Most listings are in the $20's per square foot per year. The Irving submarket is seeing a a boost in rates. In the last 3 months, the median rate increased $0 per sqft per year. That's a 1% increase in rent.
Compared to the rest of the DFW Metroplex market, the Irving submarket has more expensive rates, and you'll need to make a great offer to be in this hot region.
In the last 90 days, 462 listings have been made available, so you'll want to check back regularly for new listings. About 3% of the listings in the Irving are subleases, so you will probably need to consider the implications of signing a direct lease with the building. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 970 sqft. Most buildings in this region are approximately 2 stories. Most buildings in this market were built in 1985 and are Class B.