Sweet Home 3D is an interior-design app that lets you create 2D floor plans, add and arrange furniture, and then examine your work in 3D.
Available for free: Although the Mac App Store and Amazon offers a $13.99 paid version with 1,200 pieces of furniture, check out the free version, which comes with 100 furniture pieces.
Easy to get going: To start, click the New Home button in the toolbar. If you have a blueprint or drawing of your home design, you can import it to use as a background as you create your floorplan.
Add wall details: Use the Create Walls command to draw walls on your design. Alignment tools help you precisely add walls. Once a wall is added, you can reposition it and add doors and windows. Doors and windows automatically can orient and resize based on the orientation and thickness of the wall.
Draw rooms and add levels to your house: If you want to place rooms within walls you've created, click the "Create Rooms" button and then place the room. You can name rooms and modify the the color and texture of floors and ceilings. You can also add stories to your plan with the Add Level tool.
Furnish your place: You can also add furniture, which the app can automatically orient so its back faces a wall. You can change the size, height, elevation, and angle of a piece of furniture. You can also add 3D models of furniture, either created by Sweet Home 3D contributors or items you've designed yourself.
Check your work: A 3D view lets you explore your floor plans either with an overhead camera or as a walkthrough.
Some rough edges: You may need to do some fiddling to get precise room dimensions or exact dimensions of furniture or appliances.
Sweet Home 3D helps you design your home's new interior and furnish it. While its tools give you quite a bit of control over what you create, it may take a bit of work to get exactly what you are looking for.