No, they aren't compulsary but depending on the scale of the project, it's always a good idea to have drawings present to ensure everyone is on the same page. These however, don't always have to be CAD produced, a simple hand drawn plan can work on smaller projects.

Yes, electrical designs and drawings can be tailored to accommodate future expansions or upgrades. Professionals can include provisions for additional circuits, wiring conduits, or increased power capacity in the designs. This flexibility allows your smart home infrastructure to adapt to future advancements and evolving needs with minimal modifications.

Electrical designs are a comprehensive map of all the facets of you project. They include; wiring routes and containments, distribution boards and circuit schedules, sockets, switches and switch gear, lighting fixtures and accessories to name a few.