The typical asking rate per listing is in the $20's per square foot per year. The Lewisville region is experiencing a a rise in rates. In the last 3 months, the median rate increased $2 per sqft per year. That's a 9% rise in rent.
Compared to the rest of the DFW Metroplex market, the Lewisville region has less expensive rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 12 listings have been made available, which means new listings are probably going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,160 sqft. Most properties in this area are around 1 floors. Most buildings in this area were built in 2000 and are Class B.