Please read all of this before doing it :) First go to creative mode then name your world for example: my world the build any thing then create a survival mode then name it for example again: my world 2 then quit to the mine craft PE then go to the file manager the go to the games folder then yoll see com.mojang... folder, then select the my world folder then copy the chunks.dat then go to the my world 2 folder then delete the chunk of the my world 2 folder then paste on the my world 2 folder the chunks.dat form the my world folder. Then exit to the file manager then start again your mine craft PE then select my world 2 folder then the house you build in creative will be on the survival but some times you need to find youre home make sure the the rage of the clear ness on your game will be on high level o you can see your house quickly :) Note:this will only work if your mine craft supports survival and creative and for android only.