Is retrofit the same as renovation?

No. Retrofit means upgrading a building's performance, mainly its energy efficiency, while renovation covers any work that brings a property back into good condition. Insulating solid walls, fitting better glazing, improving airtightness, adding ventilation with heat recovery, switching to a heat pump: that is retrofit. A new bathroom or a reworked ground floor is renovation.

The two overlap on site more than the definitions suggest. When we strip a Victorian terrace back to brick, that is the cheapest moment to insulate, because the mess and the access are already paid for. Adding wall insulation to a finished house later means wrecking decoration you have just paid for, so we push clients to make the retrofit decision before plastering, not after.

A retrofit can also happen with almost no visible change. We have insulated and re-ventilated flats where the neighbours never knew work had happened, because the fabric changed and the finishes did not. Renovation is rarely that quiet. If your real goal is lower bills and a warmer house, ask for retrofit measures by name when you brief a builder, because a standard renovation quote will not include them by default. The difference between renovation and refurbishment is a separate question, and it is mostly about depth rather than performance.