A Garden Room vs an extension: Which is best?

If you’re desperate for more room in your home, then you’re facing the same dilemma as lots of people up and down the country: move house or add more space to your current property. If you’ve ruled out re-locating, you’ve probably narrowed your choices to two options: an extension or a garden room. Both offer extra space, but there can be a big difference in cost, planning requirements, construction time and the levels of disruption involved.

This guide will help you weigh up the options and decide whether a garden room or an extension is best for you.

Room use

Your first consideration should be how you plan to use the space. If you need to build a bigger kitchen or create an extra bedroom, then an extension is the obvious choice, as you’ll almost certainly want to integrate it with your main home.

If you want it to be separated from your house, then a garden room is the clear winner. Create your own garden gym, hobby room, garden office or relaxation space away from any distractions. But it doesn’t just have to be a place for privacy and seclusion; you can use it as a bar or entertainment area for friends, or as a cinema room for family film nights. One of the major benefits of a garden room is that you can customise it to suit your own exact needs - and if your needs change, your garden room can adapt.

A garden room can also transform your outside space into a functional part of your home, instead of being just a patch of grass or a place for storage. At Outside In, alongside our own landscapers, we work in collaboration with landscaping specialists to create a seamless connection between your garden room and the rest of your garden, making it a feature to enjoy year-round.

Cost

Cost is often the biggest consideration. A garden room is typically much more affordable than a home extension and is far less likely to throw up hidden costs. Garden rooms start from around £15,000, but prices can increase to £50,000 or more depending on the size and specification of the build. 

The average price of an extension in the UK according to Checkatrade for a small, medium and large extension is:

• Small extension (20m²) - £48,000
• Medium extension (30m²) - £72,000
• Large extension (50m²) - £92,500

You can of course expect to pay more or less than this, based on the type of extension you are building. The actual cost will depend on the type and size of room, specification, and the location in which you live (what a builder charges, cost of materials, etc.). For example, a conservatory is going to cost significantly less than a two-storey extension. 

So why do extensions cost more than garden rooms? Well, an extension will often require significantly more groundworks, downtake works, engineers, materials and labour and of course mess and disruption. You might also need to factor in additional expenses like architect fees and structural engineering reports. Garden rooms are simpler structures to construct and the build wont interrupt your daily life, but if you think they are just glorified sheds, you are very much mistaken. Modern garden rooms are designed for year-round use, with insulated walls and flooring, double or triple-glazed windows and doors and efficient heating systems. You can also customise them to suit your needs, like adding a sedum green roof, solar panels or smart lighting and heating controls.

Also, you don’t just have to settle for a single room. At Outside In, we have larger garden room structures, meaning you can have two separate spaces, or even add on a sheltered canopy, for a hot tub outdoor kitchen or barbecue area.

Time

Time is another factor to weigh up. If you suddenly need more space - perhaps you’re expecting a baby, having to care for a family member or you’ve taken up a new hobby - you’re probably operating on a short timescale.

The process for an extension often takes several months, from planning and approvals to construction and finishing touches. Unexpected delays can also occur, especially if planning problems or structural issues arise during the build.

The beauty of a garden room is that it can be built in a matter of weeks. Once you’ve given the go-ahead and confirmed your design, installation is quick and straightforward. And because they’re often prefabricated, the on-site work is minimal.

Planning permission

If you build an extension, there’s a good chance you are going to need planning permission - particularly if it will significantly alter your home’s footprint or appearance. The planning and likely building warrant application process can add several weeks, normally months to your project timeline. There’s also no guarantee that you’ll get planning approval.

Most garden rooms fall under permitted development regs, meaning you won’t need planning permission, as long as your structure meets certain conditions, such as height restrictions and distance from boundaries. We recommend you always check with your local council before going ahead with a build (something we are more than happy to assist with). If you're in a conservation area, you will require permission. 

Disruption

As well as taking a longer build time, extensions usually involve more disruption. Builders will need to access your home and will create noise, dust and mess. Depending on the scope of the work, they may restrict access to certain areas during construction, or you’ll have to vacate while work is going on. 

In contrast, garden rooms involve minimal disruption. Since the work happens entirely outside your main living space, you can carry on with daily life undisturbed. The shorter build time also minimises any inconvenience you may experience. 

If you value a stress-free experience, a garden room is the clear winner.

Adding value

Both options can add value to your property, but in different ways. By increasing your home’s square footage, extensions can significantly boost its value. This is especially true if the extension creates functional, high-demand spaces like an additional bedroom or a larger kitchen.

While a garden room might not add as much total value, you could see a better return in terms of value for money. Some garden rooms can add as much as 1.5 times the cost of the installation. They can also make your property more attractive to buyers when or if you sell your home, by offering a versatile, stylish space.

We might be biased, but we think if you add up all these considerations, a garden room comes out a clear winner. They are a quick and cost-effective way to add a versatile space with minimal hassle. 

If you’re planning your own garden room, check out our case studies for some inspiration or get in touch to see how we can help build your perfect garden room addition.