Depending on the terms of the agreement, you may be able to withdraw or 'cancel" the agreement as long as the agent agrees to release you. Before you do that though, if you have been satisfied with the agents representation of you up until the meeting with the builder, I would make sure that you have voiced your extreme dissatisfaction of how the meeting went and let your agent know how you felt and why. If the agent isn't aware that you weren't satisfied or felt his loyalties were misplaced during the meeting, your agent cannot correct his actions/behaviors. Sometimes pointing these things out (ie communication) goes along ways.... Good luck, I hope everything works out and you find your dream home!!