Double Glazed Windows Export in Foshan China: Double Glazed Aluminium Windows, Triple Glazing and FOB Pricing

What “Double Glazed” Means on a Purchase Order

A double glazed window is a sealed insulating glass unit (IGU) held in a frame. The unit, not the frame, sets most of the thermal result, and the unit is where most specification errors are made. Writing “double glazing” on a PO without the glass build-up, cavity gas, coating position and spacer type leaves the supplier free to supply a 4-6A-4 float unit with an aluminium box spacer, which has a centre-of-glass U-value of about 2.87 W/m²K and a whole-window value above 4.0 in a frame with no thermal break. That difference is not cosmetic: it is the gap between passing and failing a building-code U-value check.

Anatomy of one sealed unit

Sealed unit versus two panes in one frame

Site-assembled “double windows” – two single panes fitted into a frame with a reversible sash – are not IGUs. Their cavity is ventilated, so the cavity resistance collapses to the value of an unventilated air layer with an internal surface resistance on both faces, and the U-value lands around 3.4 to 3.8 W/m²K, close to a single pane with a storm window. For a thermally broken aluminium window the sealed unit is the only configuration that reaches code-level values.

Ug: How the Cavity Number Is Calculated

Centre-of-glass U-value is calculated with EN 673. The cavity is treated as a gas layer with a Nusselt number based on the Grashof and Prandtl numbers, in parallel with a radiative term driven by the two facing emissivities. Nothing in the calculation is proprietary, so a buyer can reproduce every number in the table below.

The calculation

Gap width: the optimum is flat, not narrow

Reading the table: an uncoated air-filled unit improves steadily up to about 16 mm and then reverses, because natural convection starts to short-circuit the cavity. With a Low-E coating and argon the optimum is also near 16 mm, and the curve is very flat between 12 and 20 mm, so cavity width is not where the money is. Krypton peaks much earlier because its lower conductivity makes convection dominate at a smaller gap.

Where the U-value actually comes from

Splitting the resistance of a 4-16Ar-4 Low-E unit: the coating is responsible for roughly 0.75 m²K/W of the cavity resistance and the gas for the remaining 0.16. In other words, the low-emissivity coating contributes about four times more than the gas fill. Argon buys 0.26 W/m²K over air in a 16 mm cavity; the coating buys about 1.5. Specifying argon without a coating is spending money on the smaller term.

From Ug to Uw: the Frame and the Spacer Decide

The number that goes on a compliance form is Uw, not Ug. EN ISO 10077-1 combines the glazing, the frame and the linear thermal bridge at the glass edge:

Full matrix: frame Uf × glazing × spacer

The matrix is built with a standard aluminium box spacer (Psi = 0.068 W/mK). Two conclusions follow directly. First, the cheapest way to lose compliance is to pair a good unit with a frame that has no thermal break: 4-16Ar-4 Low-E drops from 1.62 to 2.83 W/m²K simply by removing the polyamide strip. Second, the frame improvement from 14 mm to 34 mm polyamide is worth about 0.39 W/m²K, while moving from uncoated to Low-E glass is worth about 1.30. Glass first, frame second.

Spacer sensitivity at one frame

Double Glazed Aluminium Windows: Frame Selection

Double glazed aluminium windows are aluminium-framed openings carrying a sealed insulating unit. Aluminium is chosen for span, section depth stability and coating life; it is penalised by conductivity, so the thermal break is the specification that matters once the glass has been fixed.

Thermal break widths and what they buy

Alloy, temper and wall thickness

Main frame wall thickness runs 1.4 to 2.0 mm in residential profiles and 2.0 to 3.0 mm for mullions and hurricane-rated sections. EN 1999-1-1 applies a partial factor γ_M1 = 1.10, so the allowable design stress for 6063-T6 is 170 / 1.10 = 155 MPa. In practice window sections are deflection-controlled, not stress-controlled: at the L/200 serviceability limit the stress utilisation of a standard casement sash is typically under 30 %.

Coating

ISO 9227 salt-spray hours rank batches against each other; they are not a service-life prediction. A 1 000-hour result on a powder panel says the pretreatment line was under control that week, not that the window will last 30 years on a coast.

Aluminium Casement Windows: Sash Mass and Hardware

Aluminium casement windows are side-hinged sashes that close against a compression seal. The configuration has the best air-tightness of any opening type because the sash is pulled onto the gasket by the locking mechanism rather than sliding past it – which is why casement is the default choice wherever a U-value or an air-leakage target has to be met.

