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Green Glazing Calculator GGC

Create Greener Glazing

Secondary Element Calculator Sheet 3 Bespoke B13 Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGS

Green Glazing Calculator GGC


  • We are supporting manufacturers to consider development of GGC design and decision tool
  • GGC’s emphasis is on carbon counting and will also  address chemistry counting
  • If funding is gained GGC core will be substantially developed within 3-6 months
  • The greater task will be gathering datasets for many materials and products
  • Once complete the same developments in GGC will be applied to GBC & GRC tools as soon as we can.

Proposal for GGC Green Glass Calculator Design & Decision tool

Based on parts of GBC Green Building Calculator with further developments

Green Building Calculator GBC suite of tools started life as 2 calculators to teach 5th year architecture students about:

Form-factor to help set targets, U value calculations, embodied energy and carbon and in-use energy and carbon calculations;

To analyse their studio designs (any building(s) type or shape).

GBC Development:

Covid gave an opportunity to merge these 2 calculators and add more functionality:

Bill of Quantities, Costs, pay back and carbon back periods, many elements of construction, one or many sized windows, etc.

GBC Competency:

In the absence of competent architectural education (only awareness has been required until Grenfell fire)

GBC is trying to be a design and decision tool to fill the education gap and tackle the performance gap

GBC includes links into advisory pages of GBE Green Building Encyclopaedia to:

Jargon Busters, Checklists, Q&A, Brainstorms, Issue papers, etc. and further afield.

GBC users & potential GGC Users:

GBC Green Building Calculator was developed with small practices with small software budgets in mind.

(the majority of the architectural profession, technicians, technologists, surveyors)

These practices may not be using IES, SAP or SBEM, often reliant upon external consultants to offer these services.

GBC Green Building suite of design and decision tool calculators:

GBC (buildings), GRC (Retrofit), GIC (Interiors), GSC (Screeds), GGS (Glazing), GIRC (Insurance Repair)

Are in various stages of development

Are intended to offer a degree of autonomy to micro-SMEs practices:

to improve their understanding of their outputs

an opportunity to broaden their service.

increase in-house skills.

increase in-house capacity.

GBC could even be used by manufacturers/suppliers in-house as a specification advisory tool/service.


GBC is BIM Building Information Management

without the Building Information Modelling

(Words and numbers without the CAD computer aided design)

GBC is built upon MS Excel:

There are many interlinked worksheets

‘Accommodation Schedule’ worksheet:

GBE Green Building Calculator ScheduleAccommodation A15 BRM 280520 PNG

Collects dimensional and numerical building data, hours of operation (hours of temperature control), temperature inside and out

Works out areas and volumes, including multiple rooms of the same or different sizes

Room by room calculations including walls, floors, roof, windows, doors and rooflights

Addresses single or multiple sized windows for commercial or residential buildings

‘Form Factor’ worksheet:

Helps to understand the need to consider the volume to surface area ratios of the building

to help set target U values to achieve a low energy demand building

Addresses special additional geometry of porches, conservatories, dormers, oriels and bays

Targets worksheet:

To support U value & Embodied Carbon calculations: GBC includes:

Target U values from regulations, design standards and campaign targets

Permits adding any national or project targets,

Users can instantaneously switch between them.

Assembles and compares permitted values with conditional formatting to visually show best and worst

‘Elements’ worksheet:

Alongside 39 readymade building elements

GBC has 12 different readymade glazed elemental assemblies.

GBE Green Building Calculator Building Elements A13 BRM 250520 PNG

All of which can receive product specific whole element U values or

numerous components (materials or products) to work out the U values.

These currently include:

  • U value, BofQ, EEECSC
  • EMD (materials) or EPD (products) to EED (elements) and EBD (Building) calculations.
  • Could be added to with: Daylight factor, Solar heat gain, G values, etc.
  • Also includes for opaque building fabric: Condensation check, Decrement Delay

Green Building Calculator GBC Elements EE EC SC V2 230422

There is scope for adding internal glazed partitioning with acoustic and/or fire performance.

‘SecondaryElementsCosts’ worksheet:

Secondary Element Calculator Sheet 1 Bespoke B13 Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGS Secondary Element Calculator Sheet 2 Bespoke B13 Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGS Secondary Element Calculator Sheet 3 Bespoke B13 Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGS Secondary Element Calculator Sheet 4 Bespoke B13 Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGSSecondary Element Calculator Sheet 5 Bespoke B13 Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGS

Is part of the GBC Green Building Calculator and it needs further development and refinement.

