Build a Greenhouse
Expert Advice

During the pandemic many looked for ways to upgrade their home and spend more time in their backyards, This became known as “backyarding” and one concept that rose in popularity was a renewed demand from homeowners to build a greenhouse. The primary reason cited was the ability to ‘grow your own” fruits, vegetables, or plants.  If you think you want to build a greenhouse, but don’t know where to start, here are some answers to some of the most common questions from our friends at Hartley Botanic.

What size and type of greenhouse should I buy?

Envisioning how you would like to use and enjoy your greenhouse is a useful consideration in deciding upon a design and final size. There are several ways a greenhouse can bring your gardening potential alive and expand the way you utilize your backyard as an outdoor space. Perhaps you want your greenhouse to fulfil a dual purpose, to be a very practical tool for growing your own food but also, an alfresco room where you can sit amongst your plants.  For this, a structure which allows for a generous seating area with a view of key staging areas could be a consideration. You can hire a builder or do it yourself.

What is the optimal position in my yard for a greenhouse?

Your greenhouse needs access to as much sunlight as possible during all seasons of the year, so positioning is an important consideration. Avoid locating your greenhouse in the shadow of tall trees, boundary fences or walls as these will obstruct light. For lean-to greenhouses placed against a wall, a south-facing position is ideal. For stand-alone structures, the ridge along the top of the greenhouse should ideally run from East to West, this will allow the sun to run along its longest side during the day.

Other elemental considerations include a location to catch prevailing winds for ventilation purposes and choosing a site which is not shaded, but equally not too exposed to the cold. Build your greenhouse near an electricity and water supply, and on fertile soil if you want to install growing beds. It is also important to consider how the structure will fit aesthetically into your landscaping as a whole.

Will I need planning permits?

Planning permits are not always needed for greenhouses.  However, you should check with your municipality, county, and city in advance. There are many and varied circumstances where planning permits will be required, such as regulations from Homeowner Associations and zoning and building ordinances. Zoning permits regulate the location of greenhouses on individual properties and will govern how many accessory buildings you can have. In contrast, building codes look at the structural integrity of greenhouses in relation to your geographical location. You may also need permission if the greenhouse will be disproportionately large in relation to your existing property. 

What water access will I need?

Watering is arguably the most important daily task in the routine of owning a greenhouse, so easy access to a water supply is a must, especially during dry seasons. There are automatic watering systems available for greenhouse owners, but for domestic structures, these are not always necessary and lack the intuition and personal touch of a gardener, able to tailor watering according to each plants’ needs.

How do I ventilate my Greenhouse?

One of the most common reasons for plant failure in greenhouses is due to insufficient ventilation. You need to maximize the ventilation, and the number and position of your vents according to the specific needs of your structure and what you are planning to grow.  Some greenhouses come with automatic roof vents and other models come with manual ventilation.

Is an electricity supply essential?

Running an electricity supply directly to your greenhouse is not essential, but it can certainly make your life easier and your greenhouse more efficient. Both heat and light are wonder ingredients for your flourishing plants and can be exploited further if available in all seasons and at all times of day or night. Lights give you the chance to extend your time in your greenhouse by improving visibility and can encourage growth. Fan heaters are very efficient at circulating heat, even in medium and large structures.

How much should I spend?

This really depends on the type of greenhouse you would like, and its size and scope. When considering the size of your greenhouse, weighed against its potential cost, it is important to consider how long you are likely to be using it as a growing space and how your needs may change over time.  If practical within your backyard and budget, a larger structure provides more scope to meet your future growing ambitions, which are likely to increase, especially if you are a first-time greenhouse owner. Clearly, if considering a larger structure, final budget considerations should include potential heating and lighting costs.

Now that you know everything you need about how to build a greenhouse, what are you waiting for?