Sash mass drives every hardware choice

The jump from a 25 kg sash to a 96 kg sash on the same frame is the single most common cause of hardware failure in the field: the sash drops, the hinges run out of adjustment, and the locking points stop meeting their keeps. When a specification moves from double to triple glazing, the hinge and the espagnolette have to be re-specified at the same time.

Multi-point locking and compression

• Three to seven locking points on sashes taller than 1 500 mm; the top and bottom points carry the corner pull-in.
• Compression adjustment of 0.8 to 1.6 mm on the keep; without it the gasket cannot be pre-loaded after the frame settles.
• EN 12209 lock and strike: grade 3 durability is 200 000 cycles; grade 7 is not required for residential but is normal for apartment common areas.
• EN 13126-1 to -16 for window hardware; torque to operate should be measured and stated, not assumed.
• Stay arms on heavy sashes must be rated for the sash mass, not for the frame size.

Air, water and wind: what casement actually achieves

A supplier quoting “Class 7A” without saying A or B is quoting a protected condition. On an exposed facade the comparable figure is the B series, and 7B is only 300 Pa – roughly a 22 m/s gust. Read the test report, not the brochure line.

Double Hung Windows with Insulated Glass

Double hung windows carry two sliding sashes in a single frame. The type is specified mostly in North America and in retrofit work where the opening has to keep an existing aperture shape and the sash must not project. Fitting an insulating unit into a hung sash changes the balance hardware, not just the glass.

Sash weight and balance selection

A hung sash runs on a balance – a block-and-tackle, spiral, or constant-force spring – sized to the sash mass. Standard balances are supplied in narrow weight bands, so a glass change of 5 kg can push a sash out of band and leave it either drifting open or slamming shut. This is a specification step that is frequently missed.

Above roughly 68 kg the single-balance arrangement stops being adequate and the sash needs two balances or a constant-force spring cartridge, which requires a deeper jamb channel. That is a frame decision, not a glazing decision, so it has to be settled before the extrusion is ordered.

Thermal and air performance of hung sashes

A hung sash slides in a channel, so it cannot be pulled onto a compression gasket the way a casement sash is. Air permeability of a well-built hung window sits at EN 12207 Class 2 to 3 against Class 3 to 4 for casement, and the meeting rail creates a second linear thermal bridge the casement does not have. Where the facade has a U-value target, casement is the safer choice; where the project is a retrofit with a fixed aperture, hung is often the only geometry that fits.

North American ratings

• NAFS / AAMA / WDMA 101 / I.S. 2 / A440 performance grades R (residential), LC (light commercial), CW (commercial), AW (architectural).
• Performance grade numbers (PG25 / PG40 / PG50) are the design pressure in pounds per square foot: PG40 = 40 psf = 1.92 kPa.
• Miami-Dade NOA is a separate approval; it covers only the tested combination, so a 16 ft wide approval does not extend to an 18 ft unit.
• ASTM E283 (air), E331 (water), E330 (structural) are the test methods behind the grade.
• EN 12208 B-series water ratings cap at 7B = 300 Pa; NAFS PG40 is 1 920 Pa. The two systems are not interchangeable – state which one the report was issued under.

More detail on hung geometry and sizes is in house windows: double hung, basement and villa window specs and single-hung vs double-hung selection.

Triple Glazed Aluminium Windows: When the Third Pane Pays

Triple glazed aluminium windows add a third pane and a second cavity. The thermal return is real but smaller than most buyers expect, and the weight return is much larger than most buyers expect.

What the third pane buys

Going from double Low-E to triple Low-E moves Uw from 1.62 to 1.31 – about 0.31 W/m²K – and costs USD 32 to 48 per m². That is roughly USD 130 per unit of U-value saved per square metre of window. Compare with the warm-edge spacer at USD 6 to 9 for 0.046, which is roughly USD 160 per unit – comparable, but the absolute gain is small. The honest conclusion: the third pane is bought to reach a specific code number (Passive House Uw 0.80, Scandinavia, or a Minergie-style requirement), not as a general upgrade.

Weight, hardware and opening forces

Acoustic benefit is smaller than expected

Tripling the glass adds mass but the two cavities are usually similar, which puts their mass-spring resonances close together. A 4-12-4-12-4 build typically measures Rw 33 dB against Rw 30 for a 4-16-4 – three decibels for a 23 % weight increase. For acoustic work an asymmetric build with a laminated inner pane is the better spend. See soundproof window construction.

