Welcome to Sweet Home 3D.
If the box dragged upon an other object is at 0 elevation and is smaller than the other object, then its elevation will be changed automatically.
Before asking more questions, be sure if you can't find its answer by yourself in the help included in the program, the user's guide, the FAQ or in the forum. This should be the fatest way to get an answer.
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Emmanuel Puybaret, Sweet Home 3D creator
