Competent Person Schemes: FENSA, NICEIC, NAPIT Explained

‍‌‌​‌‌‌‌‌‌‌‌‌​​​‌‌‌​​​​​‌​‌​‌​​‌‌‍For small builders and main contractors (England)

Last reviewed: March 2026

This is the self-cert route. A Competent Person Scheme (CPS) lets a registered installer certify that certain work meets Building Regs without you filing a Building Control application for that bit. They notify the work centrally, BC get told, and the homeowner gets a certificate. It doesn't make the work optional - it just changes who signs it off and how.

Big picture

• If a CPS installer does the job and actually notifies it, you don't need a separate BC application for that element.
• If a non-registered mate does it, or the registered guy forgets to notify, it's back on you and Building Control.
• Being "on a scheme" is not a magic shield - you still have to follow the regs, manufacturer instructions and any site-specific design.

Main schemes - what they cover

(England, domestic focus. There are others, but these are the ones that actually come up on site.)

Gas Safe Register

• What it mainly covers: Gas appliances and pipework
• Parts it touches: Part J, knock-ons into L and G
• What you can self-certify: Installation/alteration of gas boilers, fires, hobs, pipework and flues in dwellings. Installer notifies Gas Safe, certificate goes to owner, BC informed.
• What still needs BC / others: Anything structural (flues through roofs/walls that need structural changes), new openings, and most non-gas works around the install still need BC.
• Common gotchas: Being Gas Safe doesn't cover electrics, chimneys or building work. If they don't submit the notification, there's no Building Regs evidence.

NICEIC / NAPIT / ELECSA etc. (Part P electrical CPS)

• What it mainly covers: Domestic electrical work
• Parts it touches: Part P, knock-ons into other Parts
• What you can self-certify: New circuits, consumer unit changes, rewires, certain alterations in dwellings. They test, certify and notify; owner gets Part P cert.
• What still needs BC / others: Structural, fire, access and other regs still apply. Big refurb jobs still need BC even if the electrics are via CPS.
• Common gotchas: Loads of sparks do the work but don't notify. No notification = no proof of compliance when surveyors/solicitors ask.

FENSA

• What it mainly covers: Replacement windows and doors in dwellings
• Parts it touches: Part L, F, K, B, and Q on new dwellings
• What you can self-certify: Like-for-like window/door replacements in existing homes. They fit, self-certify and notify BC via the scheme.
• What still needs BC / others: New openings, major structural changes, new builds and many conversions still go through BC. Security (Part Q) only on new dwellings, not all FENSA jobs.
• Common gotchas: Homeowners often think "FENSA = everything is compliant forever". If you're doing structural/window layout changes, BC still care.

CERTASS / other window CPS

• What it mainly covers: Replacement glazing and sometimes new installs
• Parts it touches: Same as FENSA: L, F, K, B, Q where applicable
• What you can self-certify: Similar to FENSA - replacement windows/doors to dwellings, self-certified and notified by the installer.
• What still needs BC / others: New openings, structure, and non-standard work need BC. In blocks or mixed-use, extra fire/security rules may go beyond scheme scope.
• Common gotchas: Builders assume "any window guy" is in a scheme. Many aren't - check before you skip BC.

HETAS

• What it mainly covers: Solid fuel and biomass appliances
• Parts it touches: Part J, plus CO alarms (J3), B & L knock-ons
• What you can self-certify: Wood burners, multi-fuel stoves, some biomass boilers and flues. HETAS can self-certify the appliance and flue for Building Regs.
• What still needs BC / others: Structural work, chimneys, hearth construction beyond the appliance/flue spec, and non-solid-fuel appliances still need BC or other schemes.
• Common gotchas: Clients think any stove fitter is HETAS. If they aren't, you either involve BC or you've got an un-certified stove.

OFTEC

• What it mainly covers: Oil-fired heating appliances and oil tanks
• Parts it touches: Part J, plus H for oil storage, L/G knock-ons
• What you can self-certify: Oil boilers, some storage tanks and associated pipework. OFTEC can self-certify the installation for Building Regs.
• What still needs BC / others: Structural changes, flue/chimney alterations beyond their scope, and drainage/pollution protection can still need BC input.
• Common gotchas: Oil tank siting and fire separation can go beyond the CPS tick-box - don't let "I'm OFTEC" override drawings or BC conditions.

