2.2 Building Regulations and Planning Permission

2.2 Building Regulations and Planning Permission

Quick Answer: A lawful PV installation can still fail Building Regulations, and a structurally sound array can still need planning consent. In England and Wales the Building Regulations 2010 bite through Part A (structure), Part B (fire), Part C (moisture), Part L (conservation of fuel and power), and Part P (electrical safety in dwellings). Scotland uses The Building (Scotland) Regulations 2004 and Technical Handbooks. Northern Ireland uses The Building Regulations (Northern Ireland) 2012 and Technical Booklets. Many domestic rooftop arrays are permitted development subject to limits, but planning is jurisdiction- and site-specific. There is no single UK-wide permitted-development kilowatt size you can memorise for 2922-34. MCS contractors must tell customers which permissions apply and who notifies Building Regulations.

This independent OpenExamPrep section is a study resource for City & Guilds 2922-34. Building control and planning are not the same as ESQCR/G98 paperwork from the previous section. You can notify a DNO correctly and still leave a leaking roof, an overloaded rafter, or an unnotified electrical alteration. Learning Outcome 1 expects you to know which regulatory family you are in before you start stripping tiles.

Building Regulations set minimum standards for building work. Planning permission is about whether development is acceptable in planning terms. MCS is a microgeneration installer scheme used for many consumer-facing quality and incentive routes; completing 2922-34 does not by itself make you an MCS contractor, and MCS paperwork does not automatically discharge building control. Keep those three stacks separate when a customer says “you’re certified, so we don’t need the council.”

England and Wales: Building Regulations 2010

Part A — Structure

Part A is about the building remaining stable. PV modules, mounting rails, in-roof cassettes, and ballast add dead load. Wind tries to peel the array off the roof as uplift. Snow and access loads still exist under the array. You therefore design the roof interface, not just the kilowatt-peak.

Mechanical fix through the covering into rafters or into a designed roofing kit is the usual pitched-roof route. Ballast appears more often on flat roofs, where you resist uplift with weight instead of (or as well as) penetrations. Ballast is not a free pass: the roof deck and structure must carry the extra mass, and wind can still slide or overturn poorly arranged trays. If you cannot show that the existing roof can take the loads, you stop and get structural input. “The tiles seemed fine” is not a Part A argument.

Part B — Fire safety

Part B is about fire spread and the roof as a fire-resisting covering. Adding an on-roof or in-roof array changes the roof build-up. In-roof kits replace tiles or slates over part of the slope; the kit and the remaining covering must still present an acceptable roof covering classification for the building. Using an MCS 012 certified pitched-roof installation kit is the common evidence path for the roof-interface product. Where the kit is not MCS 012, you should expect to need extra evidence, including a fire risk assessment of that roof interface, rather than assuming the modules themselves are a fire certificate.

Fire thinking also includes inverter and battery location, cable routes through fire-separating construction, and not blocking escape. Those issues overlap later with PAS 63100 for dwelling batteries, but Part B is the Building Regulations hook for the roof and the dwelling as a building.

Part C — Site preparation and resistance to contaminants and moisture

Part C is the weathertightness statute-family for this job. Solar PV fails Part C when water follows a poorly flashed rail, a notched tile with no soaker, a cable penetration without a proprietary gland, or an in-roof cassette that does not lap the remaining covering. Notching and cutting tiles is not banned; doing it so that capillary paths open into the batten space is. Condensation and trapped moisture under an on-roof array can also damage the covering. The method statement should name flashing details, hook positions relative to rafters, and how you restore the covering when you leave.

Part L — Conservation of fuel and power

Part L is easy to skip because PV generates energy. The regulation still says you must not worsen fabric performance. In-roof systems replace part of the weatherproof, and sometimes insulating, layer. Crushing mineral wool, leaving uninsulated strips, or breaking airtightness around cable entries can increase heat loss even while the inverter reports kilowatt-hours. On-roof systems can still create thermal bridges at fixings if you destroy insulation to chase timber. Design the roof build-up so the dwelling is not colder in February because you wanted a tidy DC run.

Part P — Electrical safety in dwellings

Part P covers electrical safety in dwellings in this England and Wales set. Much electrical installation work in dwellings is notifiable. A typical PV and hybrid installation in a house is not “like-for-like accessory replacement.” Notification is made either through a Competent Persons Scheme member who self-certifies, or by giving notice to building control before the work (and following their inspection route). You do not get to decide that a loft inverter is “not really Part P” because DC lives on the roof.

