NBS Source
List your products

This product is no longer available


An exterior load bearing wall system for low-rise buildings which integrates high levels of insulation into its design to deliver an energy efficient solution to the Zero Carbon challenge, whilst keeping wall thickness to a minimum. It is Passivhaus certified and the system achieves a typical U-value of 0.143 W/m²K, making it ideal for projects targeting superior thermal performance or higher levels of the Code for Sustainable Homes.

RockShell is a patented modular system with few components and is delivered to site in ‘kit form’ according to the specified building design. It is constructed from I-shaped steel profiles, encompassed in dense Rockwool insulation and an OSB lining on the inside. It is quick and easy to install and requires no specialist equipment. By manufacturing the system to an exact specification, RockShell offers increased air tightness performance and minimizes thermal bridges when compared to traditional building methods. The potential integration with many common building components and choice of external finishes offers maximum flexibility in building design. The system is suitable for buildings up to two and a half storeys and with most types of foundation.

Features and benefits:

  • Good acoustic properties.
  • Excellent fire resistance properties.
  • Flexibility of exterior finish.
  • Increased air tightness.
  • Interfaces with most standard building components.
  • Low installation costs.
  • Minimal on-site waste.
  • Minimizes thermal bridging.
  • Reduces installation risks.
  • Suitable for use in Low Energy and Passivhaus buildings.

General information
Specification data - Light steel wall framing systems
Product Reference

RockShell Wall System®

Standard product features

Total wall thickness:

364.5 mm.

Technical properties:

  • Fire rating (from inside/ outside): REI 60/ 90 minutes.
  • Load bearing capacity per profile (2.7 m height): 53.3 kN.
  • Sound reduction (minimum): 54 dB.
  • U-value (typical): 0.143 W/m²K.

Product Options


The amount of components required is dependent on the individual design requirements.

– Bottom profiles:

Mounted securely on the concrete foundation on a layer of bituminous roofing felt adhered to the foundation with cold asphalt sealant. Bottom profiles are used to fix the wall to the foundation and brackets are used to fix the wall modules.

– Steel I-beam profiles:

Create a light steel frame on to which the wall modules are secured. Fixed to the bottom profiles at foundation level.

– Wall modules:

289 mm thick, 600 mm wide and up to 2700 mm high Rockwool insulation. They feature unique slits on all four sides to make them fit perfectly into the flanges of the steel profiles. A further steel profile is mounted on top of the modules and fastened to the profiles. Finally a laminated veneer lumber board is placed upon the top profile to complete the wall section.

– End columns and lintels:

For framing openings of windows and doors.

– Corner insulation elements:

Set slantwise in position to finish corner details, featuring slits to fit into the steel.

– Laminated nailers:

Mounted onto the external face of the wall modules to cover and tighten joints between the RockShell wool elements, establish a ventilated cavity and create a secure mounting for the chosen external finish.

– OSB boards:

Mounted directly onto the interior face of the wall modules to create a secure mounting for the service wall and interior linings.