Benchmark (not a CPS but commonly seen)

• What it mainly covers: Commissioning of boilers/heating systems
• Parts it touches: Supports Part L & G compliance
• What you can self-certify: Benchmark is a commissioning checklist scheme used by boiler manufacturers. Filled-in Benchmark book helps show the system's been commissioned properly.
• What still needs BC / others: Benchmark alone is not Building Regs notification - you still need Gas Safe/OFTEC and/or BC in the loop.
• Common gotchas: Builders wave a Benchmark book as if it's a completion cert. It isn't. It's just proof you (hopefully) commissioned properly.

APHC / other plumbing schemes

• What it mainly covers: Plumbing/heating work, sometimes CPS elements
• Parts it touches: Mainly G (water/hot water) with cross-over
• What you can self-certify: Certain plumbing/heating installations can be self-certified under recognised schemes, depending on scope.
• What still needs BC / others: Anything structural, drainage outside their remit, or energy controls still fall to BC/Part H/L.
• Common gotchas: Variation between schemes - don't assume every APHC member can self-certify every type of plumbing job. Check.

MCS + CPS (via NICEIC/NAPIT etc.)

• What it mainly covers: Renewables (PV, heat pumps, solar thermal)
• Parts it touches: Part L, J, sometimes F, and S by knock-on
• What you can self-certify: Design, install and self-certify some renewables/low-carbon systems, often needed for grants.
• What still needs BC / others: Structural work, broader compliance, and non-covered elements still need BC.
• Common gotchas: PV/heat pump installers may handle their bit, but your roof structure, insulation and wiring routes are still on you.

"I'm registered" vs "I've actually notified"

Big difference:

• Registered means they're on the scheme's books and can self-certify.
• Notified means they actually submitted that specific job to the scheme and a certificate went to BC/owner.

If your subcontractor:

• Fits the boiler/windows/rewire,
• Hands the client a "we'll send the cert",
• Then never notifies,

You effectively still have un-notified work in the eyes of solicitors and surveyors. The owner ends up chasing regularisation or retrospective certificates later.

As main contractor, best practice

• Ask for job-specific certificates (Gas Safe, Part P, FENSA, HETAS, etc.) before you final-invoice.
• Keep copies in your own job file - you'll be asked for them when there's a problem years later.

If someone who isn't registered does the work

If a non-CPS person does CPS-type work (e.g. gas, rewire, windows, stove):

• The work still requires Building Regs sign-off.
• The only legitimate route then is through Building Control (full or building notice) with appropriate testing and evidence.

That means:

• Extra fees.
• More inspections.
• Possibly opening up finished work so BC can see it and/or an independent test (e.g. EICR, flue tests) to prove compliance.

So no, "my mate's handy" doesn't solve anything - it just moves the problem onto BC and the client.

Main contractor: have you actually checked?

Your risk isn't just "did someone fit it?" - it's "can the owner prove it was done right?" later.

Basic checks you should bake in

• For gas: check the Gas Safe ID and look up their business/engineer on the Gas Safe register.
• For electrics: check NICEIC / NAPIT / ELECSA registration via their online search.
• For windows: confirm FENSA / CERTASS registration and that they can issue certs in the job's postcode.
• For stoves: check HETAS registration.
• For oil: check OFTEC registration.

If they won't give you their company name and registration number, you've got your answer.

And again: registration alone isn't enough. You need the actual certificate for the job at the end.

How to verify someone quickly

You don't need URLs printed - just know what to search:

• Search "[Scheme name] register" and use their official "find an installer/engineer/business" tool.
• Check:
  • The business name matches the van/invoice.
  • The engineer is currently registered and approved for the type of work (domestic, gas type, etc.).
  • The postcode area isn't excluded.

Do this once when you first work with someone. After that, just chase certs per job.

Bottom line: Competent Person Schemes are there to save you time with BC, not to dodge Building Regs. Use them properly, collect the certs, and you'll have far fewer nasty conversations with surveyors and solicitors down the line.

This page is a general guide for small builders and main contractors working on dwellings in England. It doesn't cover every scheme or non-domestic work. Always check the latest scheme rules, Approved Documents, your drawings/spec, planning conditions and Building Control before you start cutting or pouring. SiteKiln does not provide legal, financial or tax advice. All content is for general information purposes only. Always seek professional advice for your specific situation.

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