Yes there is a way to incorporate both. If your longterm goal is for him to go outside then start by having him out as much as possible, especially after eating, drinking, sleeping and playing. This will create the opportunity for praise which is critical to success. If he cannot stay out a lot due to weather or your schedule the take him out as often as possible and stay until elimination occurs. The palace is used as a safe secure space while you are away or asleep and allows him an elimination area until he is old enough to postpone elimination until you can take him out.