I'm thinking grants for making the outside of the property look nice, particularly near the Open Window Project area.

It was undeniable that the leasing company did not have the home inspected or professionally cleaned, fire alarms broken and missing, light bulbs burnt out, carpets filthy, windows inside/out so dirty you cannot see out of them, 1/2 inch of dust and dirt on the ceiling fans, window sills, bathrooms not cleaned...just a complete mess.

Using the numbers below, I would regain approximately half of my downpayment in addition to financing needed repairs (windows and vinyl siding) for the property.

In the room with the window closed and with the window open (as you might do on a warm summer night). 

Replace 8 doors, install weatherstripping in the entry door, repair windows hardware and window trim6.

Also keep in mind egress windows can cost 5k though that also adds value through lighting up the space. 

My business was an aluminium and PVC windows and doors factory so I´m related with the project management role.

Found a vacant duplex having broken windows and tall grass violation notice posted on the front door.

Is it worth investing in fibrex (Andersen) or fiberglass windows vs Vinyl windows from Home depot or Lowe's ?

If you are outside that window, then your financing contingency might not protect you.