People use "renovation" and "refurbishment" fairly loosely, but they usually describe two different pieces of work, and it's worth knowing which one you actually need before you get quotes.
A refresh keeps the existing layout. The suite, tiling and flooring are replaced like for like, pipework stays broadly where it is, and the room gets a new lease of life in around two weeks. It's the most cost-effective option when the layout already works and it's simply the finishes that have aged.
A full refurbishment strips the room back and reworks it. Fixtures move, waste and supply pipework is re-run, walls are prepared or re-boarded, wet areas are tanked, electrics and ventilation are upgraded and everything is retiled. It takes longer — typically three to four weeks — but it's the only way to fix a layout that has never really worked. If you're going that far, it's effectively a complete bathroom installation, and we'll quote it as one.