For minor work (i.e. quick exterior repair), I probably wouldn't bother notifying them. 

Water needs to be metered to tenants.Both units need repairs and remodel. 

Now before everyone jumps on me about, "If you sold under contract why are YOU making repairs?".

What are the needed repairs for this Duplex ?

Things are signed and put in writing *before* the actionable event happens.I highly recommend you research here on BP's forums and podcasts about how to find quality tenants.

What percent is standard that you use towards "emergency repairs etc" after the tenants pay rent and after mortgage.

I would say that your going to want at least $10,000 in reserve in case you have to make a major repair, have to pay the mortgage if not all the rooms get rented, and expenses you didn't account for. 

He has always done a great job for our family - he dependable, reasonably priced and does quality workhttp://protouchpainting.usAs a backup, my property manager uses the guys below.

New roof and windows needed along with some minor foundation repairs.

In other words you receive a 30% tax credit on the solar system as well as a 30% tax credit at the least on the roof that is under the solar system (full roof 30% depends on the advice of your CPA).Couple that with the roof now becoming a producing asset and offsetting the utility bill instead of a liability and the increase in appraised home value assuming the solar system is not leased then going solar makes a lot of sense at the same time as replacing/repairing a roof.