[Porsche-O-Phile]

+1 this is a good thing. Effectively they're asking you, "you are our client and technically the general contractor on the job hiring us as a sub to you - as such you are responsible for the necessary permits - however in the interest of making sure it gets done properly, we'll get them for you if you want".

This shows good faith, above board practices and (realistically) that they know they're dealing with an unsophisticated (in construction) "general contractor". Most guys you hire (technically subs to you acting as the "general contractor") wash their hands of the whole scene by simply saying "we're a subcontractor - the g.c. is responsible for all the permits, inspections, etc." In other words they hand you a bill of goods and if you don't either hire a competent g.c. or are one versed in construction, you could be getting non-code-compliant crap and never know it.

Take them up on it. I'd even pay them a little above actual cost to cover their time in going down to the building department, etc. They're doing the right thing and should be compensated for it, IMHO.