The short answer
Usually yes. Cutting a new skylight into a roof that already stands is building work, so Building Control approval is needed. Taking out and renewing the complete rooflight or roof window is notifiable too. Changing only the sealed glass unit inside a frame that stays is not. Where your job is notifiable, we submit the Building Control notification as part of fitting it.
New rooflights in an existing roof
Cutting an opening means trimming rafters or joists, which is a structural alteration. The new window also has to meet Part L of the Building Regulations, the part dealing with the conservation of fuel and power, so it must reach the limiting U-values published in Approved Document L (Volume 1, edition 2021). The work therefore goes through Building Control, either as a Building Notice or with a full plans application, and it is inspected.
Other parts of the regulations can come into play depending on the room. A rooflight in a loft room may be intended as an escape window, in which case size and position rules in Part B (fire safety) apply. An opening rooflight can contribute to ventilation under Part F. A rooflight near a boundary may be subject to fire-spread rules as well. These points are checked at the survey, not left to chance on the day.
Replacing a rooflight or roof window
A replacement of the whole unit is still notifiable. A window counts as a controlled fitting under the regulations, so the new one must meet the energy efficiency requirements of Part L. The work is either notified to Building Control, or self-certified by an installer who is registered under a competent person scheme.
Many people are surprised by this, because a swap feels like maintenance. The rule exists because old windows are generally far less efficient than current ones, and a replacement is the moment to meet the standard. Our guide to replacing an old skylight goes through what the swap involves.
Where approval is not needed
Where only the sealed glass unit is replaced and the frame itself is left in place, there is nothing to notify. This is the usual route for a misted double-glazed unit where the frame is sound. Nor is any minor work that doesn't involve a new window or a structural change, such as redecorating the lining.
If you're unsure which side of the line your job falls, the question to ask is simple: is a window, frame included, being installed, or is the roof being cut? If either is true, expect the work to be notifiable.
Building Regulations and planning are separate
Planning permission is a different system, and one doesn't replace the other. Planning rules usually let a house rooflight go in as permitted development if it sticks out no further than 150mm from the roof plane and stays below the highest point of the roof. A side-facing window in the roof has to be obscure-glazed and fixed shut unless its opening part sits over 1.7m from the floor. Conservation areas, listed buildings, flats and national park land follow other rules, and an Article 4 direction can remove the rights altogether.
The local planning authority is the place to check. In the Exeter area, that may be Exeter City Council, East Devon, Mid Devon, Teignbridge or Torbay Council, or one of the national park authorities, depending on the address. Our page on rooflight planning and Building Regulations in Devon sets out the position in more detail. Planning consent for the work is the homeowner's responsibility, and Building Control approval doesn't replace it.
What we handle, and what you receive
You do not need to chase the notification: for notifiable work we file it ourselves. Fitting follows current Building Regulations, and our quote paperwork notes how the roof and ceiling are built up, plus how the lining is formed and finished.
When the job is complete, you will usually receive a completion certificate from Building Control or, where the installer self-certifies, a certificate confirming compliance. Keep it with the house papers. Solicitors often ask for it when a property is sold, and a missing certificate for a rooflight can slow a sale.
Who can notify, and when
There are three ways the notification can be made. The first is through the local authority Building Control team, which receives the application, may inspect the work and issues a completion certificate. The second is through a registered building control approver (the private-sector route, renamed under the Building Safety Act 2022), which does the same job. The third route applies to certain replacements only: an installer registered with a competent person scheme can self-certify, and the local authority is informed afterwards.
On the first two routes, the application goes in before work starts; a Building Notice to the council needs at least two days' notice. On the third, the registered installer notifies the job within 30 days of finishing it. Getting approval after unnotified work is possible, through a regularisation application, but it is slower and may mean opening up finished work for inspection. That is why we set it up at the start of the job.
What inspectors look at
On a new opening, an inspector is usually interested in the structure around the cut: the trimmers, the bearing of the rafters, and how the load is carried. They also look at the thermal performance of the unit, and at the insulation around the lining, since a gap there is a cold bridge. For a loft room, they check the escape and ventilation requirements. For a replacement, the main points are the unit's rating and the way it is fixed and flashed.
The finish inside is not the inspector's concern, but it is ours, so the lining, plaster and paint line are specified in the finish schedule alongside the regulated parts of the job.
What to do next
If you're thinking of adding or replacing a rooflight, you don't have to settle the regulations first. Send us the details through the form and we will confirm what is notifiable for your roof once we have seen it. Timings are covered in how long it takes to fit a skylight, and old ceilings in fitting one in lath and plaster.
Official guidance is on the Planning Portal. To start, ask for a quote.