It could become autonomous and renamed GGC Green Glazing Calculator

It shall also remain an integral part of GBC

It was created to reduce glazing assemblies down to all component parts.

Including single, double, triple or multiple glazed sealed units, laminated glasses, etc.

Includes all the components of a window/door/rooflight frame so that any permutation of glazing can be calculated.

It collects glass specification choices, windows sizes, frame and bead materials and profiles, orientation,

It collects or calculates Ug & Uf data inputs and Uf and Uw calculation outputs.

It calculates solar heat gains, internal to external heat losses and net heat gain or loss

Can address Internal and external glazing, mirrors, balustrades and furniture

‘Look up table’ worksheet:

GGC has a Look up table of glazing materials and products, framing materials and products with their respective properties

that feed the glazed elemental calculators mentioned above.

GBC includes BAU datasets, from many standards and other datasets from sources including ICE and EPD.

‘EEECSC’ worksheet:

GBC EEECSC Datasets V2 280322 PNG

Embodied Energy, Embodied Carbon & Sequestered Carbon datasets of materials

Is a look up table to feed the calculations

Includes: ICE 1,2 & 3 and other datasets

LCA EPD worksheet:

Sets of data extracted from EPD Environmental Product Declarations for products and generic materials

Reformatted from tables to single rows

Green Building Product Data Collection (GBPDC):

GBC GBPDC Man Supplier Form V2 290521

Is intended to address post-Grenfell competencies by collecting manufacturer’s intended primary function, location and application as well as properties and performance for the calculations.

GBPDC feeds GGC once we start collecting that data too.

Currently GBC’s ‘SecondaryElementCosts’ worksheet includes a small selection of product data,

sufficient to build and test the calculations.

GBC also has access to Fire Resistant Glass and multiple skin plastics glazing datasets from GBC Robust specifications

GBC GBPDC Man Supplier Form V2 290521

Green Building Product Data Collection GBPDC collects:

  • what is the primary and/or secondary functions of the products,
  • where was it invented to be used in the building,
  • where in the element, inside middle outside,
  • physical properties,
  • performance characteristics,
  • impacts,
  • certification and test evidence,
  • MSDS,
  • EPD datasets.

GBC has collected limited generic data and some product data that was easily available on Single D&TGSU in order to create and test the calculator.

‘Drop Down Lists’ worksheet:

Bespoke B13 Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGS

The look up table can be connected into those elemental assemblies via many short bespoke drop down lists;

Short lists to only offer appropriate competent materials but also introduce new to you options.

Choose any item and the adjacent cells will be populated with materials or product specific data to run the calculations.

Bill of Quantities worksheet:

GBE Green Building Calculator Elements BofM QTRC A13 BRM 210520 PNG

There is a built in Bill of Quantities that allow the users to populate cells to monitor costs

Green Building Price Book GBPB

GBPB to feed the BofQ once we start collecting that data too.

GBC Summary worksheets:

GBE Green Building Calculator Elements Summary A13 BRM 210520 PNG

Bring many calculation results together in one place to allow comparison of results in different scenarios

Any change anywhere in the worksheets will provide instantaneous results in the summary sheets.

Subdivision of elements with % of areas and % of heat losses allow comparison and encourage review of some specifications.

Having all this information on one place at the same time means true Value Engineering can be considered avoiding cost cutting

GBC Users

GBC is already being used by Architects, graduates, students, professors, contractor, developer, training centre, charity, self-builders, unidentified others; in or from UK, EU and International.

The Suite of calculators

GBC (Building) works for any building type, for new build.

GRC (Retrofit) is pre-populated with residential data but any building use can be added by users via the tablet survey worksheet

GIC (Interiors) will start with a domestic function, but it is obvious this will grow to do any other building later.

GIC Green Interior Calculator Logo by NGS ltd. BrianSpecMan

GIC will need to include glazed internal partitions, screens, furniture, etc.

GGC developments can be added to GIC

Green Glazing Calculator GGC part of the suite of Green Building Calculators by BrianSpecMan of NGS Ltd.

GBC addresses winter heat loss and summer heat gain through thermal insulation materials options,

Specific Heat capacity, k value conductivity, Density, Decrement Delay.

GGC Green Glazing Calculator does address glazing orientation and summer heat gains.

