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Trade Double Glazing Manufacturer High Wycombe
Trade Sealed Unit Manufacturer · UK Made

Trade-grade sealed units. Built smarter.

A modern UK manufacturer of double, triple and specialist glass units — engineered to spec, delivered in days.

Get a quote → 020 8574 9342
20+ Product Types 3–5 Day Lead Trade Direct UK Made
12,400+ units shipped last quarter · UK Made
0.9 W/m²K U-value
5-yr warranty
3–5 day lead

Size it — instant spec

1200mm
1000mm
24kg / unit
0.9W/m²K
3–5day lead
Get exact price →
Integral Blinds

Integral blinds in your colours.

Venetian, pleated and motorised blinds permanently sealed between glass — child-safe, dust-free, maintenance-free.

View range → Get a quote
Low-energy thermal performance

Triple glazed. U-values to 0.5 W/m²K.

Dual Low-E coatings on surfaces 2 and 5. Argon or krypton fill. Warm edge spacer. Built for low-energy homes.

View triple glazed → Get a quote
Jumbo Capacity

Jumbo units up to 6000 × 3210mm.

The largest sealed unit capacity in southern England — oversized panels for commercial facades, shopfronts and statement glazing.

View jumbo units → Get a quote
Fire-Rated

Fire-rated glass. E30 to EI60.

Fire-resistant sealed units for commercial and residential specifications — integrity and insulation classes to EI60.

View fire-rated → Get a quote
20+Product types
6mMax jumbo
0.5Lowest U-value
FreeFactory collection
Glass sourced from
Pilkington UK Saint-Gobain FR Guardian US AGC JP Pyroguard SentryGlas® Pilkington UK Saint-Gobain FR Guardian US AGC JP Pyroguard SentryGlas®
20+
Product types in production
6m wide
Max jumbo unit size
0.5 W/m²K
Lowest U-value spec’d
3–5 days
Standard lead time
Range

Everything trade needs.

15 product types in production — from standard DGUs to specialist acoustic, fire-rated and walk-on glass.

View all products →
Two-pane double glazed sealed unit with spacer bar
Standard DGU28mm dual-sealedArgon-filled, Low-E. U-value 1.1 W/m²K. Industry standard.Triple GlazedU-values to 0.5Dual Low-E + dual gas fill. Passivhaus capable.
Jumbo glass sealed units for large glazed openings
Jumbo UnitsUp to 6m × 3.2mOversized units for shopfronts, picture windows and curtain walling.Integral BlindsFull colour rangeMotorised, magnetic, cordless. Sealed between glass.Fire-RatedE30 to EI60Pyrobel, Pyrostop, Pyroguard range.AcousticUp to Rw 54 dBAsymmetric panes + laminated. Road and aircraft noise.ToughenedHeat-treated to 620°C4× stronger than float. Safe-break to small pieces.LaminatedPVB / EVA interlayerHolds on break. Overhead glazing and balustrades.Smart GlassPDLC switchableClear ↔ frosted on demand. 230V trigger.Walk-on GlassFloors & rooflightsAnti-slip, load-rated, laminated construction.
Roof glazing and overhead sealed units with natural light
Roof GlazingOverhead & pitchedLaminated inner leaf, solar control coatings.Shaped UnitsArch, circle, triangleBespoke profiles cut to DXF. Any shape, same lead time.HeritageSlim-fit from 14mmPeriod properties. Listed building suitable.BalustradesJuliet & structuralToughened or laminated, edge-polished.Self-CleaningPilkington Activ™Photocatalytic + hydrophilic. Roof and hard-to-reach glass.
Spec finder

Not sure what you need? Answer 3 questions.

We’ll match you to the right unit type and link straight to a quote.

Step 1 of 3 · Application
What are you glazing?
Step 2 of 3 · Acoustics
Is noise reduction important?
Step 3 of 3 · Energy
Energy efficiency priority?
Recommended
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Not into quizzes? Browse the full comparison guide →

About CSU

Built for trade. Built in the UK.

CSU Ltd operates from a purpose-built High Wycombe facility — supplying glaziers, fabricators, contractors and commercial developers across the UK.

We source from Pilkington, Saint-Gobain, Guardian and AGC. Every unit ships argon-filled with warm edge spacer, dual-sealed for long-term gas retention.

Dual-seal IGU buildPolyisobutylene + silicone secondary, gas-tight
Up to 6000 × 3210mmLargest jumbo capacity in southern England
No minimum orderSingle units to full commercial projects, no account required

THE PRODUCTION LINE

Made in High Wycombe, Buckinghamshire

Every unit is manufactured to your exact specification in our High Wycombe facility. Glass arrives as jumbo sheets from Pilkington and Saint-Gobain; it leaves as a finished, gas-filled, dual-sealed unit — typically within 3–5 working days.

IGU production line - the glass moving through cutting, washing, spacer, gas fill and seal, QC and racking, under warm work-lights against a cool factory ambient CUTTING WASHING SPACER GAS & SEAL QC RACKING
High Wycombe Facility 12,400 units shipped last quarter
12.4k
Units last quarter
99.2%
On-time dispatch
0.18%
Seal-failure rate
4.9/5
Customer rating
Factory tour
Process

Quote to delivery, in days.

