To choose a steel fabricator in the UK, start with your project's EN 1090 execution class. Then check each fabricator holds BS EN 1090-1 certification scoped to that class. Confirm their CE or UKCA marking, capacity and finishing. This turns a same-looking shortlist into a clear, risk-based decision.

Most fabricators look identical on paper. Same logos, same claims, same accreditation badges. The difference that protects your project is one most buyers never check: the certified execution class. This guide gives you a seven-step framework and the exact questions to ask.

What does a steel fabricator do?

A steel fabricator is a company that cuts, drills, welds and assembles structural steel into finished components. These include beams, columns and frames, ready for erection on site. A steel supplier only sells raw sections. In the UK, structural steel fabricators must be certified to BS EN 1090-1.

Fabrication and supply are different jobs. A fabricator transforms raw steel into a structure. A stockholder or supplier only sells the raw material. A steel erector then installs the finished steel on site.

Role	What they do	EN 1090 applies?
Steel fabricator	Cuts, drills, welds and assembles steel into finished structural components	Yes
Steel supplier / stockholder	Sells raw steel sections and plate	No
Steel erector	Installs and bolts fabricated steel on site	Not for fabrication

BS EN 1090 is the standard that governs structural steel and aluminium fabrication in the UK and Europe. Knowing which role you are buying keeps your comparison fair. The rest of this framework focuses on the fabricator.

Step 1: Confirm what you need fabricated

Before you compare fabricators, define your project scope. Note the structure type, steel grade, tonnage and connection complexity. Add your finishing needs, such as galvanising or fire protection, and your programme dates. This scope sets your execution class. Your execution class decides which fabricators can even quote.

Work through a short scope checklist first.

Structure type: frame, mezzanine, bridge or marine structure
Steel grade and section sizes
Total tonnage
Connection type and complexity
Finishing: galvanising, intumescent or protective coating
Delivery and erection dates

Get this down before you call anyone. A clear scope stops you comparing quotes that cover different work.

Step 2: Which execution class does your project need?

An execution class (EXC) is the level of quality and inspection control a structure needs under BS EN 1090-2. The classes run from EXC1, the lowest, to EXC4, the highest. Most standard buildings fall under EXC2. Bridges, stadia and safety-critical structures usually need EXC3 or EXC4.

Your execution class is set by three factors. BS EN 1090-2 combines them in a matrix in Annex B.

Consequence class (CC1 to CC3): how serious a failure would be
Service category (SC1 to SC2): static loading, or fatigue and dynamic loading
Production category (PC1 to PC2): how complex the fabrication is

The designer or specifying engineer sets the class. That person may be you.

Execution class	Typical structures	Control level
EXC1	Low-consequence structures, such as some single-storey agricultural buildings	Lowest
EXC2	Most standard building frames: commercial, industrial and residential	Standard (default)
EXC3	Bridges, stadia, crane-supporting and fatigue-loaded structures	High
EXC4	Special structures where failure has extreme consequences	Highest

Where no class is specified, Clause 4.1.2 of BS EN 1090-2 applies EXC2 by default. Most UK buildings sit at EXC2. The class matters for one practical reason. A fabricator can only work up to the class they are certified for.

Step 3: Check EN 1090 certification and its execution-class scope

A UK structural steel fabricator must hold BS EN 1090-1 certification with Factory Production Control. That certificate is scoped to a maximum execution class. A fabricator certified only to EXC2 cannot legally fabricate EXC3 or EXC4 work. Always confirm their certified class covers your project's class.

BS EN 1090-1 is the standard for factory production control and CE or UKCA marking of fabricated steel. Certification is issued by an approved body and states a maximum execution class. You can read more in our EN 1090 certification guidance.

Factory Production Control (FPC) is a documented quality system that keeps fabrication consistent.

Scope is the point most buyers miss. Certification to EXC4 covers EXC1 to EXC4. Certification to EXC2 covers EXC1 and EXC2 only. A fabricator cannot simply accept higher-class work. They must extend their procedures and have the higher class confirmed by their certification body first.

“An EN 1090 certificate is scoped to a maximum execution class. Appointing a fabricator certified below your project's class is the most common and costly compliance error we see.”

Other checks add confidence but do not replace EN 1090. Look for ISO 9001 for quality management. Look for Constructionline or CHAS for pre-qualification. None of these substitute for EN 1090-1 on structural steel.

Step 4: Confirm CE or UKCA marking and verify the certificate

Fabricated structural steelwork sold in Great Britain must carry a UKCA or CE mark under BS EN 1090-1. A Declaration of Performance supports the mark. Since September 2024, CE marking is recognised indefinitely in Great Britain, alongside UKCA. Check the fabricator's certificate names the body, execution class and Factory Production Control.

CE marking became mandatory for fabricated structural steelwork across the EU on 1 July 2014, according to SteelConstruction.info. The UK later introduced UKCA marking as its own equivalent.