GBC Adoption

Any user could adopt GBC GRC, GIC or GGC to calculate their own impacts.

This includes contractors with or without CDP Contractors Design Portion contracts: e.g. D&B, CM. MC, etc.

If the post-Grenfell regulation tsunami permits these procurement methods in future.

GBC suite can become part of any specification substitution process to instantaneously monitor all input and output changes with any materials or products swaps.

Once a building is designed and embedded in GBC the files can be handed to the contractor to do any Value engineering as opposed to cost cutting and monitor Carbon impacts Embodied and in use WLCO2)

GBC collects and/or calculates whole building dimensions and quantities, form factor, U value targets, scope of elements, component materials and thicknesses, U value pass or fail, embodied energy, embodied carbon sequestered carbon, initial costs, running costs, pay back periods, carbon back periods, whole life energy and carbon.

Frameless glass:

If the glass is a frameless window: many frame cells will be set at 0

If the assembly is a structural glass assembly SGA with metal supports there is no frame that needs to be included.

(SGA are not modelled yet)

Other Glass applications:

GIC and GGC will have mirrors, shower screens, room division, glass in furniture, glass balustrades and stairs, etc.

GGC must collect and emphasise low impact product data over generic or poor performance products.

And if a manufacturer is ahead of the game all their glasses could outshine the competition.

Competitors’ or generic glasses would need to be included for comparison purposes.

Whilst GBC and GGC as they stand do not address all of the issues yet, with manufacturer’s in-house expertise it/they could be developed to do so.

GIRC Green Insurance Repair Calculator:

GIRC will be tackling Main and Subcontractor impacts of transport of materials staff and plant and embodied impacts to damaged materials out and new materials in, waste and costs.

Worksheets are modular:

All parts or calculators are modular and can be copied between calculators.

All benefits in GGC could be applied to the whole GBE suite of tools and visa versa.

Funding development:

I could envisage partnering in an Innovate UK grant application to develop an ASAD glazing calculator with all of a manufacturers internal expertise to help make GGC as robust as possible.

I would suggest Manufacturer be lead partner.

Innovative Solution to an Industry Challenge

  • The environmental impact of glazing specification can be significantly higher than the opaque elements of the building due to their U values and potentially shorter life cycles.
  • With an urgency to address global carbon we are increasingly seeing manufacturers providing Life Cycle Assessments (LCA) and Environmental Product Declarations (EPD) of materials including Energy, Carbon and other impact data of those materials.
  • There are significant amounts of product data available in manufacturers’ literature and Materials Safety Data Sheets (MSDS) but very little is done with this data.
  • GGC will extract this information, analysing and processing it to make it comparable across different products and scenarios.
  • This goes far beyond carbon counting, comparing data across a vast range of environmental and health metrics.
  • GGC will enable designers to compare and evaluate their design and specification choices, providing evidence-based solutions that meet specific client’s preferences for environmental and healthy buildings.

New Revenue Stream

  • GGC builds on NGS’s already powerful Green Building Calculator (GBC) and Green Retrofit Calculator (GRC) to build a new tool for a new market.
  • GGC Green Glazing Calculator delivers a significantly more powerful user-friendly design and decision tool with markedly more detailed analysis of embodied impacts of material choices.
  • Learnings from developing GGC will be applied to improvement of GBC and GRC increasing sales of the whole suite of tools.

Market Readiness

  • Building on existing technology and working closely with user representatives means we can develop this solution rapidly, ensuring it meets the needs of the market.
  • Following this project we intend to progress quickly, piloting the technology with our user representatives and launching to the wider market within 12 months.


  • Building on 4 years of development (GBC and GRC), GGC can be developed at low cost.

Supporting Datasets

  • In order for GGC to become and remain vital we have planned a number of websites to serve users of and automatically feed GBC, GRC & GGC:

Green Building Product Data Collection

GBPDC Green Building Product Data Collection Logo

  • GBPDC will include:
    • Manufacturer, product, system and application dataset
    • Product purpose, materials, properties and performances datasets
      • Sufficient for an outline specification
      • Potentially a full specification
      • Some of a Product/Materials Passport
    • Environmental Product Declaration dataset
    • Material Safety Data Sheet dataset
    • To feed the calculations

GBC GBPDC Man Supplier Form V2 290521

Green Building Price Book

Green Building Price Book GBPB logo part of a suite of tools supporting Green Building Calculator, Green Retrofit Calculator, Green Interiors Calculator all by BrianSpecMan at NGS Ltd.

