A good free tool is SketchUp , you can draw the house up, to exact scale and then pan around inside and out in 3D and have a good look .
The free version is now called Make , I think its the same as the pro , but just for personal use.
Get it here:
SketchUp | 3D for Everyone
Plenty of videos showing how to use it , only takes a few hours to get the basics.
Really advanced software , but easy to use.
Heres part 1 of 4 , for beginners.
Originally Posted by Koetjeka
Originally Posted by Buckaroo Banzai