In sizing a man's vest.... if pattern doesn't say

Ok. I’m making a vest for the first time coz my DH wants one coz it’s cold up here in the mountains. So. I have this nice pattern from Knitting Pattern central, simple vest with a cable in front.

But now that I’m half way done with the back I’m thinking, shouldn’t it be a bit wider at the top? I just measured him and his lower back is like
14" across (he’s slim still thank god) but at the top, chest, he’s 17". The pattern doesn’t say to increase at the top. But wouldn’t it be a good idea to increase a few stitches or work on bigger needles. It’s a really bulky vest with raw direct from the sheep farm wool.

I don’t want it to be too tight! :rollseyes: Whatchathink?
Oh, here’s the vest:

From the picture, it looks like the pattern is made to fit the chest and then be bigger at the waist, rather than fit to the shape of the body. Will the bottom part of the stockinette part fit across the top part of his back?

Hm, I didn’t think of studying the picture like you Ingrid. I will go hold it up to the top part of him today. Simple, but sometimes you just don’t think it through (well me).