Guidance for technical authors in relation to carbon impact of Requirements and Advice Documents (RADs)

 

Introduction

This guidance note has been produced for the technical authors of Requirements and Advice Documents (RADs) who are drafting documents and also required to complete Sections 1.3 and 2.3 (Impact on carbon, sustainable development and good design) of the impact assessment report and undertake a comprehensive assessment of the benefits and drawbacks of any carbon-related amendments to RADs. This is applicable to anyone updating existing or new RADs.  

RADs can support carbon reductions in two main ways:

  • Giving greater flexibility to designers and contractors about the materials, methods and processes used on projects and renewals, allowing low carbon alternatives to be employed. 
  • Giving confidence to designers and contractors (as appropriate) that new, low carbon alternative products, materials and tools are safe and effective. 

Background – How do Requirements and Advice Documents (RADs) influence carbon emissions?

RADs are fundamental to the delivery of high-quality construction and maintenance projects on the strategic road network. They are the benchmark of good design, and directly impact quality, safety, efficiency, and cost.

As RADs are continuously improved, technical authors are required to incorporate a range of additional considerations that drive best practice across the industry. One of these considerations is the reduction of carbon emissions from highways infrastructure, which accounts for more than 10% of UK emissions.  

The National Highways Net Zero Plan commits us to reducing carbon emissions to net zero by 2050.

For construction and maintenance activities, which the majority of RADs are applicable to, the target is to be net zero by 2040.

In addition, GG 103 requires the minimisation of greenhouse gas emissions associated with the whole life of a project.  

Back to top

Guidance – Drafting Requirements and Advice Documents (RADs)

RADs should be developed in accordance with the Manual for Development of Documents (MDD). Part 3 Section 14 covers Carbon Management, sustainable development with guidance presented therein.

Some specific considerations and examples are presented below to further support the technical author in updating a RAD.

When updating RADs, authors should not preclude low carbon solutions from being used in place of traditional materials or technologies through restrictive language. For example:

  • [Taken from CD 169] A new section permitting the provision of observation platforms will not specify any products or materials and it be will up to designers and contractors to specify lower carbon, longer life materials and sustainable construction process on a site by site basis.
  • [Taken from CD 146]: A RAD allows there to be flexibility to co-locate two or more VMS together, which will help to reduce the amount of carbon associated with the use of the VMS/signals. 
  • A RAD allows for the application of modern methods of construction (such as offsite manufacture), which typically have a lower carbon footprint than traditional methods.  

Authors should determine whether there is an opportunity to update the language used in RADs or include decision-making pathways that support the adoption of low carbon alternatives. 

  • For example, instead of specifying that structural beams must be a certain thickness, the RADs could instead specify that the beam thickness must be proven to withstand x amount of load. This allows for greater flexibility for lower carbon solutions (such as reuse of existing beams or greater recycled content) to be employed that achieve the same outcomes, without compromising safety or quality.

Where a RAD relates to a decision-making process or methodology, this could be amended to include a broader reference to the carbon reduction hierarchy.  

Technical authors may consult with the National Highways Central Carbon Team for further guidance and support on specific queries during drafting.

Back to top

Guidance – Completing the Impact assessment

The Impact Assessment Report comprises 2 sections related to carbon impact with embedded guidance. 

  • Screening – to determine whether an assessment is necessary for the document.
  • Full Assessment – A series of questions to capture the consideration of the carbon impact.  

Some specific considerations and examples are presented below to support the technical author in updating a RAD and completing the assessment.

  • Low carbon alternatives should be assessed against risk factors including safety, longevity and cost. Technical authors shall present such risks in the impact assessment and identify who should be consulted to gain feedback whether or not these risks are acceptable and engage them as appropriate. 

Technical authors may consult with the National Highways Central Carbon Team for further guidance and support on specific queries during the development of the impact assessment report.

Back to top