Fabricate Aluminium Shopfronts In-House, or Buy Supply-Only?
For most installers, shopfitters and glazing companies, buying frames fabricated supply-only is cheaper than fabricating in-house — a one-fabricator workshop carries saw, crimper, router, jigs, extraction, premises, wages, software and first-year scrap on its own output, costs a trade fabricator spreads across hundreds of frames a year. Above a sustained weekly volume, fed by your own installation pipeline, in-house can pay back. Here is the maths either way.
By Stephen Chappell, Managing Director, Kingsland Fabrications. Updated 3 July 2026. Trade-only — we supply and fabricate; we don't install.
The short answer: it comes down to sustained volume
Is it cheaper to fabricate aluminium frames in-house or buy them in fabricated? For most installation businesses, buying fabricated wins. Not because fabrication is difficult to learn — because the fixed costs of a fabrication line only make sense divided across a high, steady frame count. Every machine, wage, software licence and mis-cut bar becomes a cost per frame, and at low volume the overhead on each frame outweighs the fabrication margin you hoped to keep.
A declaration of interest: Kingsland Fabrications is a supply-only trade fabricator, so we earn when you buy frames in. That is exactly why this guide is honest about the cases where in-house wins anyway — the maths is checkable, and there are businesses on both sides of the line.
The break-even comparison further down shows how each cost line behaves at two, five and ten frames a week. If your true year-round volume sits at the top end, with your own installation pipeline to absorb it, in-house deserves a serious look — and we say so below. If not, the rest of this page shows where the money goes, written from a supply-only fabricator's own workshop floor.
What machinery do you need to fabricate aluminium shopfronts?
A minimum credible shopfront line needs six things before the first frame is assembled. UK commercial aluminium is mechanically joined — cut, machined, cleated and crimped, not welded — so the list is specific:
Double-mitre saw
The workhorse: it cuts both mitred ends of a bar to length and angle in one setup, and everything downstream depends on its accuracy. New machines from the established brands are a serious capital purchase on their own.
Corner crimping press
UK commercial aluminium frames are joined over internal cleats, with the profile crimped mechanically around them — not welded. The crimper turns four cut bars into a rigid, square corner; there is no shopfront line without one.
Copy router or CNC machining centre
Lock cases, hinge preps, spindle holes, drainage slots. A copy router is the manual entry point; a CNC machining centre automates the machining — and can cost more than the rest of the workshop combined.
End miller
Preps transom and mullion ends so T-joints sit flush against the mating profile. Easy to forget on the shopping list, impossible to miss in the finished frame.
Assembly benches and jigs
Squareness is made on the jig table, not the saw. A frame can be in tolerance on every cut and still rack out of square if assembled unchecked — the cheapest kit on this list, and the most important.
Extraction, air and handling
Swarf extraction, compressed air for tooling, and racking to store and move profile bars over six metres long. None of it cuts metal; all of it is mandatory.
The machinery names you will meet first are Elumatec and Haffner — the brands most UK aluminium shops run and the used market trades in. We run Elumatec CNC machinery ourselves, engineered from LogiKal, so this list comes from experience rather than a brochure.
Second-hand kit takes real money off the outlay, but calibration, tooling and support risk transfers to you. A saw cutting half a degree out doesn't announce itself — it shows up weeks later as frames that won't sit square.
Even a used, minimum viable line — saw, crimper, router, jigs, extraction — is a five-figure outlay before a single bar is cut. A doorset-capable line with CNC machining runs well beyond that, and adds a certification burden the machinery list doesn't show.
The costs nobody itemises
The machinery list is the visible half of the budget. These six lines never appear on a machine invoice — and they are where most in-house plans quietly die.
- Premises. A fabrication line needs real floor area — machines, benches and racking for profile bars over six metres long — plus 3-phase power. Profile storage eats workshop space before you cut anything.
- Labour. Skilled aluminium fabricators are genuinely hard to hire, and the wage is a full-time commitment whether the saw is cutting or not. Lose your one fabricator and the line stops with them.
- A systems-house fabricator account. Systems houses supply profile through fabricator agreements — Jack Aluminium is the systems house whose profiles we fabricate; Smart Systems and Senior Architectural Systems are other names you'll meet. Accounts typically carry minimum purchase expectations, training and LogiKal-class software licences.
