Avoiding Capital Gains On Vacation Property
I own a vacation home but rent where I'm currently living. The vacation home has appreciated quite a bit and I'd like to cash it in to help buy a primary residence where I live. Can I sell it as my 'primary residence', even if I'm not living in it, as a way to avoid the capital gains tax? 
Short answer is NO.
The capital gains exclusion is only available on the sale of your primary residence -- it's not a primary residence if you don't live there. You do benefit from a small tax break, however. Your maximum capital gains tax rate is now 15%; but, if your marginal tax bracket is 15% (or lower), then your capital gains tax rate is reduced to 5%.