Modular Garden Rooms
Updated: 1 December 2025
Reading Time: 2 minutes 58 seconds
There are several routes to buying a garden room. You can choose a pre-designed building, a modular building that offers significant flexibility in terms of size, finish, and layout, or opt for a bespoke design where you have maximum control over the size, features, and finishes. This guide will focus on the modular route and demonstrate what a flexible option it is.
By constructing garden rooms in modules, much of the work is completed in factories, with the finished building transported to the site in manageable-sized panels. These modules lock together efficiently, allowing some designs to be installed in just a day, while larger, more complex designs can be completed within a couple of weeks.
What is a Modular Garden Room?
A modular garden room is a prefabricated, multi-layered, insulated structure that adds a versatile living space to your home. These rooms offer a quick and cost-effective alternative to traditional house extensions. They are standalone buildings, less than 2.5m high, which means they have maximum flexibility under Permitted Development rules.
Craftspeople build the floor, walls, and roof panels in factories using a combination of traditional carpentry methods and precision computer-guided machinery. The panels are designed to be easily manoeuvrable, even in spaces with limited access. Once on-site, the modular panels are assembled quickly, making the building weathertight in a short time and the project often completed in days.
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Customisation and Design Flexibility
When ordering a modular garden room, you can configure your room with a mix of solid wall panels, windows, fully glazed sections, and doors to suit your preferences. Many companies offer online configurators where you can design your ideal layout and see real-time pricing updates—no need to provide contact details at this stage, making it a great first step in exploring your options.
Here are a few companies worth exploring:
Notable Examples of Modular Garden Rooms
Some of the most established names in the industry specialise in modular designs, offering a range of styles that can be customised. For instance:
Modern Garden Rooms
Modern Garden Rooms specialises in contemporary designs, offering five unique styles that incorporate popular features. Their size options range from 2.5m x 2m to 10m x 5m.
Smart Modular Buildings
Smart Modular Buildings offers seven different ranges, from traditional to contemporary styles, with 64 different sizes to choose from using their configurator.
Warwick Buildings
Warwick Buildings offers a mix of contemporary styles and traditional pitched-roof designs, including a unique curved roof option.
Size and Space Considerations
Modular garden rooms come in various sizes. Be mindful that some companies quote internal dimensions, while others provide external measurements. Internal measurements help you understand the usable space, while external sizes depend on the thickness of the walls.
The smallest modular garden rooms typically start at 2.1m x 2.2m, with sizes increasing in 500mm or 600mm increments. Larger options can reach up to 10m x 5m. If you need a more specific size, a bespoke designer may be more suitable.
A Choice of Finishes
Modular garden rooms are built with durable materials that require minimal maintenance. Many modular designs come pre-configured with exterior cladding, such as Scandinavian Redwood, Thermowood or painted exterior grade MDF with options to upgrade.
Doors and windows are often made from uPVC, the same material used in house building, ensuring a long, maintenance-free lifespan. Roof coverings, typically an insulated steel system or an EPDM rubber membrane, are chosen for their durability and weather resistance. Pitched roof designs may feature Asphalt shingles or lightweight tiles, adding character to the structure.
Speed of Installation
One of the biggest advantages of modular garden rooms is the speed of installation. Once your design is confirmed, and a site survey is completed, the panels are manufactured, and an installation date is set. Depending on the size, a modular garden room can be installed in as little as one day, with larger designs completed in a couple of weeks.
Typically, you’ll pay a deposit of up to 50% upon placing your order, followed by a further payment just before installation, with the balance due after completion.
In-House Installation Teams
Most modular garden room companies use their own in-house installation teams, ensuring a quick and efficient on-site build phase. The teams are highly experienced with their specific construction systems, which further accelerates the process.
Bespoke Design Options
Some modular garden room companies also offer bespoke design services alongside their standard ranges. If you have specific design ideas or features in mind, it’s worth checking whether your chosen company can accommodate custom requests.
