Since its passage, Proposition 13 prohibits property tax increases until

      property ownership is changed.

      If either spouse is over age 55 (when the old home is sold), PROP 60 
      allows replacement of a primary residence with a new home of equal or 
      lesser value (but see below) within the same county and transfer of the 
      Prop 13 assessed valuation from the old home to the new property.  This 
      is allowed once in your lifetime, and a spouse who has done it before 
      'taints' both spouses.

      PROP 90 allows counties to elect to accept transfers of Prop 13 values for 
      moves from other counties when a primary residence is replaced with a 
      less expensive (but see below) home. If you are over 55 and move into a 
      county which accepts Prop 90, you may take your old, lower Prop 13 
      value, regardless of from which county you move. 

      Using Prop 90, you can sell your $400,000 San Francisco home 
      [assessed value $80,000] and move to a new $300,000 home in San Mateo;
      the new San Mateo assessed value will be $80,000!

7 COUNTIES WHICH ACCEPT PROP 90 (Current as of 6/1/2005)

      Alameda,  Los Angeles, Orange, San Diego, San Mateo, Santa Clara, and
      Ventura. [Contra Costa, Inyo, Kern, Riverside, Modoc, Monterey, and 
      Marin have dropped out of the Prop 90 program.]

      Props 60 and 90 apply if you "trade down" (i.e. the new home costs less 
      than the sales price of the old home). 

  >  If you buy New Home 1^st; then sell the Old Home, you must go down 
      in price.

  >  If you sell the Old Home1st; then buy the New Home: 

•         In 1^st 365 days after the sale of Old Home, you may go up 5%
   in the purchase price of New Home.
•         If you buy New Home more than 1 year from the sale of Old
  Home, but less than 2 years, you may go up 10%.
  
  

      Some buyers can pay the commission outside of escrow to lower to sales price.