In Iron Man 3, when the Mark 42 (a prototype) takes an unconscious Tony Stark to Tennessee. There he tries to repair the suit, but fails. And must take a car back to California, Miami and make some gadgets on his own. He is caught and summons a recharged Mark 42 to the location. He also saves several people from Air Force One in the same suit. Later when he goes to confront the Mandarin at the dockyard, he calls on his suits after he (and Rhodes) are outnumbered by the Extremis solders. Why doesn't he call on his suits earlier right when the Mark 42 was damaged or at other times when he needed them the most?
The key part is "wreckage of his house".
All the suits were in the vault, which were underneath his house. After Mandarin's attack, the vault was buried in rubble. After the attack, the rubble from the attack was cleaned up. By the end of the film, that had progressed far enough that the vault's doors were accessible again (we get a glimpse of this once Tony authorizes House Party, as it shows the workers clearing rubble as the vault doors open).
Answer taken from Sci-fi - Why didn't Tony Stark initiate the House Party Protocol earlier? by @Keen as suggested by Doorknob.