This is assuming you have the (house or community lot) in your library.
1. Select the build you want to place in your game.
2. Click the Place lot button on the lower right corner of the build.
3. Pick and click on the lot you want to place the lot on.
4. Click the Check mark to the lower right to confirm.
5. Place it furnished or unfurnished.
6. Click on the lot and select the Build button (to the lower right) to edit the build.
More information on how to place lots:
How to Place New Types of Lots from Packs
http://www.carls-sims-4-guide.com/help/place-lot.php
