Original version:

Here's a house.  Here's a door.  Windows: 1,2,3,4.
Ready to knock.  Turn the lock.  It's Play School!

The remix version of later years:

A house.  With a door.  Windows: 1,2,3,4.
Ready to play?  What's the day?
It's ...(whatever day it was)

AUSTRALIAN THEME:

There's a bear in there, and a chair as well,
There are people with games, and stories to tell,
Open wide, come inside,
It's Play School!