When does commercial solar require planning permission?

Commercial solar requires planning permission whenever the install falls outside the conditions of Permitted Development under Class A Part 14 GPDO 2015. The most common triggers are: a listed building, a property in a conservation area (where the panels are visible from a public highway), a scheduled monument or World Heritage Site, ground-mounted arrays above 9 m², any roof-mount system that protrudes more than 200 mm above the existing roof plane, and any property where the local council has issued an Article 4 Direction removing PD rights for that street or area. The full planning application process takes 8-13 weeks and costs £462 (commercial under 5,000 m²) or higher for larger developments.

How the planning application process works

If you need planning permission, the process is:

1. Pre-application enquiry (optional but recommended): submit your design intent to the council’s planning team. £100-£500 fee depending on council. Gets you written feedback on likely outcome before formal submission. Saves rework.
2. Prepare application documents: site plans (1:500 location, 1:200 site layout), elevations showing panels, design and access statement (D&A), heritage statement if listed/CA, structural calcs, ecological survey if relevant.
3. Submit via Planning Portal: planningportal.co.uk. Pay fee (£462 for most commercial PV in 2026).
4. Validation: council checks application is complete. Up to 21 days.
5. Determination: 8 weeks for minor applications, 13 weeks for major. Public consultation runs 21 days during this window.
6. Decision: granted, granted with conditions, or refused. Refusal can be appealed to Planning Inspectorate.

Most commercial solar applications, even in conservation areas, succeed on first submission if professionally prepared. Refusal rates for SME PV are below 5% nationally.

Documents you’ll need to submit

Document	Purpose
Site location plan (1:1250 or 1:2500)	Show property in wider context
Block plan (1:500)	Show building footprint and PV layout
Existing and proposed elevations	Visual of building with/without panels
Roof plan with panel layout	Detail of array configuration
Design and Access Statement	Justify the design choices
Heritage Statement (if listed/CA)	Demonstrate impact on heritage asset
Structural calculations	Roof can take added weight
Glint and glare assessment (rare, but if near airport/major road)	Show no traffic safety impact

Conservation area applications

The most common case where commercial solar needs planning. Key principles:

• Front-facing roofs (visible from public highway) trigger planning
• Rear-facing roofs often remain PD even in CA
• Panels must be sympathetic colour (matt black, anti-reflective)
• Mounting hardware must not be highly visible
• Heritage Statement must address character, appearance, setting

Success rates: high for rear-roof installs, moderate for side-roof, lower for front-facing on streets with strong heritage character.

Listed buildings

Listed buildings need both planning permission AND Listed Building Consent (LBC). Always.

• Grade II: most numerous, most flexible. Solar often achievable on outbuildings or rear roofs.
• Grade II*: tighter scrutiny. Solar often refused unless invisible.
• Grade I: highest sensitivity. Solar approval rare unless specifically designed (slim-line, like Solarcentury C21e tiles).

The council conservation officer is the key decision-maker. Pre-application meetings essential.

Article 4 Directions

Local councils can remove specific PD rights from defined areas. Reasons vary:

• Specific market town centres
• Streetscape preservation in suburbs
• Unique architectural character zones
• Areas of Outstanding Natural Beauty (AONB) sometimes have additional restrictions

Check before assuming PD applies. Search “[your council] Article 4 Direction” or call the planning department.

Worked example: 80 kW system on a 19th-century mill, conservation area

Building: unlisted but in conservation area. Front roof visible from main road; rear roof not.

Installer proposed split design: 30 kW on front roof, 50 kW on rear. Front needed planning; rear was PD.

Decision: separate the install. Submit planning for the 30 kW front-facing portion. Install the rear under PD without application. Result: 50 kW commissioned in 12 weeks; front 30 kW gained planning at week 13, commissioned week 18.

Common misconceptions about solar planning

“Pre-application advice doesn’t matter” — wrong. Pre-app feedback dramatically improves first-time approval. Worth £100-£500 fee.

“Planning takes 6 months” — that’s the worst case. 8-13 weeks is normal.

“Refusal kills the project” — no. Most refusals are reversed on appeal or revised resubmission.

“You can hide solar from the conservation officer” — extremely bad idea. Council enforcement teams routinely review aerial imagery and respond to public reports. Removal orders are expensive.

Next steps

For a planning-aware feasibility study, contact us. See planning rules overview, listed buildings, and building regulations. For our grants page and cost guide, follow the links.