Guidance for Specialist Contractors> Curtain Walling

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Specialist Contractors are those companies that supply a complete curtain wall including the glazing and spandrel panels or supply and instal complete windows. In the context of CE Marking these companies are called the Manufacturer of the product and they are responsible for applying the CE Mark.

Window Manufacturers may CE Mark windows by undertaking their own assessments of performance or for simple configurations they may simply follow rules developed by their framing system suppliers.


Curtain wall Manufacturers will probably CE Mark curtain walls by undertaking their own assessments of performance as part of the design process. For the simplest of wall geometries they may follow rules developed by their framing system suppliers.


EN 13830 defines curtain walling as a kit intended to be used as a building envelope to provide weather resistance, safety in use and environmental control. EN 13830 applies to walls with an overall slope that lies between vertical and 150 of vertical

CE marking applies to a 'curtain walling kit'. This is defined as the set of all components required to complete the assembly of the curtain wall at site. For pre-assembled forms of construction a kit comprises the pre-assembled units, glazing, brackets and seals. For site assembled walls a kit comprises all framing members, glazing, spandrel panels, insulation, brackets and seals. Note that CE marking applies whether the kit comprises parts of a system intended for use on many different buildings or custom parts produced for use on a single building.

CE Marking

The Specialist Contractor is responsiblle for CE marking the curtain wall kit to show the performance of the assembled wall as defined in Annex ZA of EN 13830. The performance to be included in the CE mark may be viewed by using the 'performance' button above.

The Specialist Contractor does not attach a CE label to the curtain wall but includes in the project documentation a declaration of the performance and the 'CE' logo as described in Annex ZA of EN 13830. The performance declared should be that of the wall as designed and constructed.

Assessment of performance

The Specialist Contractor may rely on cascading initial type testing:

  • The use of a proprietary framing system allows the specialist contractor to use test results obtained by the system supplier
  • The performance of glass and other components may be taken from CE marking of those products
  • The Specialist Contractor still has responsibility for selecting appropriate components and declaring the overall performance of the wall. Initial Type Testing only applies to constructions that are similar to the initail test in terms of geometry and so forth. Guidance on ITT may be viewed by using the 'Testing' button above.

    Other aspects of performance such as U-value and structural performance have to be calculated by the Specialist Contractor. This may be undertaken using software or look-up charts provided by the component suppliers.

    Windows in curtain walling

    Windows in curtain walling are CE marked in accordance with EN 14351-1. The remainder of the curtain wall and the window / wall interface are CE marked as curtain walling in accordance with EN 13830. This recognises that the fixed parts of the wall will have higher air, water and wind performance than opening windows. Note that other performance such a thermal transmission is consider for the whole wall including windows.

    Some windows are designed specifically for use in a curtain wall and have no integrity without the presence of curtain wall framing members. In this case the window may be tested as part of the curtain wall but the performance of the window should be given independently of the fixed parts of the wall and in accordance with EN 14351-1 Note that the window should still be tested for all performance requirements of EN 14381-1 including operational performance.

    Quality systems

    EN 13830 requires that Specialist Contractors have in place a quality scheme that covers design and manufacture. The Specialist Contractor is allowed to rely on a self-certified quality system. However, independently certified quality schemes in the ISO 9000 series will meet this requirement and may be required by customers.

    Quality schemes should show who makes each design decision and how the decisions are checked.

    Quality schemes should show that all materials and components comply with the project requirements.

    The Specialist Contractor may sub-contract some elements of the work but remains responsible for the performance of the wall and for CE marking.

    EN 13830 requires that 'Personnel performing work affecting the constancy of performance of the product shall be competent on the basis of appropriate education, training, skills and experience for which records shall be maintained.'.

    Duties of the Specialist Contractor

    EN 13830 requires that Specialist Contractors retain project documentation for a period of ten years after the wall is completed. This should include:

  • Design calculations
  • Basis of selecting materials and components
  • Any test reports
  • Documentation showing performance and compliance of any materials and components supplied by others
  • This does not imply that the customer has a right of access to the Specialist Contractor's documentation and they must rely on the CE mark as evidence of performance. However, a customer may make it a condition of a particular contract that test certificates and calculations are made available to the customer.

    In the UK regulation of CE Marking is the responsibility of Trading Standards Bodies. They have a right to inspect project documentation up to ten years from the completion of the project.