Most of what comes up when you search this question is written for England. It gets repeated on Scottish company websites by people who have never checked, and it leads homeowners in Lanarkshire to worry about paperwork that doesn’t apply to them, while occasionally missing the paperwork that does.
What follows is a general description of how the Scottish system is set up. It is not legal advice and it can’t be, because the answer for any particular job depends on the property, what’s being done to it and where it sits. The building standards department at your council is the body that confirms what your specific job needs, and they will tell you over the phone. If your property is listed or in a conservation area, that’s a separate conversation with the council as well.
With that said, here’s the shape of it.
FENSA and CERTASS do not operate in Scotland
This is the one worth getting into your head first.
FENSA and CERTASS are self certification schemes that sit under the building regulations for England and Wales. They exist so that a window installer down south can certify their own compliance with those regulations rather than involving the local authority for every job.
Scotland has its own building legislation, entirely separate, and those schemes have no standing under it. There is no FENSA certificate for a window fitted in Wishaw, because there is no FENSA in Scotland to issue one.
So if a salesman on your doorstep tells you the job comes with a FENSA certificate, he is reading English material. It doesn’t necessarily make him a bad installer. It does tell you he hasn’t checked, which is a fair thing to weigh up.
What Scotland runs on instead
Scotland works to the Scottish Building Standards, set nationally, and the mechanism for enforcing them is the building warrant, applied for from and granted by the local council. Round here that’s North Lanarkshire Council or South Lanarkshire Council depending on which side of the line you’re on.
A warrant is permission to carry out the work, obtained before it starts, followed by a completion process with the council when it’s finished.
The critical distinction is that needing a warrant and needing to comply with the standards are two different things. Plenty of work has to meet the standards without needing a warrant to do it. Not requiring a warrant is not permission to fit something substandard.
Where different jobs generally fall
These are the broad categories. Confirm your own with the council.
Replacing the glass in an existing frame is a repair. Swapping a misted or blown sealed unit for a new one of the same type is maintenance of an existing building, and it is not a building warrant matter. This is the great majority of what we do, and nobody needs to apply for anything.
Replacing whole windows in existing openings is the one people ask about most. In most ordinary domestic cases this is generally treated as work that must comply with the relevant standards, covering things like the thermal performance of the new window, safety glazing where it’s needed and escape provision from bedrooms, without a building warrant being required for the replacement itself. The obligation to meet the standards is still there. The application process usually isn’t.
Forming a new opening in a wall, or enlarging or altering an existing one, is a different animal. Once you’re cutting into the structure you’re into work that does require a warrant. Turning a window into a set of patio doors, dropping a cill to make a window taller, punching a new window into a gable: all of that is structural alteration and needs to go through the council properly.
Listed buildings and conservation areas sit on top of all of the above as a separate consent from the council’s planning side. There are listed properties and conservation areas across Lanarkshire, and on those the question isn’t only whether the window performs, it’s whether you’re allowed to change its appearance at all. Swapping timber sash and case windows for uPVC in a conservation area is exactly the sort of thing that gets refused. If you’re in any doubt about the status of your property, ask before you order anything.
The standards that apply no matter what
Two of these come up constantly and both are genuine safety matters rather than bureaucracy.
Safety glazing. Glass in and immediately beside doors, and glass at low level near the floor, has to be safety glass, meaning toughened or laminated. Toughened glass breaks into small blunt granules instead of long blades. Laminated holds together on a plastic interlayer. Either is fine, ordinary annealed float glass in those positions is not, and this applies whether anyone has filled in a form or not.
Escape windows. Habitable rooms, bedrooms in particular, generally need a window that opens enough for someone to get out in a fire and for a firefighter to get in. This matters most when replacing an old window, because it is entirely possible to fit a modern one into the same hole and end up with a smaller clear opening than before, particularly if a large single opener becomes two smaller ones. Ask anyone replacing bedroom windows whether they’ve checked it.
Self certification in Scotland
Scotland does have its own arrangements for certification of construction, where an approved firm can certify that particular work complies with the standards rather than everything being checked individually by the council. These are approved through the Scottish system, are not the same as the English ones, and vary by trade and by type of work.
We’d rather point you at the council than overstate our knowledge of schemes we’re not part of. If an installer tells you they can self certify, ask them which scheme and for what type of work, then take two minutes to check it exists.
The short version
Glass in an existing frame: a repair, nothing to apply for. Whole windows in existing holes: must meet the standards, generally no warrant in ordinary domestic cases. Changing the size or position of an opening: warrant territory. Listed or conservation: ask first, before you spend anything. Safety glass and escape openings: always, everywhere.
And if anyone mentions FENSA, they’re quoting the wrong country at you.
If you’re not sure which category your job falls into, your council’s building standards team is the right first call and it costs nothing. If it turns out to be glass in an existing frame, which it usually is, send us a photo on WhatsApp or ring 01698 604 278 and we’ll tell you what’s involved.
Anything we fit as a replacement window meets the current Scottish standards, so you are not left working that out for yourself.
Related advice
- How long uPVC windows last
- Toughened or laminated glass
- What a guarantee actually covers
- Secondary glazing or new windows
See our vertical sliding windows page for what we do and where. Not sure? Ask us, there is no charge for looking.
Stuck on something else? Our window and door advice section covers around fifty of the faults we see most.
Written by the team at Wishaw Window Repairs. Over thirty years repairing uPVC windows and doors across Lanarkshire.