If you’re considering adding a garden room or outdoor building in Cornwall, one of the first questions you’ll likely ask is whether planning permission is required. The good news is that in many cases, the answer is no – but it does depend on the size, height, and intended use of the building.

Understanding the rules around permitted development, mobile homes, and lawful use is essential before progressing with your project. At Garden Buildings Cornwall, we help customers design and install bespoke structures that comply with current regulations while still achieving the perfect space for their needs.

Do I need planning permission for a garden room in Cornwall?

In most cases, garden rooms fall under what is known as permitted development rights. This means you can build without applying for full planning permission, provided certain conditions are met.

Typically, a garden building will qualify if:

• The total footprint is under around 30m²
  
• The structure is single-storey
  
• The maximum height is generally 2.5 metres
  
• If placed more than 2 metres from the boundary, the height may increase to:
  
  • Up to 3 metres for a flat or pent roof
    
  • Up to 4 metres for a pitched or apex roof
    
• It is used as an ancillary space (such as a home office, gym, studio, or hobby room)
  

These guidelines make it possible for many homeowners to create highly functional outdoor spaces without the delays and costs of a planning application.

However, the key factor is always use. As long as the building is not used as a separate living accommodation, it will usually remain within permitted development rules.

When a Garden Room Becomes a Home

The situation changes when a garden building is used for sleeping accommodation or self-contained living.

If the structure includes sleeping space, a bathroom, kitchen, and operates independently from the main house, it may be classed as a new dwelling. In these cases, planning permission is often required.

This is where many homeowners become interested in alternatives such as garden lodges or mobile homes, which can sometimes offer more flexibility under different regulations.

At Garden Buildings Cornwall, our bespoke timber frame mobile homes are built to comply with the 1968 Caravan Act and BS3632 Park Home Regulations. This distinction is important, as it can significantly influence whether planning permission is required.

Do I need planning permission for a mobile home in Cornwall?

In Cornwall, many garden buildings do not need full planning permission if they fall under permitted development rules. However, if you want certainty, you can apply for a Lawful Development Certificate (LDC) through Cornwall Council. This confirms your building is legal and helps avoid any future planning issues.

Despite the name, mobile homes and lodges that fall under 1968 Caravan Act do not need wheels, but they must be transportable and meet specific size limits (typically up to 20m x 6.8m).

To qualify under caravan rules, the building must:

• Be within the garden of the main house
  
• Be used as ancillary accommodation for family or guests
  
• Be built in a way that allows it to be transported in sections

• Not be a separate rental or independent dwelling
  
• Not change the use of the land
  

If these conditions are met, planning permission is often not required – but it is always best to confirm with Cornwall Council, or apply for an LDC for added reassurance.

Planning Advice and Peace of Mind

While many garden buildings fall under permitted development or caravan legislation, every site is slightly different. Factors such as location, land designation, and intended use can all influence whether permission is required.

That’s why we always recommend speaking with Cornwall Council early in the process. In many cases, applying for a Lawful Development Certificate is the simplest way to confirm everything is compliant before construction begins.

Ready to Plan Your Garden Room, Lodge or Mobile Home in Cornwall?

If you’re considering a garden room, lodge, or mobile home in Cornwall, the first step is understanding what you can build on your site and whether it falls under permitted development or requires planning permission.

At Garden Buildings Cornwall, we are a family-run business based at Goonhavern Garden Centre, specialising in bespoke timber frame garden buildings, lodges, and mobile homes.

From design to installation, we work with you to create a space that suits your lifestyle, budget, and long-term needs.

Get in touch with Garden Buildings Cornwall today to discuss your ideas, explore designs, and find out whether your project falls under permitted development or requires planning permission. 

We’ll help you make the process simple, clear, and stress-free – so you can focus on creating your perfect space.

Please note: Planning regulations are subject to change, and guidance should always be confirmed with Cornwall Council or a qualified planning advisor before proceeding.

