Peco offers a free "Free Energy Checkup" where someone inspects your home and gives you an "personalized report with recommendations for improving your home's energy efficiency"
Make sure the contract has all of the scope of work before signing.
If it is a solar project, make sure the interconnection agreement with Peco is approved before the installer starts the work (so you get the "net metering" credits when you overproduce electricity)
Never pay an invoice in full when work is still pending.
If it is a large project, engage 3d designers on fiverr (e.g. "bathroom design") to make a 3d render of your designed project. This will cost only $100-$400.
In Willistown, door to door soliciting without a township provided license is illegal. Call 911 for the police to come out. Tell them the direction of the solictor and physical description. See "Chapter 97 Peddling and Soliciting" details and exemptions.