Not to dismiss many of the components of a home, but my perspective is the foundation and secondly, the framing. Those tend to be the parts of the home that are going to be the most challenging (and costly) to alter.
One of the first items when going into a rehab of a home is looking at the roof first.
The roof is the single most important part of a home. It is not the foundation.
Ever seen homes in Africa? They must all have some type of roof system, no matter how simple it is.
Foundation can be as simple as compacted dirt. The reason why we even have poured concrete foundations is because its to support the bigger heavier roofing systems that we have. The foundation is there to prevent shifting of the house.
Ive went without hot water before. That was hell. Ive had a leak in a roof before. That was hell too. But Id rather have no hot water than no roof.
The roof the main important aspect to a home. If keeps the rain and snow and all from entering causing major damages. The exterior envelope such as siding, soffit, doors, windows, ect… are also just as important to keep your home well seal from weather and unwanted things to come in.
What is more important, your brain or your heart? Both the roof and the foundation play vital roles in a home. As a foundation repair company owner, I have seen first-hand how devastating effects of deteriorating foundations impact a house or residential property. The biggest issues are floods in the basement which lead to extensive property damage, debilitating structural integrity which may cause a house to cave in, as well as pesky vermin intrusion. However, I also see how a roof as well as all the other components contribute to making a home habitable.
Correct, the structure envelope is the most important.