We have used support posts and an overhang of corragated steel or plastic like a carport roof.

@Thomas Robb  Lets take them one by one.1)  Are you sure it is PVC and not white plastic pipe that is made for that purpose. 

Check to see if the tenant really had the glass windows frosted, or if he merely applied a removable frosted plastic film on them.

Laid black plastic down first to keep the weeds down and covered this with mulch.Despite there being a water spigot ATTACHED TO THE END OF THE RAISED BED the only water these poor things got from the tenants were rain that dripped off the roof. 

On some of the lower priced showers we have installed plastic laminate shower doors. 50% the price of glass, much lighter & after one shattered it was the safest option. 

Check all vents, A/C vents, heating vents with plastic sheets over and taped it.

You could put out some bright colored planters and some beautiful taller plants in those that will dress it up.I'd maybe do some interior lighting around the windows to give it a pop if that's what your looking for, I work in a old traditional building,, we did LED track lighting that's in the plastic tubing around the main floor windows and really pops when you drive by. 

Tar the cracks and put plastic over followed by another layer of tar.

The tenant has closed off the upstairs with plastic sheeting and moved her bed into the living room because she couldn't keep the upstairs heated.  

We hated to replace some of the flooring that was almost new, but they had used two different faux wood patterns/styles that clashed, and it looked somewhat cheap and plastic.