Perhaps a bit more self discipline on my part would help here, but my usual playstyle is to keep the rooms as small as possible, trying not to waste a single tile of floor space. Of course, as soon as my Sims acquire an extra item of furniture, I have to rejig the walls to make it fit, possibly with knock on effects for the whole house since i left so little space.

But. no need to worry because you get a full refund on a wall when demolishing it so it's effectively free and instantaneous.

In real life the vast majority of houses are bought pre-built and few people (in the UK anyway) make structural changes. When they do, it's something trivial - a conservatory gets added, or a small utility room off the back of the kitchen on the ground floor. Perhaps someone puts an extra room in the attic space. A pennywise landlord might put a partitioning wall in to make two smaller bedrooms out of a single large one. The next owners may knock that down again.

However, almost no-one touches load bearing walls or builds extra storeys. In fact the majority of UK homeowners probably don't modify their house at all. When they outgrow it, they sell up and move in elsewhere.

Is there a mod that adds a little more realism to wall chopping ? I suppose i could use the cheat console to subtract the money i gained back after deleting a wall (in practice, such an action costs money because you have to pay someone to do it !) .

I guess part of the problem is that even the smallest plots in the sims are big enough to fit an 8 person house on with all the endgame extras, with a little care.