1.get wooden planks.

2.Build another house that looks the exact same as yours

or
1.Get worldedit
2.Do what the other people are saying how to use it.

Another option is using MCEdit. It's very user friendly. You just open up your level.dat file using MCEdit and it will give you a view of your world. From there you can simply select your house and use the features to move it wherever you want it to be. You can use this tool to flatten land, create oceans and many other things. World edit is also an option which has been said before. I'm not aware of its functionality in single player as I have never used it.

Can I use world edit in single player? Or do I have to be in a server? And thank you @KittyKarnage and @mdaddy14100

you can't do it without server commands, world edit, or modding. how ever you can just memorize the design of the house and rebuild it.

world edit! it is inside single player commands

btw wow kitty you are in like every post on the forums :3

heres link http://www.planetminecraft.com/mod/magic-box give this guy a plus one! this mod is awesome "SPONSOR!" if you get who i am quoting you are awesome

theres a mod called magic box that does just that!

world edit!!! (look up single player commands with world edit)

use the

//wand

//copy (or cut)

then

//paste (in the location you want it to be in)

World Edit.


EDIT: Ninja'd by KittyKarnage ):

World Edit:)