The Fortified Homestead is the ultimate in self-sufficiency and survivalism. It allows a great amount of protection when TSHTF. Even a major global calamity like TETOTWAWKI may be weathered with some comfort by a homestead well protected and defended.
These have all the qualities of a homestead and Survival Retreat but have defensive attributes that include:
Fences and Walls
Defensive Elements such as a blocked off road or valley
An underground shelter or bunker
Several weapons to arm the inhabitants and possibly friendly neighbors
The drawbacks can be they cost an exorbiant amount of money and may end up not being worth it if the money is better spent in other parts of your project. In some areas having large gates, fences and walls may break local covenants and restrictions placed by the local authorities.
In an incorportated county for example there are often codes and electrical requirements.
Finally, unless you are building it all yourself the construction workers employed to build the extra additions may lead to OPSEC breaches at a later date.
It can be no good having a nice private secure homestead if half the local town or city is going to show up in a disaster expecting to be let inside.
Also, if the area is visible from a highway or interstate having a large compound or buildings will attract many eyes, some of whom may not have your best interests at heart.