My kids love building things. They also love destroying their buildings. However, they don't love it when their siblings destroy their buildings. The older ones are respectful of each others creations, but with Alexander around...nothing is safe in our house. I am not very sympathetic when it comes to Alexander destroying their things. I just tell them that is what happens when you have a baby in the house and if they don't want him to ruin it, they will have to be smart and figure out a way to keep their building safe. Sometimes they haul the building materials into their room and close the door, but more often they just try to keep him occupied with his own building and if he is quick and gets to theirs, they just build it over again.
Nicholas was particularly proud of this building and requested some pictures before Alexander woke up from his nap :)