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There might be hidden solutions in the new home. A friend of mine noticed that the front porch of his home was brick over cinder block like the rest of his home but down in the basement the wall ran straight with the wall the front door is in. So he drilled a test hole high in the basement wall and borrowed a borescope. Turns out there was a fully walled off room the size of his front porch behind the cinder block wall. Enter a concrete saw, a custom vault door and new floor to ceiling bookshelves in the room beside the front porch and one gets an instant custom vault. The basement room looks like its his downstairs office, but swing out the middle bookshelf, and there is the hidden in-wall vault door that opens into the space under the front porch. Six sides of either poured concrete or cinder block, now that is pretty secure when most of it also has dirt covering 3 sides.
Also with some houses with poured walls, there ends up being weird angles in the basement walls. The sheet rock guys usually just follow the poured walls. If the angle and offset is big enough, the new owner can make the wall completely straight and have a long thin hidden room.
My basement had a weird room in the middle of the basement. The house originally had two 80 gallon water heaters and 3 HVAC furnace/air handlers in there. When the water heaters needed replace, I went with two Outdoor Rinnai on demand water heaters, put in a multi-zone HVAC system, and put the In-Law HVAC system in the basement storage room. This made a huge space to hide my two safes in behind a false wall in what now looks like an equipment room for the main HVAC. I mounted an empty alarm system panel box I bought at a flea market on the false wall and ran 16 false leads out of the box and have the alarm transformer plugged into a dummy outlet in the false wall.
One can always get creative with basements. Its just takes some exploring and planning or a healthy dose of money to make an opportunity if one doesn't already exist.
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