This stage is crucial, as if its not done properly you could be spending money down the line to fix things that could have been rectified by the developer.
I have included the basics here (the list could be bigger, but I have included the essentials) so you have a cursory understanding of what should be checked, although professional help is advisable if you are unsure or this is totally alien to you.
- Check services, fixtures and the building internally and externally.
- Check electricity supply
- Water, turn on the taps, flush toilets
- Check your white goods (cookers, fridges etc).
- Ensure sockets and switches are straight and flush with the wall
- Study your paint work.
- Make sure your floors are level
- Check floor tiles/for scratching
- Look for possible leaks and damp patches
- Check mirrors for scratches
- Any cracks in plasterwork
- Always check in daylight hours, preferably on a sunny day, as that really shows up poor workmanship.
After you have checked all your rooms, draw up a list of incomplete work or things that you are not happy with, then ensure the builder gets the list (probably through your lawyer) also make sure there is an agreed timescale for the work.
Never ever feel pressured to sign off until you are 100% happy that your requests have been met.