Short answer: The Bible doesn’t really say how long it took, but it was less than 120 years.
Bible Reference: Genesis 5:32, Genesis 6:4 and Genesis 7:6.
In Genesis 6, the Bible says that roughly 1600 years after the creation and Fall of Adam (if you count up the geneologies) that God saw that the world was filled with violence and wickedness to such that it repented Him that He’d ever made man in the first place! In Genesis 6:4, we read that God said, “My Spirit shall not always with man… yet his days shall be 120 years.” But Noah found grace in God’s sight, and it was to Noah that God gave the blueprint for the Ark.
But how long did it take to build the Ark?
Read the rest of this article at Noah’s Ark: Beyond Flannelgraph : How Long Did It Take Noah To Build the Ark?.
*Noah’s Ark: Beyond Flannelgraph is a ministry outreach of DefendingGenesis.org.