Stefan had to make sure the route to Elena's house was clear before he went to see her. Damon was at large with Klaus and that wasn't a good thing, they finally got him on a good track and then Klaus came to ruin it. As usual he always ruined something that was good.
After the area was secure and safe he ran quickly to Elena's house and knocked on her door. He prayed that she was home, he had been worried about her ever since this issue happened. "Elena!" he called out to her "It's Stefan please let me inside." he said knowing that Elena would hear him just fine.