The product you're being pointed toward is a builder's risk policy, sometimes sold as course of construction coverage. It insures a building while it's under renovation, including materials sitting on site and often theft of those materials, which is a real risk on a gut because copper and appliances walk. A standard landlord or homeowner policy is written for an occupied, finished house, and most of them have a vacancy clause that cuts off or limits coverage once nobody lives there for something like 30 or 60 days. Your agent was right to send you elsewhere.
Two things people set up wrong. First, the amount insured on builder's risk should track what it would cost to rebuild the structure, not the after repair value you hope to sell at, and if you underinsure it the claim gets reduced. Second, you carry general liability yourself and you also collect a certificate of insurance from every contractor showing their own liability and workers comp, sent by their carrier rather than a PDF they email you. If an uninsured worker gets hurt on your job, that lands on you.
The part that catches first timers is the term. Builder's risk is usually written for a fixed period, six or twelve months, and extending it costs money and sometimes triggers questions about why the job stalled. Since guidance on gut jobs is to model 120 to 150 days of work rather than 90, buy the longer term at the start. Get the vacancy language and the term in writing from the carrier, and check who can legally pull the permits, because whether an owner can permit their own gut varies by state.
