Skip to main content

Manufacturer Supplier Letter

Dear Manufacturers, Suppliers and DataSet Providers

Welcome to Green Building Calculator (GBC)

  • I hope you will have already attended a Zoom meeting to address this GBC’s Green Building Product Data Collection (GBPDC) and Green Building Price Book (GBPB) tasks.
  • Or you may have attended FutureBuild 2022 exhibition launch GBC are aware that there are many U value calculators out there but most are by individual manufacturers and inevitably they are designed to sell more of their own stuff.
  • In the absence of comprehensive data for a diverse range of products out there these calculators help to maintain business as usual (BAU) GBC originally created 2 calculators for RIBA Part 2 Architectural students who would be out there choosing and specifying materials in a year or two.
  • It turned out that all the part-time students took the calculators to their office and used it on real live projects.
  • During Covid Lockdowns GBC developed a multi-functional version of the 2 merged calculators to engage robustly with Climate Emergency and provide a tool for all building designers to join in.
  • There is a lot to be said for putting product information in front of students, Metza have put loads of samples into Uni workshops to great effect.
  • GBC wants this calculator to be as comprehensive as possible populated with real building products and materials with a full set of product data and costs.
  • GBC is now updated and expanded for professional use and is available online:

Version 1 (created during COVID 1st lockdown) already addresses:

  • New Build
  • Whole building areas and volumes
  • Elemental areas and component volumes
  • Form Factors (to help guide the R or U value targets)
  • Regulations and Design Standards to choose Targets R and U values
  • Elemental Assemblies (to address thermal bridges and work out R or U values and engage the many other parts of the calculator)
  • Components parts: (with function, material choice and thicknesses)
  • Materials datasets with an emphasis on Bio-based construction (part of the Climate Emergency solution)
  • Room by Room Heating demands (for radiator and underfloor heating UFH manifold sizing)
  • Energy Source Sizing (or insulating to match energy source)
  • Whole building energy demands Elemental breakdowns
  • Element area % v element heat loss % (allows real value engineering (VE) discussions with the client)
  • Fuel choice carbon factors Carbon In use (part of the Climate Emergency discussion)
  • Compare cost and performance of insulation and windows (real VE)
  • And other features

GBC Version 1 is being updated now to GBC Version 2 addressing:

  • Updates to many of Version 1 worksheets
  • Retrofit Specifics developed (for one off or community scale projects, historic fabric features added)
  • Bill of materials, Accessories, Quantities, Labour, Costs (For Cost planning, price gathering and tendering)
  • Embodied energy and carbon (Engaging with Climate Emergency)
  • Sequestered carbon (Emphasising Bio-based construction advantages)
  • Fuel choice costs
  • Cost in use (adding to the VE discussions)

It is being updated Version 3 to 35 over the following months and years with more datasets and more functionality addressing:

  • Life Cycle Assessment (LCA) (Engaging with Climate Emergency) and Environmental Building Declaration (EBD)
  • Competent Construction (Post-Grenfell avoiding permitting products being used incorrectly)
  • Condensation Check (Avoiding incompetent assemblies)
  • Decrement delay calculation (Avoiding overheating)
  • Readymade Elemental Assemblies, Manufacturer’s Competent solutions and Bespoke Elemental Assemblies (892 readymade, manufacturers and users contributing their own)
  • Waste Cost and Embodied Carbon calculator (to encourage waste segregation and cost savings)
  • Plastics content and plastics avoidance (removing fire hazards and reducing opportunities for microplastics at large)
  • Recycled Content Products Circular economy, (Reclaim and Reuse, Recovery, Recycling)
  • Multi-purpose Multi-functionality and Value Engineering 
  • Green Building Price Book (GBPB) (20 years after it was first suggested)
  • Computer Aided Design (CAD) Building Information Modelling (BIM) Application (to speed up the population of the MS Excel cells and creating BIM Models from calculator)
  • And much more

GBC will continue to develop the calculator after this current update if you are unable to respond to this request immediately, your information will always be welcome for later additions

GBC has put GBC Green Building Calculator V1 into the public domain for general consumption.

V2 is to follow shortly.

GBC Links

  • If your products do not fit into this spreadsheet, let us know which other columns need adding.
  • If your products do fit please complete this as soon as possible, this week would be nice, within 3 weeks to make the next Version release, later still will still be useful.
  • If you cannot help immediately but will later, do let GBC know.
  • If your product needs more columns please add them to the right of the existing or add notes in the comment column.  

  • You’re help in this matter will be much appreciated and acknowledged and we hope it will generate more real enquiries for your products
  • Good luck with filling in the table We have added a legend to explain the meaning of the cell colours
  • GBC has also drop down lists to prompt you with the potential information to add and to maintain a degree of consistency, avoid typos and engage other calculator functions
  • Thank you for your time and patience.
  • If you need help do not hesitate to call me


Brian Murphy ONC HNC Construction, BSc (Hons) PGDip (Dist) Architecture aka BrianSpecMan

© GBE GBC GBL NGS ASWS Brian Murphy aka BrianSpecMan **
29th September 2020 – 13th March 2022

Close Menu