Oak is so phenomenally expensive, it might be more appropriate to use a less expensive species and reserve to oak for veneer, furniture, flooring, etc. Resource management.
It is somewhat overkill to use in a timber frame. Selling your oak might even pay for a softwood frame, plus some.
And, as said above, it will cure, check and twist, so the final result is open joints and untrue lines. Other species will better reward careful fitting.
But I guess people just love to say they have an oak frame. The name traditionally conveys solidity and strength.
Pete
