Beyond Planning Permission: Building Control and How It Affects Your Renovation

One of the most common misconceptions we encounter is that getting planning permission is the hardest part of a renovation. In reality, planning is just the beginning. What happens after permission is granted, during the build itself, is where the quality of your project is truly determined.

Building control is not optional

Any significant work to your home, whether that is an extension, a loft conversion, structural alterations, or changes to electrics and drainage, will require building control approval. This is separate from planning permission and is a legal requirement. Its purpose is to ensure the work meets current building regulations covering structural safety, fire escape provisions, ventilation, and energy efficiency.

You have two options: a building control officer from your local authority, or an approved inspector from a private company. Either will visit at key stages of the build and issue a completion certificate at the end. That certificate matters. Without it, selling your property becomes complicated, and your buildings insurance could be affected.

A good architect will manage this process on your behalf, liaising with the building control officer and ensuring your contractor knows what is required and when.

Regulations set the minimum. Good architects and builders go further.

Building regulations define a floor, not a ceiling. A project can be fully compliant and still be poorly built. In our experience, what separates a renovation that lasts from one that causes problems within a few years is the quality of materials used and the skill of the people carrying out the work.

This matters particularly in London, where the vast majority of residential properties are old. Victorian and Edwardian houses, period conversions, and interwar semis all come with their own characteristics and vulnerabilities. Good workmanship means understanding the building you are working with, not simply overlaying it with modern finishes and hoping for the best.

Insulation is where false economies are most costly

Energy efficiency requirements have become significantly more demanding in recent years, and for good reason. For extensions and renovations to existing homes, the regulations set minimum standards for insulation in new walls, roofs, and floors, as well as for any heating systems being installed.

We always recommend exceeding those minimums where possible. Poor insulation is one of the most expensive mistakes to rectify after a build is complete. It affects how comfortable your home is day to day, how much you spend on heating, and increasingly, how your property is valued on the market. Spending a little more during the build to get it right is almost always the better decision.

What this means for your budget

It is tempting, particularly when budgets are under pressure, to look for savings in areas like building control oversight or material quality. In our experience, that is rarely where savings should be made. The visible finishes, the kitchen, the lighting, the flooring, those are where you have more flexibility. The structure, the insulation, and the workmanship underneath are what you will be living with for decades, whether you can see them or not. Planning permission gets your project started. Building control is what ensures it is done properly.