APPLE VALLEY — After aggressively pursuing home construction loans during boom years, High Desert Federal Credit Union is now reeling from the weak real estate market. Moreover, asking your lender whether a rate if fixed or adjustable is important when you're on the look out for the best rate. Remember that adjustable rates, despite their low interest rates, might not have the best mortgage rates. Adjustable rate mortgages only have low interest rates in their first year, after which, rates either tend to go up or go down.