What Size Polytunnel Do I Need?

Polytunnel Size Guide

If you’re wondering what size polytunnel you need and don’t know where to start, we're here to help.

Choosing the right size can feel overwhelming, especially with so many widths, lengths and layouts available.

Whether you’re a hobby gardener or planning your very first space as a commercial grower, this polytunnel size guide will offer tips and advice to help you make a confident choice.

The size of the polytunnel you need depends on several factors, such as your budget, available space and your ambitions.

If you don't know what size polytunnel to buy, here are some questions to ask yourself:

Where will the polytunnel live and how much space is available?

Ensure you leave sufficient space around the exterior of the polytunnel to allow for building and maintenance.

What types of crops do you want to grow?

Consider whether you'll be growing tall plants or trying vertical gardening, or growing crops that will sit at ground level and require more floor space. Explore our growing guides for detailed information on individual crops throughout the year.

What quantity of crops do you want to grow?

Is your polytunnel solely for family use, or are you growing for commercial output? This will help you determine how much you want to grow, and the length and width of polytunnel you'll need to do so.

Do you want enough space to allow for future growth?

If you want the option to grow more in the future, it may be best to size up.

How much time will you have to tend to your crops?

If you have limited time, you may prefer a small polytunnel that houses fewer plants that require less maintenance and watering. On the other hand, if you have plenty of time to tend your crops, you may wish to invest in a large polytunnel to grow greater quantities.

How much storage will you need?

Consider whether you'll need to store gardening tools, water butts, spare parts or other equipment inside, as this may help you determine the size of polytunnel you'll need.

What's your total budget?

Consider the total amount you'd like to spend and what this needs to cover. For example, you may wish to buy your polytunnel as well as accessories like growing aids, gutters and irrigation systems.

If possible, we recommend going one size bigger than you initially think, as many growers quickly fill their space with crops and equipment.

Below, we'll go into more detail about standard polytunnel sizes and which size will fit the space you have available.

What size polytunnel do I need for my garden?

Here are some standard polytunnel sizes to consider, depending on how big your garden is:

Small gardens

Narrow widths, such as our 6ft (1.83m) and 8ft (2.44m) polytunnels, suit small gardens and beginners getting started on their growing journey.

While compact, these small garden polytunnels are built to the highest standards using the same materials as our larger structures.

If space is limited, consider vertical growing options and staging to maximise yield. This may include crops like tomatoes and climbing French beans.

Medium gardens

For medium-sized gardens, our 10ft (3.05m) polytunnels are popular as they offer enough room for wide beds. They also allow you to move easily inside, with room for a central path with crops on either side.

Crop bars can be added to hang baskets, and you can dedicate some space for shelving or storing equipment.

A range of cover types and doors are available in this polytunnel size.

Large gardens

If you have plenty of room in your garden, consider a 12ft (3.66m) or 14ft (4.27m) wide polytunnel.

These sizes allow you to create a versatile space with multiple beds and a double-path system. You can grow in the ground or use staging and raised beds.

Thanks to the generous interior, you could even create dedicated zones for propagation, potting and trellising.

What's the best size for an allotment polytunnel?

The best size for an allotment polytunnel depends on the size of your plot. Our 8ft (2.44m) and 10ft (3.05m) wide polytunnels are very popular sizes with allotmenteers, however if space allows, it may be worth choosing a 12ft (3.66m) wide structure.

This will give you flexibility to grow a range of crops, while leaving enough space for watering systems and gardening tools. You'll also be able to create a central path or double-path system for easy access and movement.

Before choosing between our standard polytunnel sizes, measure the site and leave enough exterior space for building the structure and for future maintenance.

What size polytunnel do I need to start off in commercial growing?

If you’re growing for business, your polytunnel needs to support your workflow and the scale of your output.

Our commercial polytunnels start at 16ft (4.88m) in width, providing a sturdy growing environment for year-round use.

The largest in our commercial range is 30ft (9.15m) wide and is designed for large-scale growing. It allows plenty of space for multiple rows, irrigation systems and more.

To figure out what size polytunnel you need to start off commercial growing, ask yourself:

How will I move trays, tools and plants?

Wider widths or double door setups make this easier.

Where will I keep the equipment?

You might wish to dedicate one end of the tunnel to storage, potting or packing.

How many beds do I need for succession planting?

Continuous production requires clever layout planning.

What’s my projected weekly output?

This helps determine how much growing space you need.

How much does a commercial-sized polytunnel cost?

There's no quick answer to this question, as the cost of a commercial-sized polytunnel will depend on several factors, such as:

Size
Door configuration
Cover type
Foundations
Optional extras like irrigation and growing aids

All our polytunnels are expertly crafted from high-quality, durable materials, such as galvanised steel for the framework and pressure-treated timber for doors and base rails.

This means they offer exceptional value for money and a good return on investment as they're built to last.

If you’d like a quote or have questions about the cost of our polytunnels, don't hesitate to get in touch with us.

We can chat through your goals and site conditions to find a solution that suits your needs and budget.

How to measure your site

Before comparing standard polytunnel sizes, take a moment to measure the usable space you have. Make sure you:

Check access: Ensure you have enough space to bring compost bags, tools or wheelbarrows through doors and move around all four sides of the structure.
Allow space outside the frame: You’ll need access all the way around to secure and tension the cover and install anchor points.
Think about foundations: Ideally, your site should be reasonably level from side to side. However, a polytunnel can be installed on a slope; just make sure you adjust accordingly when driving in the foundation tubes.
Consider orientation: If possible, install your structure side on to the prevailing wind.

A quick sketch on paper can help you visualise pathways, beds and door locations before you choose a size.

For more details, take a look at our construction advice, which covers everything from site preparation to foundations, fixings and fastenings.

Alternatively, you can contact our Construction Advice Helpline 7 days a week until 9pm. Just give us a call on 01282 811250 if you need any help.

Why buy a polytunnel from Premier Polytunnels?

We're a family business with decades of experience designing and developing polytunnels.

This means you can purchase with peace of mind, knowing that our products are made using the very best materials that perform well for a long time.

We provide free UK delivery across mainland England, Wales and Scotland for orders over £100 and a 28-day no-quibble, money-back guarantee.

For more details, please take a look at our delivery and returns information.

Get expert advice on our UK polytunnel sizes today

Whether you're nurturing your first tomato plants for summer salads or launching a small growing business, choosing the right polytunnel is key.

From standard polytunnel sizes for gardens to large commercial structures, there’s an ideal option at Premier Polytunnels for every grower.

If you’re unsure which size is right for you, get in touch with our friendly team.

You can send us an email, call us on 01282 811250 or fill in our contact form for expert advice on choosing the right polytunnel.