Should offer Utility credit?

[David Swanson]

I have a single family home built in 1890, I insulated the attic and sealed around windows, new furnace and A/C but obviously my utility costs will be higher than new homes in the area. 

I have a well qualified applicant that is concerned about the utility costs and asked that I would lower the rent to compensate. I don't negotiate on rent price but it is a legitimate concern. So I thought maybe offer a credit during the Dec, Jan, Feb months to make them more comfortable with the utility costs. I did give them a history of utility costs and the average temp for those months.

How would I word a credit like that into the lease? Should I collect the full rent and then issue a credit? Am I crazy and should just say no way it is what it is? 4 bed 2 bath average in area is $1700 but those are newer homes, I am listed at $1450. 

Thanks, David