I’m not talking about replacing doors or sealing off walls, both of which are reversible - I’m talking about the type of grieving that leaves your building, or a section of it, inoperable. Most of the time this is done by chopping down a set of stairs and sealing off that access with a ceiling. Ceilings are indestructible - the resident can’t do anything about it.
At the moment you can prevent this on the ground floor by using an inconsistency in building rules - you can place a ramp on a foundation with a pillar in the middle, but not stairs. They can chop down the ramp, but because of the centre pillar they can’t seal it off. This of course only works on the ground level/foundation.
What I propose is this:
Allow centre pillars to be placed on top of ceilings. It makes sense that you couldn’t place one without a pillar directly below it, but the current rule of not being able to put a ceiling on a centre pillar should stay.
Allow stairs to be built even when there’s a pillar in the centre. As far ad I can tell is wouldn’t block traffic.
Retain the rule of not being able to place a ceiling over a centre pillar (as I said in (1)). It allows the player (and raider) to prevent ceiling construction. When a raider does it to a presumably unfinished house, the resident is faced with the usual annoyance - they can build over or around it. This is the better trade off when the other is allowing raiders to place ceiling wherever they want.