Why is steel frame the best ally for insulation?

At beSteel, we believe building better also means living better. Whether you’re planning a new home or upgrading an existing one, insulation is key to energy efficiency, comfort, and health. But how can you achieve top insulation performance without sacrificing space or design freedom?

The answer: lightweight steel frame construction.

Why is steel frame ideal for insulation?

Thanks to its structure and flexibility, steel framing opens the door to high-performance thermal and acoustic insulation solutions, while allowing thinner walls, modern architecture, and long-term durability. Let’s dive into the details.

1. More living space thanks to thinner walls

Steel frame profiles are extremely compact and precise. At beSteel, our profiles vary from 50 mm to 250 mm, allowing you to build thinner walls without compromising insulation.

• Compared to traditional brick or concrete walls, a steel frame wall can save up to 10 cm in thickness.
• That means more usable living space — a major value driver, especially in cities where every square metre counts.

“This is one of the reasons many real estate developers choose lightweight steel,” says Hélène de Troostembergh, founder of beSteel. “In Brussels, Paris or Amsterdam, gaining even a few extra square metres is a clear financial benefit.”

2. No thermal bridges 

In a well-designed steel frame wall, insulation is placed on the outside of the structure, completely covering the cold-conducting metal. This method eliminates thermal bridges, which are weak points where heat escapes and condensation forms.

This technique allows:

• Better thermal performance and thus lower U-values
• Reduced risk of mould or internal condensation
• Compatibility with passive house and NZEB building standards

3. Healthier indoor climate

Because the steel structure sits on the warm side of the insulation layer, it maintains a stable internal temperature. There’s no contact between warmair and cold metal, which removes condensation risk.

By combining:

• external thermal insulation,
• internal insulation between studs,
• and vapor or airtight membranes or sheating.

You get a wall system that ensures a warm, breathable, and healthy environment all year long.

4. Creative freedom, endless façade options

Steel frame construction adapts to any exterior finish:

• Brick cladding
• Timber cladding façades
• Rendered surfaces
• Metal, fibber cement, or composite panels

The insulation is installed independently of the aesthetic layer, so you can focus on both performance & beauty.

What insulation materials work best with steel framing?

A combination of internal and external layers ensures the best results.

1. Between the steel studs:

• Wood, hemp or grass fibre insulation (bio based, and have a great inertia)
• Cellulose fibres (Circular insulation, and great ease of installation)
• Mineral wool (glass or stonewool)

These provide excellent acoustic and thermal insulation, and fit easily between the metal profiles. Biobased insulation often have a better thermal inertia, also protection better against overheating in the summer, and off cours the climate but also indoor air quality benefits from it.

2. On the outside:

• Wood, Hemp or Gras fibre mats
• Mineral wools
• For ventilated facades it’s easiest to work with rigid boards like wood fibre, or offcourse PUR, PIR, EPS, XPS.
• Also for Etics (plaster facades) is possible to work with wood Fibre, or EPS

With this approach, you get a continuous insulation layer and achieve U-values more then compliant with EPB (Belgian Energy Performance) regulations.

Want to know more?

Let’s build smarter, more efficient homes — together.

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