Much of my consulting work revolves around either finding retreat properties for my clients, or helping them design or retrofit houses, once they’ve bought a property. I often have to play the “voice of reason” role, especially with houses that will be within line of sight from neighboring properties or from public roads.
It is important to have a house that blends in with the style of architecture of your neighborhood. Yes, a Monolithic Dome offers great ballistic protection, but if it is the only one in your county, then it will attract attention. My advice: If you want ballistic protection but your house will be in plain view, then either build with insulating concrete forms (ICFs), or build a traditional brick house. If you want to add ballistic protection to a “stick built” (aka “bullet transparent”) house, then add a decorative rock or brick facade, depending on the local style. Only someone who looks closely will notice that it is a thick facing.
If your house will be situated behind a screen of trees, then you will have a lot more leeway in design options. There, you might consider an underground house, for example. But even then, try not to build a house that screams “retreat bunker house.” For example, if you install ballistic shutters, then back them with wood or vinyl panels, to make them look either like storm shutters, or like purely decorative shutters when they are in their normally open position. And if you install a large array of photovoltaic panels, then site them with both solar exposure and privacy from public view in mind.
Don’t build a moat. Instead, construct “decorative” masonry planters to stop vehicles, or “stylish” stepped planters. Either of those will stop 99% of vehicles.
If you buy large fuel tanks, then opt for underground installation. Not only will they be low key, but that will also give them protection from wildfires.
If you buy a backup generator, do your best to keep it out of public view and dampen the noise.
If you have any unusual vehicles (such as a Unimog), then keep it garaged when it is not in use, and and keep your garage door shut.
Anyone with a gun vault bolted to their garage floor should not only keep their garage door shut as much as possible, but also take the extra step of camouflaging the vault. A cardboard refrigerator box is better than nothing, but you might get creative and make it look like an actual refrigerator. (You can get dead, oversized “Frankenfridges” free or at very low cost at dumps, if you ask nicely. Craigslist is also a good source.) Or make your vault look like a paint cabinet, by building a hinged unpainted plywood cabinet with double doors around the vault.
If you are a ham radio enthusiast, resist the urge to buy a giant Yagi or Moon Bounce antenna. Also, consider getting antenna masts that can be telescoped when not in use. Also remember that vertical yagis stick out, but horizontal ones blend in. (They just look like television antennas, to the casual observer.) So consider getting one that pivots for operation in both polarizations. Not only will it give you better OPSEC, but it will give you better versatility.
In conclusion, do your best to make your retreat house unremarkable or invisible. You want to look like “just another hobby farm.” Adding a few kitschy trappings out at the county road helps with the subterfuge.