I have done all of this, it still does not reflect light.
If you are trying to make the object reflect light (like glass armor or gems) the mesh has to be enabled to do so. If you open up the mesh in nifscope you want to first press f3 then select the object you would like to be reflective on the 3d shape, expand the nitristrips line that is in blue (by selecting the plus) select texturing property and on the bottom where you see apply_modulate under value you want to double click and select apply_highlight (do not select apply_highlight2) then go back to the list on the top left select the nitmaterialproperty for your shape and rename the value to Envmap2.
Rinse and repeat for every shape you woudl like to be reflective. I would also recommend lookign for some tutorials on basic mesh editing on nifscope as you can further adjust the appearance of the mesh by editing the nimaterials tab
The alpha map in your texture will determine how reflective each area is to light. The lighter it is in the alpha map the more reflective.
Note: I've never tried to do this on buildings but I assume it's possible.
Hope this helps.
M.S.