I've add this thread because I think it deserve this.
Reasons:
1. This is THE FIRST PLUGIN made for SH3D on 24.04 2009 by Michel MBEM
2. It is writhed very clearly and for me it is a very good example!
****** THANK YOU MICHEL !!!!******
Some historical events.
Michel first description on 24.04 2009 at version 1.0:

Rotates the whole plan (including walls, rooms, furniture, labels and dimension lines) clockwise or counterclockwise.

Michel last description on 24.05 2009 at version 1.2:

Finally, I've uploaded a new version of the plugin.
This one rotates the background image as well as the rest of the plan.
However, there's still a small problem that you will need to fix manually:
after the rotation process is complete, you will observe that the plan and the background image are not superposed no more.
So you can fix this by selecting the whole plan and dragging it so that it matches the background image again.
I've tried to fix this programmatically but with no success.
I will continue to try a better solution.
All your suggestions are welcome.

Considering as true the Michel statement:

This plugin is released under the GNU GPL license; so you have the right to alter it following your needs and to redistribute it within your own package.

I've update it a little.
As usually for me you could find the RotateHome-1.3.sh3p at Media Fire and at Source Forge.
What's new?
- rotate polylines
- support for multiple levels
- try to find a solution to correct positions of rotated items over the background.
- ToDo to rotate the labels (I forgot them [:(] )
Recommendation: uninstall all previously versions.

@Daniels118 You could also update the Plugin Manager to point at this version.

I invite all forum users to post in this tread the comments related to this plugin.