A full-fledged private library. At least two stories tall, with floor-to-ceiling bookshelves, and a big suite of windows. A fireplace, too.
Behind a hidden door (built out of a bookshelf), the private office from this book, with the cylindrical bookshelf-area built in a hollow in the ceiling, and only accessible via a ladder. This, my private study, would have no windows.
Extra-wide doors and hallways, large enough for at least 2 people to walk side by side, comfortably. Stairways, too. (If you’ve ever had to move large appliances, you’d know how handy this’d be.)
Concealed, but easily opened access panels in the walls, over all power, telephone, and water lines. With lots of room for expansion, should these ever need to be upgraded, or some unforeseen lines have to be installed in the future.
Blast shutters and gunports.
The floors of the bathrooms and kitchen would be slightly sloped towards the center, where a drain would be.
A half-bath for every person living there, plus 2.
A big, wall-sized, museum style display case, filled with historical weaponry.
Suits of Armor, and at least one (working) grandfather clock.
The dining room would have a full-sized print of Guernica dominating one wall.
A fence. A really tall, sturdy, fence, surrounding all my property. Actually, I should probably make that a full-fledged wall.
Arts and crafts room, with HUGE worktables, and ample storage space. And a TV.
There would be a built-in TV cabnet in the living room…but the whole thing would be hinged to swing out from the wall, allowing easy access to the cables and ports on the back of the TV equipment.
TV would be carefully positioned so there’d be no glare from the windows.
Human bone chandelier. (They can be fake bones. I’m not picky.)
Fake dungeon room in the basement, complete with skeletons chained to the walls.
Air conditioning. And little (?) airliner-style air vents in all the rooms.