A retrofit is an assessment, not a kit
Existing wiring, fitting types and access shape what is practical. There may be useful options involving compatible replacement controls, wireless devices or plug-in equipment, but no single approach suits every home.
I start with the desired behaviour and the current installation. The electrician assesses fixed electrical changes. That keeps the scope grounded in what can actually be delivered.
Start with one useful problem
An awkward set of switches, a dark entry or blinds that need a daily routine can be a good starting point. Prove the benefit in a contained area before extending the system.
Check the less exciting details: battery changes, wireless coverage, equipment access and what happens when the network is unavailable. A small retrofit still needs a maintenance plan.
Keep it useful for the next person
For a rental, agree permissions before alterations and consider reversible options. For any home, preserve clear everyday controls and document the installed equipment.
The best retrofit is not necessarily the one with the most automation. It is the one that solves a real problem with a proportionate amount of change.