The embodied CO2 module will give clients feedback as the energy model is being built. The software shows embodied and operational combined, as it can be easy to focus on embodied CO2 calculations when very often it is operational CO2 that dominates. 

PHribbon calculates Whole Life Carbon, that is Embodied CO2 from Cradle to Grave, covering stages A-C (and D where information is available). It is suitable for initial estimates for the RIBA 2030 Challenge v2 and LETI. This therefore includes :

Stage A, A1-A3 Manufacture including A4 Transport to site and A5 Construction
Stage B, Use of the building including B4 Replacement
Stage C, Demolition and Disposal of the building
And quoted separately Stage D, Reuse, Recycling potential (outside the usual scope of the main calculation). It calculates the credit from reuse of an element, assembled part such as a frame, or something that is reused offsite.

There are 2 UK versions of the AECB Embodied CO2 calculator, they look very similar and have exactly the same calculation. One is part of the PHribbon package and links in with PHPP. The other is a stand-alone calculator that works independently – this looks very similar, but doesn’t produce the combined Embodied and Operation graph.

Input Data

  • built-in library of 291 entries from EPDs containing the Full Life info for stages A-D and a further 140 from ICE 2019 with manufacturing data (A1-A3)
  • includes CO2 stored in timber and timber based materials, also called sequestered CO2. This is calculated where it has been omitted in the EPD.
  • standard RICS methodology including 60 year Reference Study Period
  • filters EPDs, choose whether you want to see products manufactured within your country, a region e.g. Europe, or all the EPDs
  • [PHribbon version only] matches materials automatically, you only need adjust the choice where necessary, you can now also see both the original material and the material it was matched with, in case there is a difference
  • [PHribbon version only] remembers associations you make between phrases in the PHPP and materials
  • density, this is given by the software, but you can change it where units are “kg” in the final output sheet, for example if you know the installed density of cellulose or blown mineral wool



  • coloured results, the output table is coloured by value to make it easy to see where the CO2 is coming from
  • fully transparent calculation
  • up to 4 options can be graphed/compared
  • simpler format and option to simplify further so only the names of the materials and results are shown
  • Scope Summary written below the calculation for you to keep a record of exactly what is included
  • RIBA results gives RIBA 2030 Challenge results and gives data in the format for RIBA awards applications
  • [PHribbon version only] Total CO2 graph shows operational and embodied CO2 over 60 years (Button also to extend this >60 years)
  • [PHribbon version only] AECB Assessment summary that is printable
  • LETI results graphic and detailed tables, all laid out on printable pages

Results are also given by each stage for each material. The automatic colouring makes it easy to spot what material is contributing most and at what stage:

The graph below left shows the Embodied CO2 of up to 4 options.  Below right is the combined Embodied and Operational CO2 using the data calculated in PHPP.  (Graphs normally show a maximum of 4 options, here the one on the right has been manually customised to show 5).

RIBA and LETI results are shown in the LETI format and allow for slight measurement differences: