I recommend to my clients to allow 5% of their total budget as a contingency for variations throughout the building of a new house and 8% if their project is a renovation.
I find the main drivers of building variations are:
(a) Incomplete or inconsistent plans and specifications.
(The more detailed and complete the documentation is prior to start building the less chance there will be variations during the build).
(b) Clients change their mind during the building process because they do not know what they want.
(The selection of materials, finishes and fittings should be made prior to starting building and once nominated, they should not be changed. For most clients this is very difficult and often unachievable, so it is important to have the help and guidance of an architect and or an interior designer).
From my experience, the most common building variations are:
- Concreting, excavation and ground works
- Cabinetry design, finishes and bench tops
- Kitchen appliances
- Bathrooms (i.e. pluming fittings and tiling)
- Light fittings (especially feature lights)
- Special interior finishes such as wallpaper or timber paneling
- Window coverings.
Also, remember to make sure you get a copy of the builder’s “Variation Policy” before you sign the building contract, so you have a clear understanding of the way that variations will be dealt with during the building project.