How to Specify a Solar Carport for Building Control Submission in the UK
- Keith Lin
- Mar 24
- 4 min read
Updated: Apr 9
Last updated: 24 March 2026
A solar carport is a structural steel canopy supporting PV panels over a car park. Even where planning permission is not required (under Class OA permitted development), the structure must comply with the Building Regulations 2010 and relevant British/European Standards. This guide covers what you need to prepare for a successful Building Control submission.
Building Regulations vs Planning Permission
These are two separate legal requirements. Planning permission (or prior approval under Class OA) addresses whether you are allowed to build the structure. Building Regulations address whether the structure is safe, structurally sound, and compliant with construction standards.
A solar carport triggers the following parts of the Building Regulations 2010:
Part A (Structure): Structural design, loadings, foundations, frame stability
Part B (Fire Safety): Fire spread to boundaries (relevant if near other buildings)
Part H (Drainage): Surface water management (if over permeable surfaces)
Part K (Protection from Falling): Edge protection if maintenance access is required at height
Part P (Electrical Safety): PV electrical installation, grid connection
Source: Approved Documents — GOV.UK
The Building Control Submission Package
Your Building Control body (either your Local Authority Building Control or an Approved Inspector) will require the following documentation before work begins:
1. Structural Engineer's Calculations
A full set of structural calculations prepared or checked by a qualified structural engineer (CEng MIStructE or IEng MIStructE). The calculations must cover:
Loading: Dead loads (self-weight of frame, panels, cabling — typically 0.15–0.25 kN/m² for panels and 0.3–0.6 kN/m² for steelwork). Imposed loads (maintenance access — 0.6 kN/m² minimum per BS EN 1991-1-1 Category H). Snow loading (BS EN 1991-1-3 UK National Annex — 0.4–0.6 kN/m² lowland England, 0.6–1.2 kN/m² Scotland/upland). Wind loading (BS EN 1991-1-4 UK National Annex — typical net pressures ±1.0–2.5 kN/m² on monopitch canopy).
Frame design: Column design (axial load, bending, buckling), rafter/beam design (bending, shear, deflection), purlin design, bracing design (lateral stability), connection design (bolted connections, base plates, moment connections).
Foundation design: Pad footings, strip footings, piled foundations, or ground screws. Bearing capacity assessment based on site investigation data. Foundation plan with setting-out dimensions.
2. General Arrangement Drawings
Scale drawings (typically 1:100 or 1:200) showing plan view with column grid, elevations with heights and panel angles, sections showing structural depths and foundation details, and setting-out dimensions.
3. Fabrication Drawings
Detailed drawings (typically 1:10 or 1:20) for each fabricated component: column details, rafter details, purlin details, bracing details, and base plate details with anchor bolt positions.4. EN 1090-1 Declaration of Performance
The structural frame must be manufactured by an EN 1090-1 certified fabricator. The Declaration of Performance (DoP) confirms the manufacturer's identity and FPC certificate number, the Execution Class (EXC2 for commercial carports), the steel grade (S355 J2 typical), the reference to BS EN 1993-1-1, and CE or UKCA marking. Without a valid DoP, Building Control cannot approve the structural frame.
5. Material Certificates
Mill certificates (EN 10204 Type 3.1) for all structural steel, confirming steel grade, chemical composition, mechanical properties, and heat/cast number for traceability.
6. Electrical Design Certificate
For the PV electrical installation: system schematic, cable sizing calculations, protection coordination, earthing design, BS 7671 (IET Wiring Regulations, 18th Edition) compliance certificate, and G99 application confirmation for grid-connected systems over 3.68 kW per phase.
7. Site Investigation Report (if required)
For pad or piled foundations, Building Control may require a site investigation report confirming soil type and bearing capacity, groundwater level, contamination status, and existing underground services. For standard commercial sites, a desktop study referencing BGS (British Geological Survey) data may be sufficient.
Common Reasons for Building Control Rejection
Incomplete Structural Calculations
The most common reason. Calculations must be complete and signed by a qualified engineer. Missing load cases (particularly wind uplift on canopy structures) will result in a query or rejection.
Missing EN 1090-1 Documentation
Submitting structural steelwork without a valid Declaration of Performance and FPC certificate is a regulatory failure. Building Control is obligated to reject non-compliant structural products.
Inadequate Foundation Design
Assuming foundation sizes without reference to actual or assumed ground conditions. Foundation design must be justified by either a site investigation or conservative assumed bearing pressures (typically 50–100 kN/m² under BS EN 1997-1).
Drainage Not Addressed
If the carport is above a permeable surface, the Building Regulations (and Class OA conditions) require surface water management. A simple drainage statement is usually sufficient.
Electrical Installation Not Notified
PV installations must be notified to Building Control under Part P. If your electrician is registered with a competent person scheme (NICEIC, NAPIT), they can self-certify. Otherwise, a Building Control inspection is required.
The Approval Process: Step by Step
1. Pre-submission consultation — Contact your Building Control body to discuss the project scope and confirm documentation requirements.
2. Submit Full Plans application — Submit all documentation listed above with the application form.
3. Plan check (2–5 weeks) — Building Control reviews and issues approval, conditional approval, or queries.
4. Commencement notice — Give Building Control at least 2 working days' notice before starting work.
5. Site inspections — Foundation excavation, steel erection, and completion.
6. Completion certificate — Legal confirmation that the works comply with the Building Regulations.
How KLY Solar Simplifies Building Control
When you order a solar carport frame kit from KLY Solar, the full Building Control documentation package is included: structural calculations by a chartered structural engineer, general arrangement drawings, fabrication drawings, EN 1090-1 Declaration of Performance (CE/UKCA marked, EXC2), material certificates (EN 10204 Type 3.1), foundation design (for standard ground conditions), and installation guide.
Your EPC or installer provides the electrical design, Part P notification, and manages the Building Control application. We provide the structural documentation they need to make that submission complete.
Ready to specify a solar carport for your next project? View our solar carport systems or contact us for documentation requirements.
About the Author
Keith Lin is the Director of KLY Solar (KLY Global Ltd), a UK supplier of solar carport structure kits for commercial project teams.
Sources cited in this article:
KLY GLOBAL LTD trading as KLY Solar | Company No. 14169672
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