The typical asking rate per listing is in the $10's per square foot per year. The Glen Allen region is going through a a boost in rates. In the last 3 months, the median rate rose $15 per sqft per year. That's a Inf% increase in rent.
In the last 90 days, 6 listings have been posted online, which means new listings most likley are leasing quickly. You'll want to be prepared to tour spaces as quick as possible. About 17% of the listings in the Glen Allen are subleases, so you might be able to find a shorter term or below market rent. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,500 sqft. Most properties in this area are approximately 1 stories. Most buildings in this area were built in 2001 and are Class A.