This week, Travis County posted 2008 property tax assessments. Across the City of Austin, the assessed value of the average single-family house increased by a significant 12.82%. This is a big jump during a period during where actual property values seem to have increased only modestly.With the new assessment data available online, AustinTowers analyzed Hundreds of downtown condo units in projects such as the Nokonah, Plaza Lofts, and Milago to better understand the current downtown valuation trend. Because units are easy to compare . . .