In Genesis 6 we read that Noah had detailed instructions as to how he was to build the ark. In verse 22 we read that Noah did all that God commanded him. Noah couldn't get creative with the ark, there were very specific things that had to be done in order that the ark would do what it was supposed to do. Noah was obedient to the word of God as judgment was coming near. We are to be building an ark, something that holds all the foundations of civilization, so that when judgment comes, we will be able to rebuild. If judgment doesn't come in our lifetime, then we would build for the next generations.