Slim aluminum windows from Bertrand

What are aluminum windows?

Aluminum windows use a metal frame that is strong enough to stay narrow. Bertrand calls them “a modern solution that combines exceptional durability and elegance.” Narrow frames mean more glass and less frame in the view. Bertrand also notes that “thanks to narrow profiles, the surface of a glass pane looks bigger.”

Honey Rock works with Bertrand for aluminum windows. Bertrand is a maker in Luzino, Poland. Its aluminum range runs from simple partitions to thermally broken window systems. Sun uses aluminum only as a cladding, covered on the clad wood windows page.

What does a thermal break do in an aluminum window?

Aluminum moves heat fast. A thermal break is an insulating barrier in the frame. It separates the inside metal from the outside metal and slows heat flow.

Bertrand’s MB-79N Casement “features a thermal break.” Its SI variant is “equipped with additional insulating inserts between the thermal breaks.” Bertrand also says much of its range is available in a “HI” version with special inserts in sections that “reduce their thermal conductivity.” Read about thermal breaks in steel too, because the idea is the same.

Which Bertrand aluminum families can Honey Rock offer?

Bertrand lists these families on its aluminum windows page. Numbers are in the units the maker prints.

Family	Type	Published thermal number	Published size or weight
MB-79N Casement	Outward opening	Uw from 0.74 W/(m²K)	Glazing to 2.48 in (63 mm) in the sash
MB-79N CSF	Slim outward opening	Uw 0.93 to 0.97 W/(m²·K)	Fixed frame 1.39 in, sash 2.38 in, sash up to 176 lb
MB-86N	Casement, tilt-and-turn	U-factor 0.25 to 0.35 W/(m²·K)	Up to 10 ft tall
SlimLine 38	Inward or outward opening	Uf 1.9, Uw 0.96 W/m²K	Height 23.6 in to 9 ft 10 in, width 17.7 in to 3 ft 11 in
ConceptSystem 77	Tilt and turn, outward opening, fixed	1.9 W/m²K	Tested frame 94.5 x 141.7 in
Masterline 8	Window system	Uf 1.3, Uw 0.88 W/m²K	Height 1 ft 11.62 in to 9 ft 2.236 in

All values come from Bertrand’s family pages. Ask for the system drawing for your size.

What is special about each family?

• MB-79N: the casement system shares parts with the MB-79N family. The CSF adds a hybrid hinge that supports sashes up to 176 lb. See casement and awning windows.
• MB-86N: comes in standard, SI (enhanced insulation) and hidden sash (US) variants. It also has a fold-line door version.
• SlimLine 38: three variants: Classic, Ferro and Cubic. Bertrand says it suits “the renovation of buildings with original steel-framed windows.” Options include concealed hinges and concealed drainage.
• ConceptSystem 77: Bertrand lists it with RC2 and RC3 security classes, plus air and water classes. It is the system Bertrand lists as Miami Dade NOA rated.
• Masterline 8: three insulation levels, sashes up to 300 kg. The page converts Uw to Btu units.

How does aluminum compare with steel?

Both can give narrow, modern frames. Steel is the classic narrow-frame metal. Bertrand offers aluminum in a rich color palette and publishes thermal and size numbers for each family. SlimLine 38 is “inspired by the look of narrow steel profiles.” Jada makes the steel in the Honey Rock lineup. Read the full steel vs aluminum windows guide and clad wood vs steel vs aluminum frames.

	Aluminum (Bertrand)	Steel (Jada)
Frame	Thermally broken aluminum	Thermally broken steel
Published sightline	1.39 in fixed, 2.38 in sash (CSF)	None, “narrow sightlines”
Published thermal numbers	Uw, Uf and U-factor by family	NFRC samples on Jada’s site
Sizes	Published per family	Not published
Lead time	7 to 8 weeks to make	Ask

See the steel windows and doors pillar and the slim profile windows guide.

How do I read Bertrand’s numbers?

Bertrand prints Uw and Uf in W/(m²K). A U.S. NFRC label uses Btu units. Masterline 8 shows both: Uw of 0.88 W/m²K is 0.155 Btu/hft²F. Bertrand says it is part of the NFRC Product Certification Program. The U-factor on your label is the number that counts for permits and energy codes. Read the guide to SHGC and U-factor for Texas.

What should you ask before ordering?

• Which family fits my size, and what is the NFRC rating for that window and glass?
• Which finish and color, and what is the finish warranty? Bertrand’s only published warranty is 5 years on Synergic.
• What is the written lead time? Bertrand lists 7 to 8 weeks to make aluminum, plus shipping from Poland.
• Who installs? Bertrand lists no U.S. subsidiary.
• Does my project need security, impact or acoustic classes?

Where do aluminum windows fit in a home?

Aluminum suits modern and transitional homes, large glass openings and renovations that replace old steel windows. Bertrand says SlimLine 38 is “perfectly suited for the renovation of buildings with original steel-framed windows.” Common uses:

• Living areas that want a wide, bright view with slim frames.
• Stairs and tall walls where large sashes are needed.
• Renovations of older steel windows that need better insulation.
• Mixed designs where aluminum fixed units sit beside casements and doors. See casement and awning windows and fixed and picture windows.

Does Bertrand have passive house aluminum windows?

Bertrand lists two systems built for energy-saving design. Its aluminum category page calls Masterline 10 a “Passive House Institute rated system with great stability.” It lists MB 104 as a “modern aluminum system dedicated for energy saving & passive architecture.” We have not read the full data sheets for these two, so ask for the certificates and NFRC data before you plan a passive project.

How do you pick a family?

1. Slimmest sash on an outward opening window: MB-79N CSF.
2. A steel look and size limits: SlimLine 38.
3. Tall casements up to 10 ft: MB-86N.
4. A system rated for Miami Dade NOA: ConceptSystem 77.
5. Three insulation levels: Masterline 8.

Bertrand says it specializes in custom solutions, so ask about sizes outside the table.

Next step

Send us your openings and the look you want. We will match them to a Bertrand family or to steel. See all windows or start your project. Call (214) 484-9982.