Is Converting a Shed to a Home a Cost-Effective Option?

Selling both kit homes and sheds, we receive a lot of enquiry about converting a shed to a home. A shed can be converted into a home. However, from experience, converting a shed to a home does not save any money over building a conventional stud-frame home.

In Qld, a shed is classified as a Class 10a building. The engineering is very basic and the approvals process is very simple. A home or granny flat is a Class 1. It requires a detailed set of plans, and engineering for the structure and slab. There are also site tests and reports that are required. On top of this, there are energy assessment requirements that must be met in regard to glazing, insulation etc.

That's the design element. Then there's the structural costs...

Everyone has heard builders mention 'structural beams' or 'structural columns'. When beams and columns become part of the design, the costs start sky-rocketing. In shed construction, these beams and columns are the main structure of the building. Known as 'portal frames', they are used in shed construction to obtain large open spans. They suit steel cladding as steel cladding can be fixed at further spacings that other types of cladding. On a large open area, light-weight cold-formed steel portal frames are the most cost-effective option. However, if using weatherboards, plasterboard, insulation batts etc, the walls need to be battened out, which adds to the cost. With a stud frame, some internal walls (load-bearing) walls, take the need for the large spans out of the design, making the build more cost-effective.

Portal frames are also very limited in design flexibility. Even adding eaves results in untidy looking joins which required expensive flashing to cover.

In short, building a home by converting a shed generally will not save any money, and can easily cost more. In the ever-going pursuit to build the most cost-effective kit home design, I continue to find that using a shed/portal frame design is not an option.

Many councils do allow a bathroom in a shed, and you can line a shed with ply. So you can have a 'studio' or 'workshop' that is a Class 10a (or equivalent). However, when lining the internal area, the costs start to outweigh a stud frame structure.