<prompt> Human: Wife and I want to buy a house in about a year. Im trying to get my head around everything. Our current rent would afford us a 15 year mortgage on a 170k house with 20 down including taxes, but Im wary since a house carries extra possible expenditure repairs etc and we will likely start having kids in a few years. To me, the wiggle room of taking a 30 year mortgage and paying as much as we can afford towards it in boom and just the repayment amount in bust sounds like a good plan.What are the upsides and downsides to this approach?  <response>: The good thing about the 30 year loan over the 15 year is that it reduces your required payment. You have the flexibility of being able to pay it off sooner than required but not the obligation to do so. The cost for that flexibility is the difference in interest rates. If your car breaks down or you end up out of work for a little while it could make all the difference. Also, since the difference in rates is so low right now, you could also invest the difference in payments and make some extra dough on it when rates get back to historic norms. 