Hi Tim - It's very nice to have a dad on the boards. Welcome!
You seem to be answering your own questions very well. I think a lot of the time when you have a theory over what is affected dc sleep you are quite often on the right lines.
It may help you to know that for the first three months or so babies work on sleeping through the night. That is their brains are focused on sleeping for up to 12 hours straight. This is often at the expense of daytime sleep which can be a bit all over the place, hence some short, erratic naps. For the next 3 months (once they have sorted their nightime sleep) they focus on regulating daytime naps and lengthening them. Different parts of the brain control naps and nightime sleep apparently so this is partly why.
Although you've given us some great info, would you post your dd's daily routine please? The one thing that jumps out at me is that 10pm is a late bedtime. Going purely off this she could be overtired, but a detailed breakdown of her day will give us more idea.
Also can you describe your wind down routine for naps and bedtime if you have one?
While some babies are surprisingly adaptable it may be that the change to her routine and building work has disturbed her a little - especially is she is touchy/grumpy. So where is she currently taking her daytime naps and night time sleeps? And how quite is your house? (I'm guessing not very with a toddler charging about!)
And finally do you have either of the baby whisperer books?