01

Spec your units

Use the calculator or send a CSV. Sizes, glass spec, gas fill, spacer — all configurable. Not sure how to measure? See our measuring guide.

02

Instant trade price

Net trade pricing returned in seconds. No account required, no minimum order.

03

Production

Dual-seal IGU line. Tested per batch. Standard lead 3–5 working days; jumbo 7–10.

04

Delivery

Pallet courier UK-wide or own-van delivery where available (London & Home Counties only, subject to capacity). Free collection from our High Wycombe factory.

How it works

Glass unit cross-section.

Explore the layers inside each glass unit. Switch modes to see gas fill, thermal performance and sound insulation.

Technical diagram
Glass unit cross-section
Interior 21°C ↔ −5°C Exterior ΔT 26°C · drag to adjust
Source
Outside: 80 dBInside: 46 dB
−34 dB
Interior 21 °C Exterior −5 °C 6 mm HIGH HEAT LOSS U-value: 5.8 W/m²K No thermal break Only ~20% UV blocked No coating — high solar gain risk No Low-E coating — UV and solar radiation pass through with minimal reduction Rw ≈ 28 dB Minimal attenuation Float / toughened glass U 5.8 · Rw 28 · No gas Interior 21 °C Exterior −5 °C WARM EDGE 4mm 20mm argon 4mm Ar Ar Ar Ar Ar Argon gas fill Argon atom (Ar) 67% lower conductivity than air — less convection Low-E U = 1.1 W/m²K vs 5.8 SGU · 81% reduction ~70% UV blocked g-value ≈ 0.63 · Low-E surface 2 Low-E coating on surface 2 blocks ~70% UV and reduces solar gain vs SGU −28 dB (pane) −6 dB (cavity) Rw ≈ 32–36 dB 28 mm overall · 4 + 20 argon + 4 · Warm edge TPS spacer · Low-E surface 2 Interior 21 °C Exterior −5 °C WARM EDGE WARM EDGE 4mm 16mm Ar 4mm 16mm Kr 4mm Ar Ar Ar Kr Kr Kr Dual cavity gas fill Argon (Ar) — outer Krypton (Kr) — inner Kr: 55% lower conductivity than Ar Maximises TGU thermal performance Low-E ×2 U = 0.5 W/m²K Passivhaus standard · 91% vs SGU −28 dB −6 dB −5 dB Rw ≈ 40–44 dB 44mm overall · 4 + 16Ar + 4 + 16Kr + 4 · Dual warm edge · Low-E surfaces 2 & 5 >95% UV blocked g-value ≈ 0.30 · Dual Low-E Dual Low-E surfaces 2 & 5 block >95% UV — prevents fading, reduces solar gain ALUMINIUM SPACER WARM EDGE (TPS) ALUMINIUM ❄ Cold bridge ❄ Cold bridge Thermal bridge Ψ ≈ 0.08 W/mK Condensation risk at cold edges WARM EDGE ✓ Thermal break ✓ Thermal break Warm edge Ψ ≈ 0.03 W/mK 62% less edge heat loss 6mm Single Glazed U 5.8 Rw 28 U 5.8 W/m²K 28mm Double Glazed U 1.1 Rw 34 U 1.1 W/m²K 44mm Triple Glazed U 0.5 Rw 42 U 0.5 W/m²K Performance comparison U-value (lower = better insulation) Rw sound rating (higher = quieter) Low-E coating
Technical cross-section showing glass panes, warm-edge TPS spacer bars, and cavity dimensions. Select a mode above to visualise gas fill, thermal or acoustic performance. Argon (outer cavity) and krypton (inner cavity on TGU) molecules shown with electron shells. Noble gases have 34–55% lower thermal conductivity than air, significantly reducing convective heat transfer between panes. Thermal performance visualisation. The gold Low-E coating reflects infrared back into the room. Drag the temperature slider to change exterior conditions and see heat flow intensity change live. Acoustic wave propagation shown as scrolling sinusoidal waves. Each glass pane attenuates approximately 28 dB; each cavity further reduces amplitude. Asymmetric pane thicknesses in high-spec units break coincidence dip. UV and solar radiation enter from the exterior. Low-E coating blocks 70–95% of UV depending on unit — protecting furnishings and reducing summer solar gain. The g-value (solar factor) measures how much solar energy enters: lower g-value = less solar gain.
5.8 W/m²K
U-value
28 dB
Rw sound
6mm
Thickness
—
Gas fill
1.1 W/m²K
U-value
32–36 dB
Rw sound
28mm
Overall
Argon
Gas fill
0.5 W/m²K
U-value
40–44 dB
Rw sound
44mm
Overall
Ar+Kr
Gas fill
0.08 W/mK
Ψ Aluminium
0.03 W/mK
Ψ Warm edge
62%
Less edge loss
No
Condensation risk
SGU 5.8
U-value W/m²K
DGU 1.1
U-value W/m²K
TGU 0.5
U-value W/m²K
VGU 0.4
U-value W/m²K

Want to run your own numbers? Try our weight and U-value calculators, or browse the full technical downloads library.

