In the UK, planning permission is not typically required for installing a kitchen, but it's important to consider building regulations approval. This approval is necessary for significant alterations such as moving key fixtures like the sink, installing or extending drainage systems, creating a new utility room, or carrying out electrical works. It's also required if you're building a kitchen where there wasn't one before or knocking down any walls, to ensure compliance with ventilation, drainage, structural stability, and safety standards. However, if your kitchen refurbishment involves more superficial changes, like replacing kitchen units, doors, or drainage fittings with similar ones, then building regulations approval is generally not needed. As the specific requirements can vary, it's crucial to consult with your local building control team for guidance tailored to your project. They can provide definitive answers and ensure your kitchen project complies with all necessary regulations.