Sigma® OP3

Open panel solution


This wall type is ideal for very high performance designs, where air tightness less than 3, very low U-values, separate services cavity, air barrier and thinner wall build up are desired.

This system utilises the existing 89mm or 140mm stud options and introduces a separate rigid insulation overlay, dedicated service zone and conventional plasterboard, in combination with fibre insulation between the studs. U-values ranging from 0.26 – 0.15 can be achieved. Typically this would be specified for CSH Level 5, Section 7 gold rated, advanced FEES compliance or Passive Haus Homes.

Sigma® OP3 has the following benefits:

  • Separate air barrier membrane
  • Retains 89 or 140mm studs, for manual or crane erection
  • Limits wall thickness and maintains existing foundation
  • Reduces thermal bridging
  • Provides separate services zone, in front of air barrier
  • Can be air tested before 1st fix, but after weather tight
  • Utilises conventional skills and materials


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Homes For Scotland Home Builders Federation National House-Building Council Royal Institute of British Architects Structural Timber Association Constructionline British Board of Agrement Wood Campus Build Off Site Building Research Establishment WOOD FOR GOOD

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