- Powder coating logistics. Buy mill-finish and every order adds a trip to the powder coater — transport, queue time and batch charges. Hold coated stock instead and working capital sits on a rack in colours a future order may never call for.
- Scrap and remakes. First-year remake rates are the hidden killer. A mis-cut on a six-metre bar is unrecoverable — the learning curve is paid in aluminium, exactly when each frame already carries the most overhead.
- Certification, if you make doorsets. PAS 24 testing, UKCA marking and factory production control audits are recurring commitments, not one-off purchases — and they arrive the moment doorsets join the product list.
The compliance terms above are unpacked in the performance standards section of our glossary.
Worked example: cost per frame, in-house vs supply-only
We are not going to print invented machinery prices or a fake per-frame rate — made-up figures are how comparisons like this mislead. What we can print is the structure, because it is the same for every business: divide every fixed cost of the line across your true annual frame count, add materials and scrap, and compare the result with a real supply-only trade quote. Here is how each cost line behaves at roughly 100, 250 and 500 frames a year.
| Cost line | ~2 frames a week | ~5 frames a week | ~10 frames a week |
|---|---|---|---|
| Machinery and premises amortisation | Dominant — the whole line carried by roughly 100 frames a year | Falling, but still a visible slice of every frame | Thin per frame across roughly 500 frames a year |
| Fabricator labour | A full-time wage for a part-time workload — idle hours land on every frame | Better utilised; holidays and sickness still stop the line | Fully utilised — and probably needs a second pair of hands |
| Profile, glass and hardware buying | Small orders at the top of the price list, with account minimums to hit | Mid-tier terms as volume becomes credible | Volume terms; stock turns fast enough to hold common colours |
| Scrap and remakes | Learning-curve remakes hit when each frame carries the most overhead | Falling as processes bed in | Low — if processes have matured |
| Verdict | Supply-only is almost always cheaper per frame | Marginal — the install pipeline and hiring market decide it | In-house can win, if the volume holds all year |
To rerun it with your own numbers you need five inputs: your real frame count over the last twelve months (not your best month annualised); the fully loaded machinery cost including tooling and training; a fabricator's total employment cost; an honest first-year scrap allowance; and real supply-only trade prices — from quotes, not guesses.
We can supply that last input directly: send a typical job spec through our quick quote form and we'll return a supply-only price within 24 hours, with CAD drawings, to plug into your comparison.
When in-house fabrication IS the right call
The section a fabricator's guide usually skips — here is where in-house genuinely wins:
Sustained volume with your own pipeline
If your installation teams consume frames every week of the year — not just in the best quarter — amortisation starts working for you, and the fabrication margin you were paying a supplier becomes yours.
Product-mix control
If your work leans on unusual preps, non-standard details or one-off specials, owning the workshop removes the translation loss between your surveyor and someone else's saw.
Same-day remake capability
For reactive work where an opening can't wait for even a rush turnaround, cutting and crimping a replacement the same afternoon is a service edge no external fabricator can match.
Strategic independence
No supplier lead time in your critical path, no exposure to someone else's order book. Some firms value that control above the per-frame maths — a legitimate call, made knowingly.
There is also a middle path: start with a saw and a jig bench for simple internal screens — forgiving tolerances, no certification burden — and keep buying doorsets in, because doorsets concentrate the hardware prep, machining and compliance load. You learn fabrication on the easy work without betting the business on the hard part.
The hybrid model most firms actually land on
Strip it back and the pattern most installation firms settle into is simple: keep the surveying and installation — where installer margin lives — and outsource the fabrication, where the capital and tolerance risk live. Supply-only trade fabrication exists precisely for that split.
The risk transfer is the under-priced part. Under supply-only, fabrication tolerance risk sits with the fabricator: every kit we build is jig-tested before dispatch, with a 99% first-time fit rate. In year one of an in-house line, the equivalent number is your remake rate — and you pay both sides of it, the scrapped bar and the lost fitting day.
Lead time works the same way. Our standard is 21 working days, quoted within 24 hours with CAD drawings, delivered palletised from the Warrington workshop throughout mainland Britain. An in-house queue is only as deep as your one fabricator — when they're on holiday, the lead time isn't three weeks, it's however long they're away.
