any time during the game, house or neighbourhood
open cheat box (hold ctrl+shift+c) the type
boolProp testingCheatsEnabled true
(exactly like that with capitals and spaces). To hold shift and click a sim or object - many new menus will come up.
!!WARNING!!:1) Do not click Force Error, if you do ALWAYS click reset
2) Can disable save, quit and neighbourhood buttons, use with caution!