Glass Thickness, Wind Load and Safety Glazing

Pane thickness is set by wind pressure and pane area, not by thermal performance. The governing relation for a rectangular pane simply supported on four sides is σ_max = 0.266 · p · a² / t² with p in kPa, a the short side in m and t in mm, giving σ in MPa. Allowable stress is f_k / γ_M with γ_M = 1.8.

Maximum short-side span by glass type

In a symmetric insulating unit each pane carries roughly half of the short-term load, so the effective span is larger than for a single pane. The table below gives the short-side span for a symmetric tempered IGU under the same pressures.

Note the shape of the result: going from 1.0 kPa to 2.0 kPa halves the allowable span squared, so a pane that is comfortable at 1.5 m needs to roughly double in thickness to stay at 1.5 m when the design pressure doubles. This is why coastal and high-rise projects drive glass thickness, and why the wind map location belongs on the PO.

Safety glazing and heat-soak

Heat-soak costs USD 4 to 7 per m² and removes the nickel-sulphide inclusion risk that otherwise shows up as a spontaneous break one to three years after installation. On a 500-window project with 0.15 % inclusion rate that is about one unexplained breakage per year; the test is cheaper than the call-out.

Condensation Risk at the Glass Edge

Condensation appears first at the glass edge, where the spacer and the frame meet. The temperature factor f_Rsi is the standard check: it is the ratio of the internal surface temperature difference to the full indoor-outdoor difference. EN ISO 13788 treats f_Rsi >= 0.70 as the mould threshold. A simpler field check is to compare the surface temperature against the dew point of the room air.

Dew point of room air

Surface temperature by build

At 40 % indoor humidity the dew point is 12.5 C at a room temperature of 20 C and -5 C outside. An uncoated double unit in a 14 mm frame shows an edge temperature well below that, which is why condensation is reported on windows that are otherwise code-compliant. The frame and the spacer, not the glass, usually need to change.

What actually removes condensation

• Warm-edge or TPS spacer: raises the edge temperature by 2 to 4 K for USD 6 to 12 per m².
• Wider polyamide break: 14 mm to 24 mm raises the frame surface temperature by 3 to 5 K.
• Internal air movement: a sill that blocks the curtain of warm air over the glass can cause condensation on a perfectly good window.
• Room humidity: dropping RH from 60 % to 45 % moves the dew point from 12.5 C to 7.6 C worth more than most hardware upgrades.
• Reveal insulation: an uninsulated reveal around the frame creates a cold band that behaves exactly like a thermal bridge.

Acoustic Build-ups

Sound reduction through an insulating unit is governed by mass, cavity width and – most importantly – by avoiding coincidence between the two panes. Two panes of the same thickness over the same cavity have a mass-spring-mass resonance that produces a measurable dip in the 200 to 400 Hz band.

Measured build-ups

The asymmetric 6-16Ar-4 build measures about 1 dB better than a symmetric 6-16Ar-6 for the same total mass, because the two panes no longer share a coincidence frequency. A laminated inner pane with a 0.76 mm PVB interlayer is worth 3 to 5 dB on its own and is the standard answer for sites near roads or railways.

Frame sealing dominates the installed result

A 1 mm continuous gap around a sash is 0.30 % of the window area but reduces the installed reduction from Rw 40 dB to about Rw 25 dB. In practice the installed acoustic result is set by the compression seal and the perimeter joint, not by the glass build. Specify the seal and the installation detail together with the glass.

Solar Control and Light Transmission

The g value (solar heat gain coefficient in North America) and the light transmission are set by the coating and the glass body, and they move in the same direction: reducing solar gain almost always reduces daylight. The correct selection depends on orientation and on whether the building is heating-dominated or cooling-dominated.

Coating and body tint options

Selectivity – the ratio of light transmission to g value – is the number to compare. A coating with LT/g above 1.6 delivers noticeably more daylight per unit of solar heat rejected, which matters on a west elevation where the afternoon gain arrives at the same time as the cooling peak.

Orientation rule

• North (northern hemisphere): maximise gain. g 0.60 to 0.72, LT above 0.75.
• South: moderate gain with shading. g 0.35 to 0.50 in cooling-dominated sites, 0.60 to 0.70 in heating-dominated sites.
• East and west: minimise gain. g 0.28 to 0.40; fixed shading is more effective than coating at these angles because the sun is low.
• Roof and skylight: g below 0.35 and laminated inner pane for safety – see skylight and roof window specifications.
• A 10 m² west-facing clear-glass opening admits about 8 kW of solar gain at peak; the same area at g 0.30 admits about 2.9 kW.

