How to connect a rooftop with ground

sims-3

I would like to build a garage which is under the ground. Like this:

Garage under the ground

However, I am not able to connect the ground (on the right) with the rooftop of the garage (left). Is this possible and if so, how can I do it?

Ideally, I would like to paint the rooftop of the garage with grass, but I would not mind using floor tile for this.

I can't even get the ground next to the garage to the same height of the garage:

Not same height

I tried to achieve this goal using a cellar, but then I am not able to place the garage door on it's wall.

Best Answer

If memory serves, this is a limitation of the game in that even if you raise the ground to the roof of the "below ground" section of the house. that below ground section is still the first floor, on top of it is the second floor, and the raised section of ground is the first floor again. The two can not meet by means other than a set of stairs.

However, one thing you should be able to do is lower the raised ground slightly and put a foundation wall on top of it. Everything on top of the foundation is also considered the second floor, and if the top of the foundation and your 'underground' garage are at the same height, you should be able to connect them.