For years you've been hit with unsolicited mail and spam, warning you that the window of cheap financing is closing. Maybe you bought in at first, but after refinancing your home twice or thrice, your skin has become thick to the pitch.

Maybe you're not even aware that the past month has seen a brutal spike in borrowing costs, with mortgage rates having climbed higher each of the past four weeks. According to Bankrate, the average 30-year fixed-rate home loan shot up from 5.41% to 5.97% in that time.

What's a homeowner -- or a prospective homeowner -- to do? First of all, don't panic. Our Home Center packs an awful lot of sage advice and you should take your time to take it all in. If rates continue to rise, it is more than likely that markups in the housing market will be pressured to remain competitive with the higher costs of financing.

As an investor, the situation might seem more pressing. Leading lender Countrywide Credit Industries (NYSE:CFC) reports its earnings on Wednesday. Business has been booming over the last few years. Naturally. The rate spike in recent weeks has probably been good for business, as volatility tends to help the company near term. However, if the basis points keep ticking higher, all bets are off. The incentive to refinance will dwindle and the housing sector may shift from a seller's to a buyer's market.

That doesn't mean that the homebuilders are doomed. While I have argued this in the past, the blue chip residential builders like Lennar (NYSE:LEN) and KB Home (NYSE:KBH) have proven resilient, growing faster than the smaller developers. They may have to keep their premiums in check as borrowing costs climb, but they may still carve out a cozy living by swallowing up market share along the way.

So, yes, ease up on that panic button. If you have refinanced your homestead recently, it's not as if rates ever got that much lower than they were a year ago. But if you ignored the hype and you're still sitting on the fat rates dished out through most of the 1980s and 1990s, maybe it's time to take this matter seriously. That window has been open for so long that it's starting to get chilly around here.

Is this the end of cheap financing? If so, is it time to settle back and work with what you've got? It seems so easy on TV, but can you really remodel your home -- or even your apartment -- on your own? All this and more -- in the Building/Maintaining a Home discussion board. Only on Fool.com.

Longtime Fool contributor Rick Munarriz is happy in his home. He's fallen for the hype, having refinanced twice over the past few years. No mas! He does not own shares in any companies mentioned in this story.