Journey
Building regulations compliance for renovation
Navigate building control approval, thermal upgrade requirements, and competent person schemes when renovating business premises
About this guidance
This journey is for business owners undertaking renovation, refurbishment, or fit-out of commercial or mixed-use premises. It covers when you need building control approval, what triggers thermal upgrade requirements, and how competent person schemes can streamline compliance.
Building regulations apply to most structural, thermal, electrical, and drainage work. Even work that doesn't require planning permission may need building control sign-off. The consequences of non-compliance include remedial orders, difficulty selling or letting the property, and insurance complications.
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Does your work need building control approval?
Not all renovation work requires building control involvement, but most structural alterations, thermal upgrades, new drainage, and electrical installations do. The first step is to establish whether your project falls within scope.
Check if you need building control approval
Understand which types of work require approval, exemptions, and how to submit a building notice or full plans application
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Check if thermal upgrades are triggered
If your renovation involves work on a thermal element (walls, roof, floor, windows, or doors), you may trigger an obligation to upgrade that element to current thermal performance standards. This is known as the thermal element upgrade trigger.
Understand thermal element compliance
Learn when renovation work triggers Part L thermal upgrade requirements and what U-values your building envelope must achieve
Window and door replacement requirements
Check U-value requirements, energy ratings, and building control notification obligations for window and door replacements
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Engage competent installers or notify building control
Once you've established what approvals are needed, you have a choice: hire installers registered with a competent person scheme (who can self-certify), or notify building control and arrange inspections yourself.
Electrical work and Part P compliance
Understand which electrical installations require building control notification and how Part P competent person schemes work
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Complete insulation and heating upgrades
If your renovation has triggered thermal upgrade requirements, you'll need to ensure walls, roofs, or floors are insulated to current standards. This may involve external wall insulation, cavity fill, loft insulation top-up, or floor insulation installation.
Insulation requirements and installation standards
Learn about U-value targets, insulation types, and installation quality standards for walls, roofs, and floors
Heating system compliance and efficiency standards
Check boiler efficiency requirements, heat pump installation rules, and controls compliance for new and replacement heating systems
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Obtain completion certificates and document compliance
Once work is complete, you must obtain a completion certificate from building control or a certificate of compliance from your competent person scheme installer. Retain these documents permanently—they're required for property sales, lease assignments, and insurance purposes.
What to keep
- Building control completion certificate – issued by local authority or registered building control approver after final inspection
- Competent person scheme certificates – from FENSA, CERTASS, NICEIC, or other scheme installers
- Thermal performance calculations – SAP or SBEM reports demonstrating Part L compliance
- Product specifications – insulation certificates, window U-values, boiler ErP ratings
- Electrical installation certificates – if Part P notifiable work was carried out
These documents form part of your property's compliance record and should be passed to any future buyer or tenant.