How Can I add Dimensions in 3D view Revit Architecture?

You can add dimensions to windows and doors so forth in order to constrain them. Go into the 3d view and click on the window, you will see the dimension pop up. otherwise you can do it in the elevation view. Im pretty sure you can dimension the house for representation purposes. I hope that i am on the right page.

First workplane tool Surface Set the desired look And then with tool Dimensions Aligend you to size Set to be directed to different

first pick workplane like pic 1
then add dimention with tools in annotate palet, like pic2

From the Architecture tab, Work Plane panel, select the set tool to set your work plane. From the dialog box (If you haven't setup any reference planes, levels, or grids) select pick a plane and select the face you wish to dimension to and the dimension should show up.

Also, make sure that your dimensions are checked in the visibility graphics annotation categories tab.