This is an awesome easy build for anyone who wants to add a quick upgrade to any entrance in their house!

Step 1: Gather Materials

to make this, you'll need

9 sandstone (or any other block of your choice)
4 sticky pistons
2 pressure plates
2 Redstone repeaters
2 Redstone torches
22 Redstone dust

Step 2: Door Frame and Pistons

First, place 5 sandstone blocks forming an arch as shown in the picture above. Then place 2 sticky pistons on top of each other facing to the left. Next, move back one space and place 2 more sticky pistons, but this time facing to the right. Now add 2 sandstone in front of them.

Step 3: Redstone, Pressure Plate, Redstone Torches, and Repeaters

Now add a sandstone block behind both of the lower pistons and place redstone dust on top of them. Then in the middle of your archway place a pressure plate. Now in front of your pressure plate, dig down two spaces and then three to the left and three to the right. On the left side you dug, you should now dig one more forward, and on the right side dig two more forward as shown above. On the blocks with redstone on them you should dig one block directly under and leave one block under that. Now place the redstone torches in the middle of those two blocks. Also, dig one block directly under the block with the pressure plate on it. Next, wire redstone from under the pressure plate to both blocks with the redstone torches on them, and on the right, place a redstone repeater on the second block going toward the torch.(the repeater should be set to three ticks, which means right click it three times) Both pistons should be powered now.

Step 4: The Backside

Now on the backside you should place your second pressure plate directly behind the first one. Then dig the same two block deep trench you dug earlier and place your redstone dust and repeater. (also set to three ticks)

Step 5: Finishing It Up

Now all that's left is to cover up your redstone wiring, test the system, and build something awesome around it! This is my instructable, so please feel free to leave comments on how I can improve in any way.