A.J.'s house is considered much bigger and nicer than Timmy's house. It is often protected from the outside by security systems that A.J. or his parents installed, one such invention is a laser that targets girl scouts, which A.J.'s parents reprogrammed to also target Chester. Next to the house is a set of train tracks, and across from that is the Happy Trails Trailer Park, where Chester lives.
A.J's house is actually a mansion. The outside of the house is colored white, with green colonial windows, front door, and possibly hard tile roof.
The first floor has the living room, dining room, and a washroom.
The second floor has A.J.'s room with his scientific lab and his parents' room. Timmy once showed Cindy Vortex from Retroville his "does-not-belong lab" because he pressed the cloaking button and A.J.'s dad once hit the walls and fell from the second floor. A.J. keeps his scientific lab hidden with a simple light switch, when he flips it, it causes the floor and wall panels to flip over, revealing his secret lab. Oftentimes, there is a tube filled with a green liquid with a clone of A.J. floating inside (dubbed as A.J. II). At one point, A.J.'s mother told him he needed to think of redecorating his room.
There is a stone patio in the back of the house, as well as a set of double doors with a light fixture nearby. There was also once a nearby tent with all the things for Timmy and A.J.'s sleepover. However, A.J.'s father forgot to block the animal violence on the Major Geek channel which in turn led to being A.J.'s sleepover not being great anymore (in Timmy and his godparents' opinion).
The front door has a number of traps that spring out whenever someone rings the doorbell. These traps were set up by both A.J. and his parents as a security measure. One of them scans the person at the door with a laser and smells them with a mechanical dog nose (as shown in "Mr. Right"). The other (shown in "The Big Scoop") points a giant laser at them and prepares to vaporize them (This was to get rid of any girl scouts offering something to A.J. and his family). The second type was installed by A.J.'s parents to keep Chester away from their house (though Chester claims that A.J.'s parents love him).