If you are not a scheme member for that work, building control is not optional extras. If you are a scheme member, the customer still needs to understand that the certificate they receive is the building-regulations route, not a magic MCS sticker. Wales uses the same 2010 Regulations family in this handbook topic; always confirm the current Approved Document and any Welsh differences on a live job rather than inventing a second Part P.

Scotland and Northern Ireland

Scotland does not use Approved Document P as its statute. The Building (Scotland) Regulations 2004 and the Technical Handbooks (Domestic and Non-Domestic) are the building-standards route, administered with a verifier (usually the local authority). Some work needs a building warrant; some work is exempt or follows a different notification path. Do not tell a customer in Glasgow that you will “Part P it through NICEIC the English way” without checking the Scottish procedure for that building.

Northern Ireland uses The Building Regulations (Northern Ireland) 2012 and Technical Booklets, with district-council building control. Again, the headings look familiar (structure, fire, moisture, conservation of fuel and power, electrical installations) but the documents and notification mechanics are not a copy-paste of England. 2922-34 is a UK-wide knowledge award in practice: name the correct national instrument instead of inventing a single “UK Building Regulations 2010” that does not exist for Scotland or Northern Ireland.

Planning permission and permitted development

The Planning Portal’s England guidance is the right tone for this exam: installation of solar panels on residential buildings may be permitted development, with no planning application, if limits and conditions are met. You should discuss with the local planning authority whether those limits will be met. Guidance for England is not automatically the rule in Wales, Scotland, or Northern Ireland. GOV.UK points people to the relevant nation’s planning pages and to the local planning authority.

Typical conditions you must check, without turning them into a fake UK-wide kilowatt cap, include:

• Listed buildings — listed building consent is a separate heritage control; rooftop PV is not “just PD” on a listed dwelling.
• Conservation areas, world heritage sites, and similar designations — extra limits often apply, especially on principal elevations or wall-mounted arrays.
• Protrusion and appearance — PD rights usually constrain how far panels stand off the roof plane and how they sit relative to the ridge and eaves.
• Article 4 directions and local rules that remove or tighten PD.
• Ground-mount, outbuildings, and non-domestic buildings — different classes, often tighter than a simple house roof.

Do not memorise a single nationwide “under X kW is always permitted development.” Capacity is the wrong proxy anyway: planning looks at the building and the place, while G98 looks at amperes. A 3 kW array on a listed cottage can need consent; a larger array on an ordinary estate house might be PD if the local conditions are met.

Who tells the customer, and who notifies

MCS installer-scheme contractors must tell the customer which permissions apply and who notifies Building Regulations. That conversation belongs in the quotation, not in a handover folder after the scaffolding has gone. Spell out, in plain language:

• whether you have checked planning (PD, application, or heritage consent);
• whether building work is notifiable, and whether you will self-certify through a Competent Persons Scheme (England and Wales dwellings) or use local building control / Scottish verifier routes;
• that DNO G98/G99 notification is a network duty, not a substitute for planning or building control.

In practice: An in-roof array on a 1930s semi in England needs Part A (rafter loads and wind), Part B (in-roof kit fire path — MCS 012 or extra fire evidence), Part C (flashings and tile interfaces), Part L (do not gut the loft insulation), and Part P (notifiable electrical work). Planning may be PD if the local limits are met. The same kit on a listed farmhouse in a conservation area can need listed building consent even if the electrical design is identical. Scotland would be described using the 2004 Regulations and Technical Handbooks, not Part P.

Official sources

• Planning Portal: solar panels — England PD may apply subject to limits; check the local planning authority; Wales may differ.
• GOV.UK: when you need planning permission — contact the local planning authority; separate links for Scotland, Wales, and Northern Ireland.
• Permitted development rights for householders: technical guidance — England householder PD technical guide.
• Building Regulations 2010 Approved Documents A, B, C, L, and P (England), plus the Welsh Approved Documents where you work in Wales.
• Scottish Technical Handbooks and Northern Ireland Technical Booklets for those nations.

Check the current local authority and Approved Document pages before you start work. This study resource maps the 2922-34 Learning Outcome 1 topics; it is not a substitute for the building-control application on a named site.