Eddie Murphy came up with the idea for The PJs 3 years ago after watching a show that had marionette's as the cast. He felt that today's prime time shows were unrealistic and he wanted a show that used unrealistic looking characters with realistic personalities in a realistic world. Out of this came tenants of an apartment building in the hood. The characters don't look normal with their large heads and hands but they deal with real world issues. Claymation wasn't used to make this series but Foamation was. Foamation is basically an evolved version of claymation because it acts the same but has some benefits over clay.
Since the characters were unproportional disproportioned sets had to be built. 
The sinks were built extra large because the characters hands and head were extra large. While the toilets had to be a bit smaller so that it was to scale with the bodies. This made the set strange looking without the actors but when they were placed in it all made sense. To produce multiples of certain props molds were used. Pattern making was also useful in the creation of textures used on objects such as building's bricks. A craftsmen would create a 2'x2' sheet of brick texture and glue it onto a piece of perforated metal. The sheet of styrene is then heated up and sucked onto the pattern by a vacuum, this process is called vacuforming.
Special effects like smoke and water spraying(common things in an apartment building) could not be produced effectively using clay or foam. So they had to be created using the computer. Other effects like pouring water and sweat can be produced using glycerin or epoxies.