Aluminum
Slim frames, big glass and any color, with thermal breaks that make aluminum work in a Northwest winter.
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Old aluminum windows earned a bad name here. The single-pane sliders in 1960s ramblers ran cold, dripped condensation and left black mold on the sills. Modern European aluminum is a different animal. The inside and outside of the frame are separated by a wide insulating barrier, the glass is triple-pane, and the sash closes against two or three gaskets with locks all around. What you keep from aluminum is the good part: strength. Strength means narrow frames, tall sashes and heavy glass that wood and uPVC can't carry.
What is a thermal break, and why does it matter?
Aluminum conducts heat very well. Without a break, the inside face of the frame gets almost as cold as outside, and that's where condensation forms. The wider and better insulated the break, the warmer the frame. Our systems use breaks from about 34 mm upward, and the high-insulation versions (SI, HI+, Aero) add foam or aerogel inserts in the break zone.
Where aluminum earns its place in Seattle
- View walls and tall glass. Lake, Sound and mountain views want as little frame as possible.
- Modern houses and DADUs. Crisp lines in black, bronze or any RAL color.
- Steel-window renovations. Thin, steel-look profiles without steel's cold frame and rust.
- Passive House builds. Our deepest aluminum systems reach very low frame U-factors.
- Doors. The same systems make matching entry, terrace and pivot doors.
Aluminum lets the frame get out of the way. That's what you're paying for.
How the eight systems differ
Think of them in four groups.
- Core performance: MB-79N Pro for value, MB-86N for size and weight.
- Slim and steel-look: MB-Slimline for the narrowest sightlines, MB-Ferroline Pro and SlimLine Elite for the look of steel windows.
- Architectural: MasterLine 8 Elite for custom homes with many style options.
- Passive House: MasterLine 10 Elite and MB-104 Pro.
See also our steel-look windows guide and Passive House windows.
The honest trade-offs
Aluminum costs more than uPVC for the same opening. Even with a good thermal break, a slim aluminum frame usually rates a little worse than a deep uPVC frame of the same price, so on a tight budget uPVC gives more insulation per dollar. And powder coat, while very durable, can be scratched; touch-up is possible but never invisible.
Aluminum systems compared
| System | Best for | U-factor from | SHGC | Frame depth | Glass up to | Sound (Rw) | NFRC certified |
|---|---|---|---|---|---|---|---|
| MB-79N Pro | Value aluminum | 0.17 | — | 70 mm frame / 79 mm sash | 63 mm | — | Certified |
| MB-86N | Big, heavy glass | 0.25 (casement) | 0.17–0.42 | 77 mm frame / 86 mm sash | 67.5 mm | 48 dB | —* |
| MB-Slimline | Narrowest sightlines | 0.15 | 0.17–0.42 | 68.5 mm | 81 mm | 42 dB | —* |
| MB-Ferroline Pro | Steel look, renovation | 0.14 | 0.09–0.38 | — | 61.5 mm | 47 dB | —* |
| SlimLine Elite | Slim steel look | 0.23 | 0.16–0.53 | 3.0–3.9″ | 55 mm | 47 dB | Certified |
| MasterLine 8 Elite | Architectural custom | 0.28 | 0.17–0.42 | 77 mm | 68 mm | 45 dB | —* |
| MasterLine 10 Elite | Passive House | 0.15 | 0.14–0.38 | — | — | 47 dB | —* |
| MB-104 Pro | Most insulated | — | 0.17–0.42 | 95 mm | 81 mm | 48 dB | —* |
U-factor in Btu/h·ft²·°F, best value from product data. Sound: European Rw with acoustic glass, not US STC. *— NFRC rating: ask us for current status for your project.
Aluminum window questions
Are aluminum windows cold?
Do aluminum windows condense?
Will the finish hold up in salt air near the Sound?
Can I have different colors inside and out?
Planning big glass?
Send drawings or photos of the openings. We'll match a system to the sizes and the look.
System cross-section 
System cross-section 
Inspiration: European project overseas
Photos are illustrative and not necessarily this exact system.
No. 01
MB-79N Pro aluminum
Aluminum, without the premium.
MB-79N Pro: value European aluminum window for remodels, spec builds and DADUs. Tilt-and-turn, outswing casement and hidden-sash versions.