Gas Retention, Leakage and Altitude

An argon-filled unit is sealed, not hermetic. EN 1279-3 sets the acceptance criteria: initial gas concentration at least 90 % and a leakage rate of no more than 1 % per year. That rate is what turns a specification into a lifetime.

Argon concentration and Ug

Service life projection at the EN 1279-3 limit

At the EN 1279-3 limit the unit loses about 0.006 W/m²K per year, so a unit specified at 1.08 is around 1.15 to 1.20 after 20 years. That is within the noise of the calculation; what matters more is that a failing seal lets moisture in, and the desiccant saturation shows up as fogging long before the U-value has moved measurably.

Altitude: the pressure differential nobody specifies

An insulating unit sealed at a factory near sea level carries an internal pressure of about 101 kPa. Transport it to a site at 2 640 m where the ambient pressure is 73 kPa and the two panes bow outward by the difference. This is the cause of “pillowed” units and of seal failures that get blamed on manufacturing.

Two more pressure effects are worth writing into the specification. Units that travel by air freight see the same differential in reverse on descent, and units installed behind an external shading device can reach 70 C in the cavity, raising the internal pressure by about 12 kPa on top of the altitude term.

Certification and Test Evidence

Four documents cover most of what a buyer can reasonably ask for. Each one has a scope, and the scope is where suppliers and buyers disagree.

What each document covers

Checking the numbers

• Ask for the declared U-value and the size of the tested or simulated specimen. A U-value declared on a 1.23 x 1.48 m reference window is not the value for a 1.5 x 2.4 m unit, because the frame fraction and the edge length change.
• Ask which spacer was in the tested specimen. Substituting an aluminium box spacer for the warm-edge spacer in the tested build changes Uw by 0.03 to 0.09.
• For gas-filled units ask for the EN 1279-3 certificate and the date of the batch test, not a generic product sheet.
• For safety glazing ask for the EN 12150 fragmentation record and, where heat-soak was specified, the EN 14179-1 furnace log.
• For North American projects confirm whether the report is issued under NAFS or EN. EN 12208 Class 7B (300 Pa) is not equivalent to a NAFS PG40 (1 920 Pa).

Related certification detail for the European market is covered in fenetre aluminium: AEV, Acotherm and RE2020 and for Iberian projects in ventanas de aluminio: CTE Uw and AEV.

FOB Pricing Matrix

All figures below are FOB Foshan, per square metre of window area, for powder-coated aluminium frames with either aluminium casement or fixed lights, standard hardware and no customs or inland costs. Volume tiers are per order, not per container.

Configuration by volume tier

Upgrade adders

For a cost comparison across opening types see double glazed windows and aluminum window frame cost data and aluminium windows and doors: double and triple glazed specs.

Commercial Terms and Inspection Points

Standard terms

Inspection before shipment

1. Dimensional check against the approved shop drawing, 3 units per size.
2. Glass build verification: measure the overall unit thickness and check it against the ordered build (for example 5-16-5 = 26 mm).
3. Coating thickness: 8 to 12 readings per order with a dry-film gauge; reject below 60 um for Qualicoat Class 2.
4. IGU dew point: EN 1279-2 spot check on one unit per 200.
5. Operating force: 5 units cycled 25 times, force measured per EN 13115.
6. Dry assembly of one complete unit per size with photographs – this step catches more errors than all the others combined.
7. Crate drop and tilt marking, corner protection, and desiccant bags in every crate.
8. Container loading photographs: door open, half loaded, and sealed.

Of the above, the dry-assembly photograph is the one that pays for itself. It exposes handed hardware, wrong keep positions and reversed sashes before 300 units are built.

Packing and Container Maths

Window crates are glass-limited, not frame-limited: glass cannot be nested, so the crate volume is set by the glass footprint times the stack height. Knock-down frames save little because the glass is unchanged. The practical conclusion is that shipping assembled windows is normally correct, and the optimisation is crate height and payload utilisation.

Units per 40 ft high cube

Every configuration in the table is volume-governed, but the margin narrows fast: the 3.6 m² unit with an 8.8 mm acoustic laminated inner pane reaches 99 % of the 25 t payload at 137 units. One step heavier – a third pane plus laminate – would flip it to weight-governed, and then the container is half empty by volume while the truck is full. That is the point at which splitting the order across two containers, or shipping glass and frames separately, starts to pay.