Why trade choose CSU

Trade pricing, direct from UK manufacture.

No middleman, no minimum order, no account required. Get pricing in seconds, units delivered in days.

Net trade prices
Direct manufacturer pricing. No retail markup. Volume tiers for regular orders.
Credit accounts available
BACS, card or trade credit account for regular customers. No upfront payment required once set up.
5-year warranty
Full seal-failure replacement cover. No fine print, no hassle.
Engineering support
Spec advice from real glaziers. Help with U-values, sizing and complex jobs.
What trade say

Trusted by glaziers UK-wide.

JM
Glazing contractor
★★★★★

“Quote in seconds, unit delivered in 4 days. Spec was exactly right. Best supplier we’ve used in 12 years.”

James M. — M&K Glazing Ltd

SL
Property developer
★★★★

“240-unit commercial fit-out. Hit every delivery slot bar one — bank holiday week pushed a drop by a day, but they kept us informed. Spec was spot on and zero remakes.”

Sarah L. — Project Manager, Skyline Construction

DR
Window fitter
★★★★★

“Trade pricing genuinely better than the bigger names. Same glass brands. Lead times half what we used to get.”

Daniel R. — D.R. Windows & Doors

Recent projects

Trade jobs, delivered to spec.

A snapshot of the commercial, residential and specialist work we manufacture for glaziers and contractors UK-wide.

Modern commercial glazing facade supplied by CSU Ltd, High Wycombe
240-unit commercial office facade — dark aluminium curtain wall glazing Commercial · Curtain Wall

240-unit commercial office façade

240units Low-EDGU 3 wkphased

Delivered in 3 phased drops to match the fit-out programme. Completed Nov 2025.

UK new-build housing estate street view — 84-plot residential triple-glazing scheme Residential Dev · Triple Glazed

84-plot new-build housing scheme

1,100units 0.6W/m²K rollingdelivery

Part L compliant spec, called off plot-by-plot over 9 months. Completed Feb 2026.

Listed townhouse sash window refurbishment — period brick facade with slim 14mm double glazing Heritage · Slim Sightline

Listed townhouse conservation refit

36units 14mmslim DGU 4 wklead

14mm slim units passed conservation officer inspection first time. Completed Jun 2025.

UK high-street shopfront glass frontage — EI60 fire-rated glazing fit-out Retail · Fire-Rated

High-street shopfront fit-out

18units EI60fire glass 5 wklead

EI60 glass supplied for building control approval. Completed Sep 2025.

Secondary school classroom block exterior with window banks — 44dB acoustic glazing Education · Acoustic

Secondary school classroom block

160units 44dBacoustic phaseddelivery

44dB acoustic spec installed over summer break, term unaffected. Completed Aug 2025.

Hotel bedroom interior with large glazed window — integral blind integral blind sealed units, hotel refurbishment Hospitality · Integral Blinds

Boutique hotel refurbishment

120units integral blindintegral 6 wklead

integral blind blinds sealed in-unit — no cleaning contract needed. Completed Apr 2026.

Delivery

Pallet courier UK-wide. Own-van where available.

We run our own refrigerated delivery vans covering London, Berkshire, Buckinghamshire, Hertfordshire and Surrey — safely transporting glass units on our own racking.

Own-van (when available) London & Home Counties only — subject to van capacity
Pallet courier UK-wide Specialist glass pallets — anywhere in mainland UK
Free collection from factory High Wycombe HP11 — Mon–Fri 8:00–5:00 · No charge
View delivery coverage
3–5
Day lead time
FREE
Factory collection
UK
Mainland coverage
0
Minimum order

*Own-van delivery available London & Home Counties only (subject to capacity). All deliveries quoted at cost. Free collection from factory always.

Sustainability

Built sustainably.

UK manufacture cuts shipping emissions. Glass cullet recycled at source. Energy-efficient production line and reusable steel pallets across our delivery network.

Read about our environmental commitments
Eco-friendly glass building with trees and reflective facade, sustainable architecture
100% cullet recycled
All offcuts back into the glass-making loop
UK supply chain
Sourcing minimises freight emissions
Low-carbon glass
Reduced-carbon Low-E glass options available on request
Reusable pallets
Steel A-frame pallets returned and reused
FAQ

Common trade questions.

Everything you need to know about ordering, lead times and glass specification.

View all FAQs

No account needed. Get an instant trade price online, then call or email to confirm your order. We accept BACS, card or credit account for regular trade customers.

Standard DGUs and TGUs: 3–5 working days. Jumbo units (over 3m): 7–10 days. Fire-rated and integral blind units: 10–15 days depending on specification.

No minimum order. We supply single units to full commercial projects. Delivery charges apply on small orders — collect free from our High Wycombe factory.

Yes — arched, circular, triangular and bespoke shaped units available. Send a drawing or DXF file. Lead time typically 7–10 days for shaped work.

30-second quote

Get a trade price in seconds.

No account, no minimum order, no callback queue. Spec it, price it, order it — all online.

Mon–Fri 8:00am–5:00pm
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