At work, do people with positions like yours routinely wear chinos and collared shirts? Do either your superiors at work, or clients, seem to have any issues with such clothing? Do you have any discomfort with the idea of dressing that way? Do you think there'd be some value in dressing either more or less formally, and if so, are there likely to be any drawbacks to the decision?
I've been to places of business where "look nice, because clients will be around," has meant everything from "no really bad stains on your shorts or t-shirts," to "wear a grey or navy Brooks Bros. suit, and your dress shirt had better be solid white," and everything in between.
Oh, and to reiterate what mimo and I have already mentioned, if you're going to wear a tie, you ought to be wearing a sport coat or suit. The necktie-with-no-jacket look is seldom a good one. (When at the office, I strongly prefer wearing a suit, over wearing a sport coat, since the sport coat is not traditionally workplace appropriate. However, this may be irrelevant at your place of work. After all, neither are chinos traditionally workplace appropriate.) (Mind you, on social occasions, I have nothing against wearing a sport coat. It's sometimes a better choice than a suit.)