They are very rare. You can sometimes find them when a developer has already started construction - but even then they are becoming more and more rare.
The Wyatt Condos just had a buy with 5% program.
Always be aware that you still need to come up with the balance at closing - if you are buying with 5% down it's even more important to speak to your bank about how much down payment you will need at closing so you aren't left scrambling for large amounts of cash when that time comes.