At Garden Buildings Cornwall, we know that creating the perfect garden building isn’t just about putting up a structure – it’s about turning your ideas into reality, without the stress. From the very first concept to ground preparation, construction, and finishing touches, our experienced team can take care of every stage of your project, so you can simply sit back and enjoy the transformation.

We offer a complete, managed approach, handling everything from design and installation to all the finishing details. This means you don’t need to coordinate multiple trades or worry about scheduling – our team takes care of it all.

Living in Cornwall can bring its own challenges, especially when it comes to access for garden buildings. That’s why we provide a free site survey, allowing us to fully understand your space and plan the best solution. No project is too big or complicated for our skilled professionals, and we’re here to make the process as smooth as possible.

Groundworks and Foundations

A solid base is crucial for any garden building. At Garden Buildings Cornwall, we can advise on and provide all the groundwork your project requires, from demolition and removal to ground preparation and decking. Two of the most popular options for foundations are groundscrews and concrete bases.

Groundscrews are a cost-effective, environmentally friendly alternative to concrete. They provide robust support for your building while minimising disruption to your garden.

Alternatively, we can lay a concrete base that’s strong and durable, made with a special mix to prevent cracking, and carefully leveled so it’s perfectly flat and square. A precise base ensures the longevity and stability of your garden building, giving you peace of mind from the outset.

Beautiful Outdoor Finishes

To complement your new garden building, we offer a wide range of composite decking options. Our decking is designed to be long-lasting, low-maintenance, and slip-resistant, available in vibrant colours to suit any style. It’s the perfect way to create a stunning landscape around your garden building, enhancing both functionality and aesthetics.

We also offer a variety of exterior finishing solutions, including balustrades, glass verandas, and retaining walls. No matter your outdoor requirements, our talented team can create a seamless, polished look that ties your garden together seamlessly.

Expert Timber Protection

At Garden Buildings Cornwall, we don’t just focus on aesthetics – we prioritise longevity. We are proud to be an approved installer of Postsaver rot protection products, ensuring that all timber posts are protected from decay. This gives your garden building a solid foundation that will stand the test of time, regardless of Cornwall’s changing weather conditions.

Project Management Made Simple

We understand that modern life is busy, and coordinating multiple trades can be stressful. That’s why our team can project manage every aspect of your garden building, from base preparation to interior fittings. From the first fix to kitchen installation and final touches, we ensure that all components of your project are completed efficiently and to the highest standard.

Our integrated approach means you don’t have to worry about logistics or scheduling – we take care of everything so your dream garden room is ready to use as quickly as possible.

Visualising Your Dream

Planning your garden building should be exciting, not confusing. To help you see your vision come to life, we use 3D software and CAD drawings. This allows you to explore different layouts, designs, and finishes before construction even begins, ensuring your garden building meets your exact needs and expectations.

Local, Trusted, and Experienced

As a family-run business based in Goonhavern, we pride ourselves on our reputation for quality and reliability. We love to read the 5-star reviews from happy customers praising our professionalism and attention to detail. 

“They do the complete job from start to finish – they prepare the ground and erect the cabin so you don’t have to find other tradesmen to do any other work…First Class” ★ ★ ★ ★ ★ – Bernard Curnow 

Our commitment to excellence and customer satisfaction means you can buy with confidence, knowing your project is in safe hands.

Aftercare and Warranty

We don’t just complete your project and leave – you can rely on us for continued support. Garden Buildings Cornwall offers a warranty on both materials and workmanship, giving you reassurance and peace of mind long after your garden building is installed.

Your One-Stop-Shop for Garden Buildings in Cornwall

From the initial idea to the final installation, Garden Buildings Cornwall is your one-stop solution for garden buildings in Goonhavern and the surrounding areas, including Newquay, Truro, Padstow, and Perranporth. Whether you’re looking for decking, verandas, retaining walls, or a complete turnkey service, we have the expertise and experience to make it happen.

Visit our Goonhavern show site or contact us today to discuss your ideas. Tell us your vision, and we’ll guide you through the entire process, turning your garden into the perfect space for work, relaxation, or entertainment – no matter where in Cornwall you are.