The deadline picture has changed. The UK government once planned to end CE recognition on 30 June 2025. In the government's September 2024 statement, it confirmed CE marking will be recognised indefinitely for construction products in Great Britain. UKCA remains valid too. Any future change carries a minimum two-year transition.

Verify a certificate in four steps.

Ask for the BS EN 1090-1 certificate, not just a website logo.
Check the named certification body and that it is UKAS-accredited.
Confirm the certified execution class covers your project.
Confirm Factory Production Control is included.

Northern Ireland differs. Products placed there need a CE mark, sometimes with a UKNI mark alongside it.

Step 5: Assess capacity, capabilities and finishing

Check the fabricator can deliver your tonnage on time. Look at workshop capacity, plant and the steel grades they handle. Then check finishing. Keeping fabrication and finishing on one site removes a transport and handling step. That single-site workflow cuts delay and reduces the risk of damage or defects.

Match capacity to your programme. Ask about current workload and realistic start dates. Ask which steel grades and section sizes they handle.

Finishing changes your risk. Galvanising is a zinc coating that protects steel from corrosion. Intumescent coating provides fire protection. A fabricator with in-house galvanising controls the whole process under one roof.

Ask a simple question. What is done in-house, and what is subcontracted? More in-house work means fewer handovers and fewer points of failure.

Step 6: Judge track record, lead times and quality evidence

Judge a fabricator on evidence, not claims. Ask for comparable completed projects and references from main contractors. Compare their typical lead times against your programme. Ask for quality records, such as inspection and test plans or weld inspection reports. A long trading history points to reliable delivery.

References tell you more than a brochure. Ask to speak to a main contractor who used them recently. Ask about their recent projects and what they were like on programme and on defects.

Documentation shows control. An inspection and test plan (ITP) records what gets checked and when. Non-destructive testing (NDT) reports show weld quality. Traceability records link steel back to its source.

Trading history is a useful signal. A fabricator with many years of work and repeat clients has survived real projects.

Step 7: Compare quotes and spot the red flags

Compare quotes on matched scope, not headline price. Line up execution class, finishing, delivery and erection across every quote. The cheapest number often covers less work. Watch for red flags. These include no verifiable certificate, a certified class below your project, vague finishing, or a price far under the field.

Normalise every quote before you compare. Put each on the same scope, execution class and finishing. Only then does price mean anything.

Common red flags include the following.

No EN 1090-1 certificate you can verify
A certified execution class below your project's
No clear Declaration of Performance
Vague answers on what is subcontracted
A price far below every other quote

The lowest quote is rarely the cheapest outcome. Rework, delay and non-compliance cost far more than the gap on day one.

Frequently asked questions

What certifications should a UK steel fabricator have?

A UK structural steel fabricator should hold BS EN 1090-1 certification with Factory Production Control. That certification should be scoped to your project's execution class. It should also apply CE or UKCA marking. Accreditations like ISO 9001 and Constructionline help with pre-qualification. They do not replace EN 1090 for structural steelwork.

What is EN 1090 certification?

EN 1090 is the standard for fabricating structural steel and aluminium. BS EN 1090-1 covers conformity assessment and CE or UKCA marking. BS EN 1090-2 sets the technical rules by execution class, from EXC1 to EXC4. A certified fabricator has proven Factory Production Control to a certification body.

Do steel fabricators need to be CE or UKCA marked?

Yes. Fabricated structural steelwork placed on the Great Britain market must carry a UKCA or CE mark under BS EN 1090-1. A Declaration of Performance supports the mark. As of September 2024, CE marking is recognised indefinitely in Great Britain, so either mark is currently acceptable.

Does a fabricator's execution class need to match my project?

Yes. A BS EN 1090-1 certificate is scoped to a maximum execution class. A fabricator certified only to EXC2 cannot legally fabricate EXC3 or EXC4 work. To take higher-class work, they must extend their scope and be re-certified. Always confirm their class covers yours.

What questions should I ask a steel fabricator before hiring?

Ask for their BS EN 1090-1 certificate and its certified execution class. Ask whether finishing, such as galvanising, is done in-house. Ask about lead times against your programme and for comparable project references. Ask how they handle quality records and traceability. Then verify the certificate yourself.

The bottom line

Choosing a steel fabricator comes down to matching, not price. Set your execution class, then appoint a fabricator certified to cover it, with the capacity and finishing your project needs. Get those right and the rest of the decision becomes simple.

Not sure which execution class your project needs? That is the first thing to pin down. European Active Projects Limited fabricates structural steel to EXC4, the highest execution class, with in-house galvanising at its Southampton facility. On one recent project, the team supplied 47 beams to south-west London in three days with zero defects. Talk to the team about your structural steel fabrication requirements, from marine and industrial steelwork upward.