@dmyhill thanks 🙂  

OK I just wanted to thank you all for the replies - I haven't had much time to post in the last couple of weeks. I'm none the wiser about a better me...

@chris-mills Can you explain what you mean by never rely on a resection? What would you use instead?

I am taking the same measurements from the same position using the same control points and using the same instrument, that's why it's so frustrating w...

Thanks for the replies all. ?ÿ I'm monitoring generally residential houses so nothing as big as a dam. I wouldn't think that a brick house would be ...

It's retro targets so I'm sighting them, and doing two faces as I said before. Good idea to check the optical plummet, I will do so.