Use The Correct Material
Homes can be constructed from many different materials both natural and manufactured however, not all these materials are suitable as building materials and some can only be used in protected and or non load bearing sitiations.
One such instance is where materials better suited to internal use have been used for an external situation such that they are not able to withstand the environment they are exposed to and may be vulnerable to weathering, corrosion or fungal decay which would compromise their strength.
Another example is where a material has been used which does not have sufficient strength for the loads and stresses which it will have to endure. The type, quality or instalment of material is not suited to its application or context, where this may be prescribed by building codes or legislation.