When a tenant needs to expand, the first thing many of them do is call their landlord and ask for more space. That approach may appear simpler, but here is why it will cost you money:

1. No leverage. The landlord knows when he gets the call from you that you have no intention of moving or being creative. You're most likely not going to split your operation and open a second office. You aren't working with a tenant representative, so you're not seeing the hidden opportunities in the market. You're not evaluating other deal structures on a comparable track, so the landlord will get away with passing on a lot of hidden costs.

2. Buildout Costs. So the space the landlord is offering you may work well without much work. You accept it when they say they'll take care of the cosmetic finishes and maybe an office or two that you need to have constructed. After you sign the lease, perhaps the landlord's permit gets rejected because the common area bathrooms are either too small or inaccessible. The city may require modifications. Who pays for this? Then, you realize the space does not have enough outlets for workstations, equipment, etc, but also it doesn't have enough power. Who pays for the upgrade? Then, you move in and the HVAC isn't working properly. Who pays to upgrade the system? The answer to all of the above is you do, because you didn't think to negotiate it. You only "negotiated" what the landlord put in front of you.

3. Leaving Money on the Table. Many Tenants do not use expanding as an opportunity to renegotiate the terms of the lease. Why leave the terms for your existing space unchanged? It goes beyond the rate. How well are you protected from your landlord's default? How are passthroughs treated? What rights do you have to expand, contract or renew? What other concessions are available?