Building control in Scotland works under its own legislation. The framework is the Building (Scotland) Act 2003 and the Building (Scotland) Regulations 2004, with the technical standards set out in the Scottish Technical Handbooks, Domestic. Guidance written for England and Wales does not apply here.
Nothing below is a ruling on your job. Whether a particular bathroom needs a warrant is decided by the local authority building standards service, which in Glasgow is Glasgow City Council and in the surrounding areas is East Renfrewshire, East Dunbartonshire, Renfrewshire, North Lanarkshire or South Lanarkshire.
What a building warrant is
A building warrant is permission from the local authority to carry out construction work that falls under the Building (Scotland) Regulations 2004. It is granted before work starts, and it confirms the proposals are intended to meet the standards in the Scottish Technical Handbooks. It is separate from planning permission, and a job can need one, both or neither.
When a bathroom usually needs one
A warrant is more likely to be needed where the work changes the building rather than renewing what is already there. In most cases that covers forming a new bathroom or WC where there was not one before, altering or forming new drainage connections, work affecting a structural element such as removing part of a wall, and conversions such as turning a cupboard, box room or part of a loft into a bathroom. Check with building standards before assuming your plan is exempt.
When it usually does not
Straight replacement work generally does not need a warrant. That usually includes replacing a bathroom suite like for like in the same position, retiling, replacing a shower in its existing position and redecorating. Most full bathroom installations in Glasgow that keep the existing layout sit in this category, but the moment the layout or the drainage moves, the position can change.
What happens if you skip one
Unwarranted work tends to catch up with the property at sale. When a Scottish home is sold the Home Report includes a Single Survey with condition ratings, and work carried out without a required warrant and completion certificate can cause problems for the sale. If you are unsure whether past work was warranted, ask your local authority building standards service what options exist.
Tenements and shared soil stacks
In a tenement, the pipework can be a shared matter as well as a warrant question. Pipes serving more than one flat, including a shared soil stack, are usually scheme property under the Tenement Management Scheme in the Tenements (Scotland) Act 2004, so work affecting them can require agreement among owners. Title deeds take precedence over the Tenement Management Scheme where they say something different, so read the deeds first. Our page on bathroom fitters in Shawlands covers how this plays out in the local tenement stock.
Factored buildings
Where a building is factored, the factor should be told about work affecting common parts and access. Property factors are regulated under the Property Factors (Scotland) Act 2011, and notifying them early usually avoids disputes about stairs, close access and shared services later in the job.
Listed buildings and conservation areas
Consent rules sit alongside the warrant system, not inside it. Internal alterations to a listed building can require listed building consent, and external changes such as a new extract vent through a front elevation may require consent in a conservation area. The council planning service, rather than building standards, is the department to ask about both.
Electrical and ventilation standards
Bathroom electrics and extract ventilation are both covered by the Scottish Technical Handbooks. Section 3 Environment covers ventilation and moisture, Section 4 Safety covers electrical safety and slipping, and Section 6 Energy applies where fabric is opened up and insulation is affected.
Scotland has no Part P style self-certification scheme, so domestic electrical work must comply with BS 7671 and you should expect certification from a qualified electrician. We use qualified electricians on our own jobs. Bathrooms require mechanical extract ventilation, and the handbook sets the performance expected, so confirm the specification with building standards where a warrant is involved. Ventilation planning matters just as much on a wet room installation in Glasgow, where the whole room is a wet area.
Completion certificates
Where a warrant is granted, a completion certificate is normally required at the end of the work. Keep it with the property papers, because it is the document that shows a future buyer and their solicitor that the work was carried out under the warrant.
How we handle it
We tell you at survey stage if we think your job needs a warrant, and we will work with your application. The decision rests with your local authority building standards service, and we would always rather raise the question before design is finalised than after the walls are open. For related reading, see our guide to bathroom waterproofing and tanking and our small bathroom design ideas for Glasgow tenement flats.
Common questions
- Does replacing a bathroom suite need a building warrant?
- Usually not, where the new suite goes in the same position as the old one. Like for like replacement, retiling and redecorating are generally treated as repair and renewal rather than alteration, but you should check with your local authority building standards service before work starts.
- Does turning a box room into an en suite need a warrant?
- In most cases yes, because forming a new bathroom or WC where there was not one before is an alteration and normally involves new drainage. Conversions of cupboards, box rooms and loft space fall into the same category, so ask building standards about your specific room before committing to the plan.
- What happens if previous owners did work without a warrant?
- It can cause problems when the property is sold. A Scottish sale requires a Home Report containing a Single Survey with condition ratings, and missing warrants or completion certificates for past work often surface at that point, so speak to your local authority building standards service about what can be done retrospectively.
- Who applies for the building warrant, the homeowner or the fitter?
- The application is made by or on behalf of the property owner, so the responsibility sits with you as the homeowner. We tell you at survey stage if we think your job needs a warrant, and we will work with your application, but the local authority building standards service is the authority on whether one is required.
- Does a tenement flat need the neighbours' agreement?
- It can do, where the work affects common parts. Pipes serving more than one flat, including a shared soil stack, are usually scheme property under the Tenement Management Scheme in the Tenements (Scotland) Act 2004, so altering them can be a common matter needing agreement among owners, and your title deeds take precedence where they say something different.
- Does a building warrant cover electrical work?
- A warrant covers the work described in the application, and electrical safety is dealt with under Section 4 of the Scottish Technical Handbooks. Scotland has no self-certification scheme for domestic electrical work, so the work must comply with BS 7671 and you should expect certification from a qualified electrician.