I know that there are ways to get around some of the issues and connect two rooms/structures that have different heights, but it doesn't always work & it would be nice to have some tool or setting built-in to allow us to attach a garage or ground level structure to one on foundation without it trying to add foundation or mess with the roof or refuse to do it. I'm not sure exactly how it would be executed, but even if it requires a cheat code, it would be nice to not have to jump through hoops to get it done & still have mixed results.

It would also be nice to be able to have basements that extend slightly above the ground level or merge the foundation walls with the basement by removing the basement's ceiling & allowing window placement. Another feature that would help for structures that are raised up would be to have ramps (and allow users to adjust width, length, and slope like roofs). So if someone wants to have an attached garage but still have it at the same level a the rest of the house, they could have ramps.

There could be window wells that can be placed against the basement wall which dig out the space around where a window can go (can be of adjustable depth, width, and pattern). It would be really cool to be able to manipulate the terrain to have it flush against a sunken wall for homes on a hill. Digressing a bit, but one of my childhood homes was built on a hill. From the front it appeared to be a normal 2 story house with garage, but the hill sloped down along the side and down behind the house for a full story so from the back you could see all 3 stories and there was a sliding glass door at the back of the basement. Subsequent owners expanded the deck, added a gazebo, and leveled out one of the sides to have another driveway & garage (it was a corner lot). I was able to find street view pics from google maps (which I will post further down the thread).

It would also be nice if there were crawlspaces inside the foundation/under porch areas where pets could hang out with little pet doors, louvered vents, windows, etc. I did figure out how to have stairs going down to a roofless basement portion to have exterior stairs in a walled in area, but it would be nice to have more options for basement entry points including ladders, spiral stairs, angled cellar doors/hatches, etc.

Since at least one of my homes had L-shaped stairs, I would love to have landings or the ability to place stairs & floor tiles on top of half-walls & have columns the same height as half-walls. I know that people can use foundations for stairs, but it sometimes creates issues & it would be nice if it was included as a feature & not something we had to do workarounds to get. Plus, it would be nice to be able to use the space under the stairs to have bookcases, small closets, a tiny Harry Potter bedroom, half bath, etc.

Another feature that would be nice for stairs is the ability to have asymmetrical rails (apply rail to one side only & mix styles). In particular, I'd like the ability to have wall-mounted stair rails. They can be designed to match rails that mount to the steps & be placed independently.

Since I'm mentioning stairs, why not have steps/stairs for pools as well as ladders?

TL: DR?
*Attached garages/split level as a feature w/o having to jump through hoops
*Basements that aren't just complete underground dark pits
*Basement windows/window wells/foundation windows
*Ramps for porches / foundation / split levels / hills
*Cellar doors/hatches
*Ladders & spiral/curved stairs
*Foundation/crawlspace vents & crawlspaces for pets
*Landings for modular stairs / half-height columns, load-bearing half-walls
*Asymmetrical rails & wall-mount stair rails
*Pool stairs/steps

Split level house from the front:


From the side



Back (as much as it can go) Out of view is on main floor there was a sliding glass door leading out to the porch and there was a sliding glass door to the basement.

View larger


Window wells & basement/foundation windows:








Foundation/Crawlspace vents






Ramps





Wall-mounted stair rails/bannisters