Our Systems

Sigma® II

A higher level of prefabrication offering improved levels of assured performance. Our award-winning, BOPAS and BBA approved, closed panel Sigma® II Build System is the robust and effective solution to achieving high levels of fabric performance


Superior performance

The Sigma® II Build System is designed to achieve superior levels of fabric performance, suitable for projects which are seeking to achieve the very highest fabric efficiency standards. With excellent thermal performance and air tightness, the Sigma® II Build System offers reduced material and labour costs by using conventional materials in a more innovative manner.

third party accreditation
STA Structural Timber Association Assure Gold


Our Sigma® II build system is designed to meet the needs of low and medium rise house buildings. It provides our clients with a high performing, high quality, factory-made system that has both BOPAS and BBA third party certification. It is a market leading system that is utilised on large volume housing projects and comes with the options of further enhancements such as factory fitted windows, chipboard clad floor cassettes and insulated roof cassettes. Our Sigma® II build system is only available as a supply and install service to allow us to take full responsibility for the quality and integrity of all site-fitted works.


Fully Insulated
Tried & Tested
Assured Performance
Market Leader


  • Fully insulated closed wall panels
  • Service cavity pre-fitted
  • Built-in air tightness detailing and pre-fitted seals
  • Floor cassettes edge wrapped and insulated
  • Wall U-Values ranging from 0.26 to 0.13
  • Air tightness ranging from 5.0 to 2.0
  • Thermal bridging of 0.04 to 0.02


  • Chipboard or OSB clad factory made roof cassettes
  • Chipboard or OSB clad floor cassettes
  • Roof trusses or pre-insulated cassettes
  • Ground level roof assembly
  • Potential to air test, immediately after kit erection
  • Option to air-test immediately after frame erection
  • Principle service routes preformed in floor cassettes
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Sigma® II Closed Panel Journey

Our award-winning Sigma® II closed panel timber frame system, from manufacture to construction

Related case studies

Bicester Eco Village

Case Study

Bicester Eco Village

September 18, 2020

A2 Dominion’s development in North West Bicester aims to deliver the most sustainable living in the UK for its residents

Saxon Reach, Milton Keynes

Case Study

Saxon Reach, Milton Keynes

September 15, 2020

Saxon Reach, built using our Design Standards of Excellent

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