If you are planning an extension, loft conversion, or major renovation in London this year, the regulatory landscape matters as much as your design ideas. Here is a practical overview of what homeowners should know in 2026.
Building safety expectations are higher
Since the Building Safety Act came fully into force, building control has become stricter at every level, not just for high-rise buildings. Documentation is checked more carefully, and the days of sorting out paperwork after the build are over. A complete, accurate drawing package before work starts is now the single best way to avoid delays.
Permitted development still does a lot of work
Many single-storey rear extensions, loft conversions and outbuildings can still be built under permitted development rights, without a full planning application. The rules are detailed, though, and vary with property type, conservation areas and previous alterations. A short feasibility check before you commit to a design can save months.
Energy efficiency requirements keep rising
Part L of the Building Regulations continues to push new work towards better insulation, better glazing and lower carbon heating. For extensions, this affects everything from wall build-ups to the percentage of glazing you can use. Designing to the standard from day one is far cheaper than redesigning after a building control query.
Councils are stretched, so applications must be right first time
London planning departments continue to run with limited resources. Incomplete or inconsistent applications go to the back of the queue. Clean drawings, correct forms and complete supporting documents are the difference between an eight-week decision and a six-month saga.
Our advice
Get the survey done, get the drawings right and involve building control early. At Unsel Consultancy we prepare planning and building regulation packages for London homeowners and manage the application from start to approval. Read more about our approval consultancy or contact us for advice on your project.