if they spent the money to run 12ga wire through the house to begin with, they would probably have put a 20A breaker on the panel to start with (lets face it.. the breaker isn't the expensive part..)
obviously home run lengths play into consideration..
I'm not an electrician.. but I RARELY have seen 12ga run in a house.. (only one time, and it was because the loading on the circuits was literally 100' away from the panel.. )
if your outlets are wired by pushing the wires into the back of the outlet.. it's 14ga..
IMO.. there are times when the results might be worth the risk... "possibly" burning down your house is definitely NOT one of those times..
obviously home run lengths play into consideration..
I'm not an electrician.. but I RARELY have seen 12ga run in a house.. (only one time, and it was because the loading on the circuits was literally 100' away from the panel.. )
if your outlets are wired by pushing the wires into the back of the outlet.. it's 14ga..
IMO.. there are times when the results might be worth the risk... "possibly" burning down your house is definitely NOT one of those times..