Planning and Building Control for Conservatories Explained

If there is one thing you want to avoid, it’s a dust-up with the local planning department about whether or not your brand new conservatory is legal or not. The costs, not to mention the stress, will be sure to take the shine off your recently completed pride and joy.

So, how exactly do you stay on the right side of the line with it comes to planning?

Right back at the first stages, you should have considered if your conservatory needed planning permission. Even if you’re just planning an upgrade to an insulated conservatory roof, it’s something you’ll need to think about. Put simply (this is informal guidance, you should confirm with an architect before starting any construction) you’ll stay clear of requiring planning if:

• If less than 50% of the existing land, before any new construction, is to be covered (including other buildings)

• The conservatory is not beyond the front or side of the house that faces onto a road

Additionally, depending on which side the conservatory is to be built, you’ll be limited to size, relative to the main existing building and it’ll need to be single storey.

So, you didn’t need planning permission? Well, that’s great! However, don’t get too excited, you still may need to build to building control standards.

Building Control standards apply to nearly all building projects and ensure that government-approved standards are met in regards to the minimum quality of construction. Building control is required when you breach the thermal break of the property (basically make a hole in an external wall, or extend the existing heating circuit) or alternatively if the conservatory is over 30sqm. You can read more about building control & planning here.

Our advice is not to make such a breach. Once you do, the costs can start to spiral.

SAP calculations would be required looking at the before and after effects and would cost in the region of £750.

• Building control costs can be around £600 and will now need to include a couple of site visits

• If you’re increasing the weight to the roof, you’ll need to expose the footings for inspection by a building control inspector which raise the labour costs yet again.

• Certain boroughs will require elevational plans, for which you’ll need to engage an architect, which could reach costs in excess of £750

So, for the above reasons, we always advise keeping thermal separation between the house and the property. It’s a sure-fire way to keep the costs down.

Recent inspections by building control officers have seen cases that failed to meet standards and were therefore rightly deemed substandard and, in the worst examples, downright dangerous. This has led to increased vigilance by local authority building control departments. Avoiding any issues is obviously vitally important, you’ll be glad to know All Seasons Roof carry a 100% success record in this regard!

If your conservatory is a tiled roof design and additionally requires building design, we are most often asked to satisfy building control on three main points:

  1. Conservatory roof insulation
  2. Loading of the conservatory roof
  3. Condensation risk


As leaders in the conservatory roofing industry, we’ve worked on nearly every type of conservatory you could imagine. We’re more than happy to take a look at your chosen conservatory design and offer advice. Call our installations team today and get our helpful ‘no pressure” advice on your dream conservatory.