Crate design

• Vertical stacking on edge in an A-frame crate, glass face to glass face with interleaving paper or foam – never flat, and never glass against frame.
• Crate height limited to the reach of the site handling equipment: 8 to 10 units for small sizes, 5 to 6 for 3.6 m² units.
• Corner protection on all four verticals and a full-height timber spine board.
• Desiccant at 20 g per m³ of crate volume; sealed internal polythene shroud.
• Maximum crate mass 900 kg for sites with a forklift, 400 kg for stair-carry sites.
• Tilt and shock indicators on two faces of every crate; the photographs go into the claim file if a crate arrives damaged.

Landed Cost and Duty

FOB is roughly half of what an installed window costs at a European or North American site. The worked example below uses the reference size (1.82 m², 238 units per container = 433 m² per 40 ft high cube) and a C4 configuration at the 300 to 799 m² tier.

Two ports, four duty scenarios

Freight allocation is USD 5.54 to 7.39 per m² – about 4 to 5 % of the FOB price. Duty is the variable that matters: between 0 % and 45 % the delivered price swings by about USD 62 per m², which is larger than the entire freight component and comparable to the gap between a 14 mm and a 34 mm thermal break.

Sensitivity: what changes the decision

• Order size: moving from 120 m² to 800 m² moves the FOB tier by about 12 %, more than any freight negotiation.
• Glass build: triple glazing adds USD 32 to 48 per m² FOB and about 4 % more weight, which does not change the container count for most sizes.
• Laminated inner pane: USD 22 to 34 per m² and 8 to 12 kg/m², which does change the crate count on large units.
• Currency and steel/aluminium surcharges: extrusion prices are usually quoted with a metal-price adjustment clause – ask whether the quote is fixed or indexed.

Installation and Commissioning

Sequence

1. Check the structural opening against the approved shop drawing before unpacking. A 15 mm error in the opening cannot be corrected with fixings.
2. Set the frame on packers at the fixing points only; never pack under the middle of a sill.
3. Fix through the frame at 150 mm from each corner and at 500 to 600 mm centres. Fixings must not pass through the polyamide thermal break.
4. Check frame squareness on both diagonals before glazing: tolerance 2 mm on a 2 400 mm frame.
5. Fit the sash, glaze, then fit the beads from the internal side on ground floor and from a protected side above.
6. Set the compression on the locking keeps so a 0.2 mm feeler gauge meets resistance at all locking points.
7. Apply the perimeter seal: airtight membrane inside, weather-tight but vapour-open membrane outside. Neutral-cure silicone only – acetoxy cure attacks anodised finishes and polyamide.
8. Commission: cycle every sash 10 times, measure operating force, verify drainage slots are clear by pouring water into the frame channel, and record the results.

Drainage and pressure equalisation

A window frame is a channel that will collect water. The frame must have a pressure-equalised outer chamber drained to the outside through slots of at least 5 x 25 mm, and the slots must be fitted with baffles or flaps in exposed positions. The most common installation defect is sealing the drainage slots with the perimeter silicone bead – the frame then fills on the first storm and leaks through the transom joints.

Failure Modes

Six failures and where they are decided

Four of the six are decided before the order reaches the factory, which is the practical argument for spending time on the glass build-up and the spacer rather than on negotiating the unit price.

Warranty exclusions to read before signing

• Glass breakage after delivery – covered by marine insurance, not by the product warranty.
• Condensation – excluded almost universally, because it depends on room humidity and ventilation, which the supplier does not control.
• Exposure above the coating class – a Class 1 powder installed 300 m from the sea is normally excluded.
• Units installed without the specified drainage or with a sealed drainage path.
• Damage from alkaline building materials: wet cement at pH 12 to 13 attacks aluminium and voids the finish warranty.

Project Records

Utrecht, Netherlands – 240 windows, 8-storey apartment retrofit

Configuration C4: 24 mm polyamide break, 5-16Ar-5 Low-E with a warm-edge hybrid spacer, Uw 1.62 W/m²K, soft-coat emissivity 0.037, argon certified to EN 1279-3. Total 437 m² of window area on 240 openings, one 40 ft high cube plus one 20 ft. FOB USD 137 per m² at the 300 to 799 m² tier; delivered and installed USD 232 per m² at 6 % duty. The local alternative quoted was USD 339 per m² installed, a difference of 31.6 % or USD 46 750 on the package. Twelve months after handover there were zero condensation complaints against eleven logged on the previous single-glazed aluminium frames, and two service calls, both for handle adjustment after the first heating season.

