Suddenly need a floor plan for that merchant’s home the PCs have decided to burglarize? Need the layout of the wizard’s home they are planning to visit? A quick search online for floorplans is an excellent way to get a simple floor plan, fast.
Here is a link to houseplans.com. Scroll down while on the main page and there are a number of headings for types of floor plans. I like looking under Architectural Styles and then under something like Spanish Home Plans or Victorian Home Plans. One nice thing is along with the layout of the floorplans, similar to what we use for maps, there are often more pictures showing the exterior of the home; useful if the characters are casing the location. (Since these are modern plans, you will need to edit the modern rooms, such as the car garage, but that could be turned something like a storage room.)
Here is one such plan. Included is a picture of the house and the first and second floors.