I never ever thought I'd do this, but I just got off the phone with an insurance agent of one of my clients asking me how to insure a loft.
Lofts are Condominiums, and therefore require a homeowner's policy known in the insurance industry as an HO-6 (Condominium Policy). Don't buy a renters policy unless you are renting!
These policies generally cover your belongings, liability, medical payments, and a small amount of money for the portion of the building not covered by the "master" policy that covers your condominium. I usually advise increasing that amount to at least 15-20% of the value of the condo because the items that are usually covered in the event of a loss can include flooring, cabinetry, trim, wall finishing and paint, and even lighting.
I also recommend an endorsement called "loss assessment coverage."
Ultimately, work with an agent familiar with lofts and the possible areas of coverage that exist. Email me for a referral request (specify insurance referral). I work with some great agents that know exactly what to do.