Base Size & Preparation

Check out our handy tips for greenhouse base preparation and the recommended minimum dimensions for your base area.

Preparing an area for your new greenhouse can be a pretty simple task once you know the most recommended location to site it in the garden, and the different types of base options that you can use, depending on your preference.

Whether it be straight onto grass or gravel or installed onto a pre-prepared concrete or slabbed area, there's not really a right or wrong place for your greenhouse to be placed as long as a few things key points are considered.

Top Tips for Greenhouse Base Preparation

  • The area should be level, flat, and hardstanding. Recommended areas to site a greenhouse include:- On an area with a concrete slab base.- On an area with cemented paving slabs or patio bricks.- On grass or gravel where the ground is completely level and flat, firm, free-draining, and not prone to flooding.
  • Ensure that your chosen area is large enough to site your greenhouse. You can find the correct recommended base dimensions by using our handy diagrams below.
  • Choose an area for your greenhouse that is free from obstructions such as not under trees or power lines, or on top of manhole covers or drains.
  • Choose an area for your greenhouse that has a minimum clearance of 2-feet of free space/access around all sides, so that the greenhouse sections can be maneuvered around the installation area where required.
  • Choose an area for your greenhouse that has natural windproofing nearby, such as hedges, fencing, a wall, or similar. It is not advisable to site a greenhouse in the middle of a large, open area.

Benefits of a Base Plinth Accessory

Most of our greenhouses and wall gardens can be purchased with an optional, matching-size base plinth. These are metal plinths that raise the greenhouse up off the ground and provide a sturdy plinth for the greenhouse to be installed on top of.

Base plinths come with anchor spikes for each corner as standard, which are designed to be used when installing onto soft ground such as gravel, soil, or gravel, as the anchor spikes can be sunken into the ground (and potentially cemented into place) to anchor both the plinth and the greenhouse into place. This provides an exceptionally rugged way of keeping your greenhouse structure secure.

Alternatively, if you are installing your greenhouse onto a hard surface such as a cement base, paving slabs, or patio bricks then the corner spikes are not necessary, and the base plinth is simply bolted straight down onto your prepared solid surface. This ensures a safe and secure anchoring of both the plinth and the greenhouse to your base area.

Additionally, a base plinth increases the overall height of the greenhouse by 12.8cm (5 inches), meaning more internal vertical growing space - perfect for tall vine plants such as tomatoes and green beans.

An example of greenhouse base plinths.
An example of greenhouse base plinths.

Recommended Base Sizes

We've created a collection of handy diagrams to easily find out the minimum recommended base/area sizes for greenhouse models within the Halls greenhouse range.

For Halls traditional greenhouse ranges including Popular, Supreme, Magnum and Qube -
➡️See our base size guide here.

For Halls Cotswold greenhouses including Birdlip, Burford and Blockley -
➡️See our base size guide here.

An example of greenhouse base areas, timber and concrete.
An example of greenhouse base areas, timber and concrete.

Additional Weatherproofing

Greenhouses are not designed to be 100% weatherproof. As per their structure, there may be small gaps in the frame where rainwater can seep inside, however, this is not classed as a manufacturing fault, nor an installation fault and is completely normal for a greenhouse.

You may choose to complete additional weatherproofing such as using an outdoor, weatherproof silicone sealant (similar to what's used around bathtubs and sinks) to bind the joins where the glazing and the frame meet in order to further aid its durability and to reduce water ingress.