While zombies will beat on your door in any version of Minecraft, they can only break one down in hardcore mode (or if mods are involved.) Zombies cannot break down an iron door, so you can use that. You can also be creative and use a series of sticky pistons to move blocks as your door. Zombies don't bother normal blocks, so as long as you remember to close the 'door' this works well and seeing the door open can be awesome.
Another trick, if it hasn't been fixed yet, is to use the trapdoor glitch. Create a two deep and at least one wide pit around your house. Use a trapdoor 'bridge' to get to your door. When night falls, open the trap door. Zombies pathing sees an open trapdoor as closed, so they try to walk over it and fall into the hole.
Also make sure the interior of your house is lit will enough that zombies won't simply spawn inside.