents in the greenhouse ceiling

You can also place them near the top of the supports.

A certain degree of carbon dioxide ventilation is essential.
The vents should be adjustable. You will need to open them more in the summer months.

Step 3. Consider installing an electric heating system

Depending on the climate, exposure to sunlight can contribute to warming by as little as 25%. In these cases some form of additional heating is essential.

You can also use a wood or kerosene stove, but this solution requires the installation of a chimney to ensure good air quality.
It is advisable to contact the municipal technical office to check which types of heating are allowed in your area.

Step 4. Install an air conditioning system if yours is a glass-walled greenhouse

If you can afford to install a temperature control system, you can grow almost anything.

Have the system installed by a professional electrician.
The system will require regular maintenance to ensure ventilation and heating throughout the winter.

Step 5. Install thermometers or thermostats

Install more than one thermometer in case one fails.

Place them at different heights in the greenhouse.
You can install a thermometer that transmits the temperature measurement to a display inside the house, so you can comfortably keep an eye on the temperature of the greenhouse in the winter months.

Part 6 of 6: Further Design

Step 1. Study the environmental conditions required by the plants you intend to grow

The more sensitive a species is to temperature and humidity conditions, the less likely it is to grow other species in the same area.

A cold greenhouse is a greenhouse intended to prevent plants from freezing. It is ideal as a temporary protection.
A warm greenhouse is a greenhouse suitable for housing tropical plants.
Choose the desired temperature and keep it constant. It is not possible to create zones with different temperatures between them except by installing separation walls.