Denver, United States – 68 windows, townhouse development at 1 609 m

Configuration C5 with a 6.4 mm laminated inner pane for hail, warm-edge spacer, capillary breather tubes on every unit for the 1 609 m elevation, NAFS R-PG40 with ASTM E1886 / E1996 small-missile compliance. Frame 34 mm polyamide, Uf 2.0, Uw 1.51. Delivered and installed USD 268 per m² against a local quote of USD 402 per m², a saving of 33.3 %. Without the breather tubes the site team measured an outward bow of 2.1 mm on the first two units delivered without them, which was the reason the tubes were retro-ordered for the balance of the shipment; the visual distortion was visible in reflected images at the third floor.

Selection Matrix

The decision between single, double and triple glazing, and between casement, hung and fixed, is a decision about which number has to be met. The table below is the short version.

Glazing levels compared

Opening type compared

Where the project brief calls for aluminum casement windows – the North American spelling of the same product – the specification logic is identical: the sash is hinged and compressed, so air performance is the best available and the governing limits are hinge class and sash mass. The only differences are the ratings system (NAFS instead of EN) and the glass safety code (ANSI Z97.1 instead of EN 12600).

When aluminium is the wrong answer

• Heritage or conservation projects where the sightline has to match a timber section.
• Budget below roughly USD 90 per m² delivered, where uPVC reaches the same U-value for less and the larger profile depth is acceptable.
• Sites with on-site cutting and fabrication only, because thermal break profiles cannot be modified in the field.
• Direct contact with wet concrete or CCA-treated timber without a separation layer – both attack aluminium.
• Where a very slim sightline under 40 mm is required and the span exceeds about 1 200 mm; steel or a structural glazed system is the answer.

RFQ Checklist

Technical – eight lines to send

1. Glass build-up in full: pane thickness, coating and surface number, cavity width, gas type and concentration, spacer type.
2. Required Uw and the calculation standard: EN ISO 10077-1 or NFRC 100, plus the reference size the value is declared for.
3. Wind load: design pressure in kPa or psf, and the standard (EN 12210, AS 2047, NAFS PG).
4. Safety glazing requirement: tempered, heat-soak, laminated, and the class (EN 12600, ANSI Z97.1, CPSC Cat II).
5. Acoustic and solar targets: Rw in dB, g value and light transmission.
6. Site elevation above sea level, and whether breather tubes are required.
7. Frame: thermal break width, alloy and temper, wall thickness, coating class.
8. Ratings and documents needed: CE DoP, EN 1279-3 certificate, NFRC label, NOA, and whether third-party testing is required.

Commercial – eight lines to send

1. Total quantity in square metres and in number of openings, plus a size schedule.
2. Target tier and whether partial shipments are acceptable.
3. Incoterm and port.
4. Required documents: certificate of origin, test reports, packing list with crate dimensions and masses.
5. Spare parts percentage and the list of items required.
6. Warranty period and what it excludes.
7. Payment terms and whether an L/C is involved.
8. Whether a sample unit is required before the production order, and who pays for it.

Glossary and Standards

Terms

Standards index

Related Reading

Window series

• Aluminium windows and doors: frame specs and double and triple glazed pricing
• House windows: double hung, basement and villa window specs
• Aluminum sliding window: frame specs, pricing and performance data
• Sliding windows wholesale: aluminium specs and pricing
• Door window accessories: hardware, screens and roller shutter torque
• Windows and doors wholesaler: accessories and soundproof specs
• Soundproof windows: construction and Rw data
• Rogenilan windows and doors: full specification set

Glazed structures and other markets

• Green house builds: glass greenhouse and aluminium frame specs
• Sunrooms 4 season: aluminum sunroom and conservatory specs
• Wintergarten wholesale: aluminium conservatory specs
• Skylight systems: roof window, retractable roof and sunroof specs
• Fenetre aluminium: AEV, Acotherm and RE2020 compliance
• Baie vitree: glazed bay and coulissante systems, Uw data
• Janelas de aluminio: ABNT requirements and FOB data
• Double glazed windows and aluminum window frame cost data
• Ventanas de aluminio y cristal: CTE Uw and AEV