Pre-fab or bespoke?

A modular garden room comes in kit form, with basic elements of customisation available, while a bespoke option will be designed to fit your space and built on site.

With a modular outbuilding, you know what you're getting and for how much. Most firms that sell kits will offer add-ons, such as insulation, door and window options, for a somewhat tailored finish. You'll be limited in terms of size and shape, though.

Many modular buildings are sold for DIY installation, which saves on costs. However, it is a job for an experienced DIYER.

A bespoke design, whether your own or an architect's, will exactly meet your needs and the size and shape of your plot. It will also let you be bolder with materials and finishes. This is more of a job for a professional, which will affect the final cost.