"The trim around the windows looks skimpy and the mitered corners of the J-channels are uneven"

What trim was supposed to be around the windows? That is a typical Andersen window frame with J-channel. What were you expecting?

J-channel's were cut a little funky so the miter could definitely be better. But looking at it it appears he may have run the head and sill square and lapped the sides which is what is what is adding the funky appearance.

Every installer has their way of doing it unless you specifically ask him how he does the corners and what other options he could suggest i.e wider J-2 1/2", or 3 1/2" etc. or decorative trim, etc.

Does it match the other trim on the house?..that would be my first requirement...agree the miss on trim match on the bottom should be re-done...

If you are stuck with it... as is ...i would paint the trim to match the windows better...the lighter color just draws the eye to the issue...

I am just a homeowner, not an expert on windows, and didn't know to ask about trim when I hired my GC to install the two windows. But my other windows which were installed about 7 years ago by someone else are all fine and have 2-3" trim all around, then the J channel around that. I will use them for comparison when attempting to resolve this issue with my GC. I appreciate everyone's input. Many thanks!

Carol, that's a whole different story, he should have matched the trim like the rest of the windows... You have every right to ask why he used something else.

Good luck.

Any ..GC...should know better...but he may have a feasible excuse...so you can just explain what you want...this is a diplomatic problem more than something to over worry about...

It looks ok, he could perhaps cut the corners on the J. He is probably just a general contractor that does everything and doesn't focus solely on windows. Unless he stated a specific type of trim in the contract, what you received is quite common.

I've seen far worse J channel, if they are lapped properly simply clipping the overlap will clean that up. As far as trim surrounding the window, as explained above, you don't have any. You have the window frame against the new J channel which is probably the closest match that they could get. Should the contractor have added trim? Depends on how the job was sold and what was discussed. Certainly it would cost money. If it was written up with trim and he didn't provide it, he owes you some trim. If its a case where it wasn't in the scope or charged for but now in hindsight you would prefer it, I'm sure that he could provide you a quote to do so.