"The installers who get this decision right count a full year's real volume, not their best month. A saw only earns its keep in the weeks it's cutting — and your fabricator takes holidays even when your order book doesn't."
— Stephen Chappell, Managing Director
In-house vs supply-only at a glance
| Factor | In-house fabrication | Supply-only fabricated |
|---|---|---|
| Up-front capital | Heavy — machinery, premises, software, profile stock | None — you pay per order |
| Cost per frame at low volume | High — fixed overhead concentrates on few frames | The trade price, and nothing else |
| Cost per frame at high sustained volume | Can undercut trade prices once kit and labour are fully utilised | Broadly flat as volume rises |
| Lead time control | Yours — including same-day remakes once you're fluent | The fabricator's — our standard is 21 working days, rush by arrangement |
| Certification burden (doorsets) | Yours — PAS 24 testing, UKCA marking, factory production control audits | Carried by the fabricator |
| Quality and tolerance risk | Yours — the learning curve is paid in remakes | The fabricator's — every kit we dispatch is jig-tested, with a 99% first-time fit rate |
| Scalability | Hire another fabricator, buy more kit | Send more orders |
| Cash flow | Capital tied up in machinery and bar stock | Pay per job as you invoice your own work |
The five-question checklist
- Weekly volume that holds across the whole year — count last year's actual frames, not the best month annualised.
- Your own installation pipeline to absorb the output, without chasing work to keep the saw busy.
- Capital that isn't better spent on surveyors, vans or winning more installation work.
- A local hiring market where skilled aluminium fabricators can actually be found.
- Appetite for compliance admin — PAS 24, UKCA and factory production control if doorsets are on the list.
Tick all five and it's worth pricing up a saw — genuinely. Miss two or more and buying fabricated protects your margin; the installation side is where your profit lives anyway.
Frequently asked questions
How much does it cost to set up in-house aluminium fabrication in the UK?
There is no honest single figure, but the shopping list is fixed: double-mitre saw, corner crimping press, copy router or CNC machining centre, end miller, jigs, extraction and compressed air — plus premises with 3-phase power, a skilled fabricator's wages, software and profile stock. Even a used minimum line is a five-figure outlay, and a CNC machining centre can cost more than the rest of the workshop combined. Price the full list against real supply-only trade quotes before deciding.
What volume of work justifies fabricating in-house?
Sustained volume held across the whole year, with your own installation pipeline to absorb the output. Divide the machinery amortisation, a fabricator's full employment cost and an honest scrap allowance across your true annual frame count, then compare with supply-only trade prices per frame. For installers doing a handful of frames a week, the overhead per frame usually outweighs the fabrication margin saved.
Can installers buy aluminium profile directly from the systems houses?
Generally only through a fabricator account, which typically carries minimum purchase expectations, training and software commitments. Systems houses — Jack Aluminium, Smart Systems, Senior Architectural Systems — supply full-length profile bars to fabricators, not cut parts to installers; small-quantity profile buying is rarely economic.
Can I buy cut kits and assemble the frames myself?
Some fabricators supply knock-down kits, but the squareness risk transfers to you: a kit can be in tolerance on every cut and still rack out of square when assembled without a jig. If you don't run a jig table, buy frames assembled and jig-tested.
What does 'supply-only fabricated' actually include?
A cut, machined, corner-joined frame assembled and checked square on a jig, with beads, gaskets and fixings included, a CAD drawing with the quote, and every item labelled to its opening reference and delivered palletised. You install it; the fabricator carries the fabrication tolerance risk.
Keep reading
Supply-Only Trade Fabrication
What supply-only means in practice, where our work ends and your fit begins, and why it keeps your margin clean.
Aluminium Shopfront Systems
The JD47 + JCW frontage kits we fabricate — frames, display zones, signage zones and entrance doors as one set.
Trade Aluminium Fabrication
How we work as a made-to-order trade fabricator for installers, contractors and glaziers.
Curtain Walling Cost Guide
The same honest cost logic applied to curtain walling — the anatomy, the variables and what moves a quote.
Weighing it up? Call 01925 500 295 or email sales@kingslandfabrications.co.uk — send your typical monthly volumes and we'll talk through honestly whether in-house or supply-only stacks up, even if the answer is a saw of your own. Got a live job? Send sizes and spec and we'll return a quote within 24 hours.