Where should the next efficiency dollars go before we finalize the design?

The uncertain PV-production estimate makes it worth separating “buy panels now” from “keep solar easy to add later.” Roof layout, conduit routes, and electrical capacity are decisions to coordinate during design, though what’s practical depends on the roof and electrical plan. By contrast, air-sealing details and insulation continuity can be costly to fix after finishes go in, and window choices are harder to revisit once installed. Which PV-ready provisions can the designer confirm now, and what would they cost compared with installing the extra capacity upfront?