Specifications
Performance
- U-factor
- from 0.17 Btu/h·ft²·°F (best configuration, our product data). Your quote lists the value for each window.
- SHGC
- depends on glass; your quote lists it
- NFRC rating
- Certified
Construction
- Depth
- 2.76″ (70 mm) frame / 3.11″ (79 mm) sash; door leaf 2.76″ (70 mm)
- Chambers
- 3 (center chamber is the thermal break, 33.5 or 36 mm wide)
- Insulation levels
- 3 in the family (E, ST, SI); we offer SI
- Seals
- Two-component center gasket + glazing gaskets (SI version)
- Glass thickness
- 1.5–54 mm in the fixed frame; 10.5–63 mm in the sash
- Sightline
- from 2.0 in (50.5 mm) fixed; 3-3/4 in (95 mm) frame plus sash
- Largest sash
- 2700×1350 or 2150×1700 mm, up to 160 kg (353 lb)
Options
- Opening types
- Tilt-and-turn, turn, tilt, fixed, awning, outswing casement, hidden sash, tilt-slide; single and double entry doors; storefront with doors
- Hidden-sash frame
- Type A partly covers the sash; type B covers it fully
- Hardware
- Euro-groove; concealed hinges available
- Colors
- RAL powder-coat colors; ask about dual color
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms
System cross-section
Photos are illustrative and not necessarily this exact system.
No. 02
MB-86N aluminum
For the big openings.
MB-86N: European aluminum window for large, heavy triple glass. U-factor from 0.25 (casement), glass up to 67.5 mm, ST, SI and Aero versions.
Specifications
Performance
- U-factor
- from 0.25 Btu/h·ft²·°F (casement)
- SHGC
- 0.17–0.42
- Sound
- up to 48 dB with acoustic glass (European Rw, not STC)
- NFRC rating
- Ask us for current status for your project
Construction
- Depth
- 3.03″ (77 mm) frame / 3.39″ (86 mm) sash
- Chambers
- 3, two-component center gasket
- Glass thickness
- 24–67.5 mm
- Max height
- depends on configuration; ask us
- Thermal versions
- ST, SI, Aero
Options
- Opening types
- Fixed, turn, tilt-and-turn, hidden sash (US), doors, folding door
- Colors
- RAL powder coat, anodized, dual color
- Nailing fin
- Available
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms
System cross-section
Photos are illustrative and not necessarily this exact system.
No. 03
MB-Slimline aluminum
Less frame. More Northwest.
MB-Slimline: very narrow visible aluminum frames, hidden-sash option and glass up to 81 mm thick. For views, light and minimalist homes.
Specifications
Performance
- U-factor
- from 0.15 Btu/h·ft²·°F
- SHGC
- 0.17–0.42
- Sound
- up to 42 dB (European Rw, not STC)
- NFRC rating
- Ask us for current status for your project
Construction
- Frame depth
- 2-11/16″ (68.5 mm)
- Thermal break
- Polyamide
- Glass thickness
- up to 81 mm (triple or quadruple)
- Max height
- depends on configuration; ask us
Options
- Opening types
- Inswing turn, tilt, tilt-and-turn, fixed; visible or hidden (SG) sash
- Colors
- Powder coat and anodized
- Nailing fin
- Available
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms
System cross-section
Photos are illustrative and not necessarily this exact system.
No. 04
MB-Ferroline Pro steel-look
The steel window, rebuilt for a wet climate.
MB-Ferroline Pro: the look of steel windows in thermally broken aluminum. Industrial and Steel-look profiles, renovation frames, U-factor from 0.14.
Specifications
Performance
- U-factor
- from 0.14 Btu/h·ft²·°F
- SHGC
- 0.09–0.38
- Sound
- up to 47 dB (European Rw, not STC)
- NFRC rating
- Ask us for current status for your project
- Security
- Up to RC2 (European burglar-resistance class)
Construction
- Base
- MB-86 technology; ST and SI thermal versions
- Glass thickness
- up to 61.5 mm
- Max height
- about 9.5 ft
Options
- Profiles
- Industrial, Steel-look
- Opening types
- Inward turn/tilt/tilt-and-turn, outward side-hung/top-hung, fixed
- Renovation frames
- Ask us whether one suits your house
- Colors
- Powder coat; black, bronze and RAL
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms
Product photo 
System cross-section 
Product photo
Photos are illustrative and not necessarily this exact system.
