Sounds interesting, but what does it mean? Well, from the date of legal completion, that is the date you become legal owners of your new home, your housebuilder remains responsible for legitimate build defects. And this is known as the Builder's Rectification Period (previously also called the Builder's Liability Period).
If something appears defective within your property you should report it to your housebuilder/developer, to get it rectified. First, check to see if the problem is your housebuilder's responsibility, or yours (see our story on the Warranty Checklist and how to use it).
Assuming that you have checked and that you're satisfied it is a legitimate build defect, and that you are still within your 2 years window, then report it - using the App 'Managing Your New Home'.
Hopefully you will have found this short article helpful.