Make a connected-system record
Start with one wide photograph of the mechanical area. Follow it with the furnace label, indoor coil area, filter access, return and supply transitions, thermostat and any outdoor cooling equipment. Include the closed electrical panel and its surroundings; leave covers in place.
The wide view preserves relationships that close label photographs miss. A furnace, water heater, drain and storage may compete for the same room, while refrigerant and electrical routes connect the indoor work to an outdoor location.
State the decision still open
Tell the contractor whether gas backup is acceptable, removing the furnace is a goal, or both paths remain open. That preference guides the alternatives to document. It does not determine capacity, equipment compatibility or electrical feasibility.
Ask for comparable paths
When more than one architecture is proposed, request the same categories for each: retained equipment, new models, cold-weather operation, controls, duct work, electrical work, gas outcome, testing and exclusions. This makes the tradeoff visible without relying on a slogan about fuel choice.