No. 05
SlimLine Elite steel-look
The steel-window look, NFRC certified.
SlimLine Elite on Reynaers SlimLine 38: slim steel-look aluminum windows, inswing/outswing, NFRC certified, U-factor from 0.23. Installed around Seattle.
Specifications
Performance
- U-factor
- from 0.23 Btu/h·ft²·°F
- SHGC
- 0.16–0.53
- Sound
- up to 45 dB (European Rw, not STC; system data)
- NFRC rating
- Certified
- European test classes
- Air 4 · Water 9A · Wind C4 · RC2
Construction
- System
- Reynaers SlimLine 38
- System depth
- 3.0–3.9″
- Chambers / gaskets
- 3 / 3
- Glass thickness
- 15–55 mm, double or triple
- Size range
- H 23.6″–9′10″, W 17.7″–3′11″, up to 170 kg per sash
Options
- Variants
- Classic, Ferro, Cubic
- Opening
- Inswing and outswing; fixed
- Options
- Concealed hinges, concealed drainage, flyscreen, glass corner
- Nailing fin
- Available
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms
System cross-section 
Product photo 
Product photo
Photos are illustrative and not necessarily this exact system.
No. 06
MasterLine 8 Elite aluminum
One system, many styles.
MasterLine 8 Elite on Reynaers MasterLine 8: architectural aluminum windows with Functional, Renaissance and Deco styles. U-factor from 0.28.
Specifications
Performance
- U-factor
- from 0.28 Btu/h·ft²·°F
- SHGC
- 0.17–0.42
- Sound
- up to 45 dB (European Rw; system data Rw 46 (0;−3) dB in a tested configuration)
- NFRC rating
- Ask us for current status for your project
- European test classes
- Air 4 · Water E900 · Wind C5
Construction
- System
- Reynaers MasterLine 8
- Frame depth
- 3″ (77 mm)
- Glass thickness
- up to 68 mm
- Insulation levels
- 3, incl. HI+
- Size range
- H 1′11.6″–9′2″, W 1′5.7″–5′6.9″, sash up to 300 kg
Options
- Styles
- Functional, Renaissance, Deco
- Options
- Concealed hinges, concealed drainage, flyscreen, balustrade, motorized, glass corner
- Doors
- Matching sliding and pivot doors
- Nailing fin
- Available
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms
System cross-section 
Product photo 
Product photo
Photos are illustrative and not necessarily this exact system.
No. 07
MasterLine 10 Elite aluminum
Passive-level performance in a slim aluminum frame.
MasterLine 10 Elite on Reynaers MasterLine 10: aluminum windows engineered for passive and very low-energy homes. U-factor from 0.15.
Specifications
Performance
- U-factor
- from 0.15 Btu/h·ft²·°F
- SHGC
- 0.14–0.38
- Sound
- up to 47 dB (European Rw, not STC)
- NFRC rating
- Ask us for current status for your project
- Passive House
- Designed for passive buildings; ask for the documents for your configuration
Construction
- System
- Reynaers MasterLine 10
Options
- Options
- Concealed hinges, concealed drainage, flyscreen, balustrade, motorized, glass corner
- Opening types
- Ask us for your project
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms
System cross-section
Photos are illustrative and not necessarily this exact system.
No. 08
MB-104 Pro passive aluminum
Our warmest aluminum frame.
MB-104 Pro: our most insulated aluminum window. 95 mm frame, SI and Aero versions, glass up to 81 mm for triple or quadruple glazing.
Specifications
Performance
- U-factor
- your quote lists the value for each window
- SHGC
- 0.17–0.42
- Sound
- up to 48 dB (European Rw, not STC)
- NFRC rating
- Ask us for current status for your project
- Passive House
- Certification depends on configuration; ask for the documents for yours
Construction
- Frame depth
- 3-3/4″ (95 mm)
- Seals
- 3 sealing layers
- Glass thickness
- up to 81 mm (triple or quadruple)
- Versions
- SI, Aero
Options
- Nailing fin
- Available
- Opening types
- Ask us for your project
Ordering
- Lead time
- 3–4 months; made to order and shipped by sea freight
- Warranty
- 20-year limited manufacturer warranty; 3-year installation warranty. See warranty terms