From 2BHK to 3BHK — under-construction quality tips?

Visited Ansal Aastha Mig Zone last weekend. I'm currently in a 2BHK, thinking of upgrading to a 3BHK. Site par ek cheez notice ki: under-construction projects mein plumbing aur wiring lines ki quality kaise check karein? Builders bas outer finish dikhate hain. I'm wondering if the internal fittings will last. Any tips for assessing this during a site visit, ya humko bas trust karna padega?