Did mine yesterday, everything was meticulously gone through including a Google maps location to your house (officer did it there and then) which they printed off, also if you have children they wanted copies of blue book for them also, which wasn't required last time
After the first extension, they tell you not to bother bringing your children in, just show their birth certificates and of course at least 6 photos of you and all the kids,wife in front of the property and inside the house