I built a 16x32 inground myself. I used a contractor to excavate (the more precise the hole the less hand digging later!) I also used a contractor to do the vermiculite on the bottom and it is the best money I ever spent. Working with that stuff is trying to whistle with mouth full of peanut butter!

A few tips
- overdig slightly if you're doing a vinyl liner, it stretches for a worry free fit.
- know your local zoning codes backwards and forwards before you start
- make your deck larger than you think you'll want, its cheaper the first time
- use schedule 80 around your heater. some will tell you don't need it but it's a lot less aggrivation in the long run
- invest in extra (and wide mouth) skimmers
- bury some cheap wire with your lines so you can find them with a metal detector later
- label EVERYTHING!!! do not assume you will remember what's what
- when you plumb your returns plumb them on a 90 degree angle straight down to the footer. This will prevent settling from tearing your lines out.
- doing it yourself is very time consuming - plan on burning at least a month or two. I worked until midnight every night by flood light and every weekend. Plus a lot of days off in between.
- if you have specific questions please feel free to email me at romansone16@gmail.com.