UK Building Regulations 2010: Regulation 40A Solar Guide
Updated 6 September 2026 · By SolarNevs Research Desk, Dealer surveys + verified sources · 1 source · Method ↗
Key Takeaways
- UK S.I. 2021/1391 inserts Regulation 40A and Regulation 44ZA into the Building Regulations 2010 for on-site electricity generation systems.
- Mandates that installers deliver comprehensive operation and maintenance (O&M) documentation to the building owner within 5 days of completion.
- Requires systems to be configured to produce the maximum electricity reasonable in the circumstances and deliver it to optimal loads.
- Enforces mandatory written commissioning notices to the local authority building control under Regulation 44ZA.
- Practical technical requirements are governed by Approved Document L Volumes 1 and 2 (2021 editions).
Statutory Scope of Regulation 40A
Enacted through The Building etc. (Amendment) (England) Regulations 2021 (S.I. 2021/1391), Regulation 40A applies to all building work subject to Schedule 1 paragraph L2 (on-site electricity generation).
The regulation establishes statutory handover duties ensuring building owners have the technical tools required to maintain peak solar photovoltaic (PV) generation and storage dispatch over multi-decade operational lifecycles.
Handover & Commissioning Compliance Framework
Building contractors and MCS installers must execute two statutory deliverables:
Regulatory Step | Statutory Requirement | Statutory Reference |
|---|---|---|
Owner O&M Handover | Deliver sufficient operation and maintenance information within 5 days of completion | Regulation 40A(2) |
Performance Standard | System must produce maximum reasonable electricity and deliver to optimal place of use | Regulation 40A(2) |
Local Authority Notice | Issue written notice confirming on-site generation commissioning | Regulation 44ZA(2) |
Statutory Scope | Applies to all installations subject to Schedule 1 paragraph L2 requirements | Regulation 40A(1) |
Guidance Standard | Practical execution in accordance with Approved Document L (Vols 1 & 2, 2021) | S.I. 2021/1391 Explanatory Note |
Installer Obligations for Solar Handover Packs
To satisfy Regulation 40A and obtain final building control sign-off:
- 5-Day Documentation Window: Provide the building owner with inverter manuals, array layout diagrams, warranty certificates, and maintenance schedules within five calendar days of commissioning.
- Optimal Delivery Configuration: Verify that solar generation is prioritised for on-site self-consumption or battery storage before grid export.
- Regulation 44ZA Notice: Submit the formal commissioning notice to Local Authority Building Control (LABC) or the approved inspector alongside the electrical test certificates.
Frequently asked questions
What is the statutory deadline to provide solar O&M information to the building owner under Regulation 40A?
Under Regulation 40A(2), the person carrying out the work must provide sufficient operating and maintenance information to the owner not later than five days after the work has been completed (August 2026).
What performance standard must on-site electricity generation systems meet under Regulation 40A?
The information must enable the system to be operated and maintained to produce the maximum electricity reasonable in the circumstances and deliver it to the optimal place for use (August 2026).
What notice must be given to the local authority under Regulation 44ZA?
Under Regulation 44ZA(2), the person carrying out the work must give the relevant local authority a notice confirming that the system for on-site electricity generation has been commissioned (August 2026).
Which statutory guidance document outlines practical compliance with Regulation 40A?
Practical compliance guidance is published in Approved Document L Volumes 1 and 2 (2021 editions) under the Building Act 1984 (August 2026).
References
- UK Legislation: S.I. 2021/1391 — accessed 31 August 2026
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