Q: How early is too early to start thinking about new space or negotiating a renewal?
A: It almost never is, with some qualifiers
For a more precise answer, a general rule of thumb that I like to use if you have a relatively straight-forward need is to start at least six months before your current lease expiration, and preferably about 12-18 months, depending on the situation.
The Case for More Time
If you are considering a purchase, development of a new building, or have complex and specific needs (ex: rail access, 100,000+ SF, the need for a 'main and main' location in an extremely competitive market, etc), then 12-18 months is probably the minimum and might still not be enough.
The Case for Less Time
If you have a smaller (1,000-10,000 SF) need that is relatively simple and you are willing to be flexible on things to allow moving into previously built-out space, you may be able to complete the process in as little as about 3 months. That being said, it will take a commitment to moving everything as quickly as possible.
Just remember that, as the tenant, time is on the landlord's side and as you get closer to the expiration of your current lease, you will lose leverage.
The Case for More Time
If you are considering a purchase, development of a new building, or have complex and specific needs (ex: rail access, 100,000+ SF, the need for a 'main and main' location in an extremely competitive market, etc), then 12-18 months is probably the minimum and might still not be enough.
The Case for Less Time
If you have a smaller (1,000-10,000 SF) need that is relatively simple and you are willing to be flexible on things to allow moving into previously built-out space, you may be able to complete the process in as little as about 3 months. That being said, it will take a commitment to moving everything as quickly as possible.
Just remember that, as the tenant, time is on the landlord's side and as you get closer to the expiration of your current lease, you will lose leverage.