Behind the scenes
City planSean had one rule when building... "structures must be taller than they are wide". This was intentionally vague, because it allowed for some fun. It let him get away with making a short building with a tiny base, and forced him to make buildings that have huge bases very tall.
Each building was isolated on its own baseplate, so they could be moved, rearranged, remodeled, shown, or photographed, which was pretty darn convienient. Most buildings were 16x16, 32x32, 48x48, 16x32, or 16x48.
Adding sidewalks adds to the realism of an urbanized city. Sean built them 8-studs wide, on the road plates. That way he didn't have a patchwork ground of green, grey, tan, and blue, due to the varied colors of LEGO base plates, and everything flowed nicely. By adding raised sidewalks to buildings that are recessed from the road, they blend in seamlessly. Sidewalks are 2/3 of a brick high (and every now and then there will be a sewer opening).
UndergroundSean raised the city up about 6 inches on 2x2-stud pillars. The animation to the right shows how he did it... adding the pillars, putting the baseplates down, and finally adding back all the buildings.
Then Sean added a subway system, basements, sunken plazas, lakes, and all sorts of goodies. Take a look at this sketch. This was a drawing he did early in 1998 when he first came up with the idea. You can also see the 4-lane roadways he was planning too.
Building heightIn residential buildings, Sean usually made each floor 6 or 7 bricks high, as Lego usually does in their models. This works well for the scale of the figures, as well as being proportional to the doors and windows. For commercial buildings, however, he made the lower floors about 12 bricks high, because real-life commercial cielings are twice the height of residential buildings. Here is an example.
The upper floors are smaller, to allow for more floors.
Sean did vary things, just so all the buildings wont have parallel floors. Most floors were usually taller, just becuase it's easier to reach into them that way.
Adding floors to buildingsSean invented his own means of putting cielings and floors into the larger buildings. Rather than use regular plates linked together across the building, he bought baseplates and cut them with an exacto knife to fit the shape of each floor. He did this for 4 reasons:
Real electric lightsOnce Sean had raised the city, he began adding little lightbulbs all over the place -- in streetlights, buildings, etc. He made a few designs showing how to decorate the light bulbs with LEGO elements.
About 5 of Sean's buildings had lighting in them. All the buildings were connected to a central underground power station, by running wires under the srteets. This allowed Sean to flip one switch to turn on the whole city!
IdeasHere's a list of improvments or creations Sean wanted to make to the city, but just never seemed to get around to.
InspirationSean gets inspiration looking at real life. The entire city was inspired by Manhattan, the most densly populated section of New York City. (Hence the name of the city, "The Brick Apple". -- For those of you unfamilliar with New York, "The Brick Apple" is named after "The Big Apple", which is New York City's unofficial nickname.)
So what about Manhattan can be seen in the city? The straight, gridded streets of midtown. Tall buildings that butt directly up against each other. One-way streets. The classic NYC-style subway entrances. Hot dog vendors! Lots of taxicabs. Sean even begun adding popular NYC landmarks, such as the Empire State Building and World Trade Center. He eventually wanted to add the Citicorp building and Grand Central Station. Maybe even the Brooklyn Bridge.
Where Sean built the citySean had an 11-foot by 15-foot area in the basement of his New Jersey home, reserved for building. (Here is a a photo of the room .) In the photo you can see all of his sorting bins out on the floor... They're usually stowed away, but he was reorganizing them the day he took the picture.
Sean had purchased lots of bulk-buckets, so he stored them all atop a pipe that ran along the wall about 3 feet up. The buckets pretty much reach the cieling.
Underneath the pipe he stored all my sorting-bins. He kept all the "regular" square bricks in big bins, and all the little special pieces in divided-drawer units ... the kind you get at hardware stores for sorting nuts & bolts.
On the floor next to the city, Sean had a large flat piece of smooth plywood that he used as a 'construction area' ... it's a lot easier to build on a hard surface. (That's all you need... to be working on the 7th floor of a building when all of a sudden the 1st floor buckles under!)