Lindsay Lohan -- I'll Move If It Makes Sam Happy

Lindsay Lohan is telling friends she had "no idea" her new badass beach house was right next door to ex-girlfriend Sam Ronson ...but she's ready to move out in order to "keep the peace."

Sources close to Lindsay tell us ... Lohan was aware Sam lived somewhere in Venice, Ca -- but she didn't know how close her new pad was to Ronson's home until family members saw the DJ pull in to the garage next door on Monday. 

Now -- after Lindsay's father went through all the trouble of moving her in -- we're told Lohan is considering moving out of the place after learning Sam was "pissed" at the situation. 

We're told Lindsay doesn't want to break the lease -- which would cost her big bucks -- but she also doesn't want to "ruffle any feathers."