On average, listings lease in the $20's per square foot per year. The Littleton region is seeing a decline in rates. In the last 3 months, the median rate decreased $1 per sqft per year. That's a 3% decrease in rent.
Compared to the rest of the Denver Metro market, the Littleton submarket has higher rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 10 listings have been posted online, which means leases might be going fast. You'll want to be prepared to make an offer immediately. About 10% of the listings in the Littleton are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 2,150 sqft. Most properties in this market are around 2 stories. Most buildings in this area were built in 1983 and are Class B.