If you are searching for Denver Office Space, here are some things you should consider to help you find the right location:
1. Business Plan - What is your business plan over the next five years and how does that plan direct your real estate decision?  Many clients do this process backwards - they look for the cheapest space possible and then deal with the limitations of their real estate for the term of their lease.  Fortune 500 companies make sure their business plan informs their real estate decisions. How much staff will you have? How will your client base change as your business grows? Moving is expensive, don't miss this step!
2. Accessibility - Is the office building located in a place that is accessible for you, your employees/vendors, and your clients? Many people forget to consider their client's location needs when selecting office space.
3. Easy Commute - Can you get to the office without feeling frazzled? I am a big proponent for having a main office within 15 minutes of home and setting up virtual locations around Denver for alternate meeting spots.
4. Complimentary Businesses - Are there tenants in the building who will compliment your business? You will interact with these people at building events. Who do you want to be close to?
5. Relationship with Landlord - Is the landlord or the property manager responsive and friendly? These are the people you will call when (not IF) something goes wrong with your space. Will they fix things quickly?
6. Flexibility - Does your business plan over the next two years dictate flexible lease terms? Most landlords in Denver today are asking for 3 to 5 year lease terms. You may need to look for an executive suite or a landlord who will accept a 1-2 year term. They exist, but their are fewer landlords willing to do this than there were a year ago. 
7. Price - Lease rates for office space are typically a full-service gross or modified gross lease rate. In Denver, many office buildings are requiring their tenants to pay budgetary increases in their uncontrollable operating expenses (property taxes, snow removal, operating supplies, etc.). The key questions to ask: "what is included in this lease rate?" "what will I be asked to pay in addition to this lease rate?"
8. Parking - Is the parking lot or covered garage included in the lease rate? Is their enough parking for you, your employees, and your clients?
9. Technology - What internet service provider do you prefer to use? Many Denver area buildings have only one service provider. Need Comcast at your new building? Call them to be sure they can bring service to the building.
10. Get Help - If this whole process seems overwhelming, ask for help. At Execu-Center we are licensed Colorado real estate agents who also specialize in representing Tenants AND executive suite operators. Our fees are typically paid by splitting a commission fee with the Landlord's leasing agent.