  • Will collect price data, but the challenge will always be:
  • how many do you want?
  • what discount is the worth?
  • GBPB will collect prices for:
    • 1 m2, 10 m2, 100 m2, etc. (product or installation)
    • 1 m3, 10 m3, 100 m3, etc.
    • 1 pallets full, 10 pallets full, etc.
    • 1 unopened unsplit pack, 10 , 100, etc.
    • Waste removal by skip sizes, waste categories
  • Avoiding ‘your best possible price’ which is unobtainable by most
  • Avoiding the downwards spiral of specification substitution and increasing performance gap
  • GBPB will seek cost data from:
    • Suppliers
    • Manufacturers
    • Installers (approved or trained by manufacturer or supplier)
    • Licenced Waste Handlers
  • Deconstruction and Demolition is too bespoke to get cost data
    • But as a suggestion:
    • Give them 1 month to demolish they will charge you
    • Give them 3 months to deconstruct they will pay you

Green Building Robust Specification

GBS Green Building Specification, Robust Specification Logo

Green Building Robust Specification GBRS logo part of a suite of tools supporting Green Building Calculator, Green Retrofit Calculator, Green Interiors Calculator all by BrianSpecMan at NGS Ltd.

GGC will also collect and generate an outline specification for materials or products used

GGC may also collect and generate a full specification

Green Building Facilities Management Specification

Green Building Facilities Management Specification by BrianSpecMan at NGS Ltd.

Green Building Materials Product Passport

Green Building Materials Passport GBMP logo part of a suite of tools supporting Green Building Calculator, Green Retrofit Calculator, Green Interiors Calculator all by BrianSpecMan at NGS Ltd.

GIC will also collect and generate some of the information needed for a Materials Passport

Green Building Method Statement

Green Building Method Statement GBMS logo part of a suite of tools supporting Green Building Calculator, Green Retrofit Calculator, Green Interiors Calculator all by BrianSpecMan at NGS Ltd.

© GBE GBC GRC GIC GBL NGS ASWS Brian Murphy aka BrianSpecMan *****
15th March 2024 – 16th March 2024

Green Glazing Calculator GGC


Green Glazing Calculator (GGC) includes many features:

  • GGC is a multi-functional design and decision tool that also counts carbon
  • GGC has been developed from Green Retrofit Calculator GRC V1
  • GRC has in turn been developed from Green Building Calculator GBC V1&V2

Component calculators

  • Tables of insulation materials, formats, densities, conductivity and decrement delay values; having set targets then thicknesses of each materials are displayed for each element

  • Collection sheet where data is added and choices made, trigger cells being populated from look-up-tables
    • Cells are populated from: survey, others from look-up-table, some user-added
    • Materials choices are filtered offering only competent materials in each cell (Golden Thread)
    • Materials offered include conventional, unfamiliar low carbon, low impact alternatives

GBE Green Building Calculator Elements U values Basement A15 BRM 280620 PNG

  • Bill of Quantities for cost planning, sub-contract tender collating, tendering, value engineering or cost cutting

GBC Bill of Materials Quants Costs V2 A24 BRM 260122 PNG

  • Embodied Energy, Embodied Carbon, Sequestered Carbon based on interiors materials previously chosen

Green Building Calculator GBC Elements EE EC SC V2 230422




User Interface Experience:

We will develop the GGC interface for users,

  • we envisage a question and answers mechanism to populate cells and choose from options
  • but the steering group will guide us on what is needed and how to do it.

This will interface between the user and the core MS Excel number crunching.

GGC is based on MS Excel and has many interlinked worksheets, up to now we have used colour coding of cell types so users know what to do in each cell, row, column or block:

  • Green cells: require text or numerical data adding
  • Blue cells: deliver results of calculations, based on green cell information
  • Turquoise: cells deliver results of calculations, but can be overwritten to add variables
  • Red cells: require the user to choose from drop down lists (preventing typing or spelling errors, keeping cells functional)
  • Brown cells: deliver data from look-up-tables triggered by choices in red cells or concatenation of blue cells
  • Violet cells: users to review and make judgments and return to previous decisions for any necessary improvements
  • Conditional Formatted cells: inform of pass or fail meeting targets, high or low, good or bad results
  • Instructions are being added as pop-up comments, short videos explain purpose of worksheets and how to edit them.

GBC CellColourCodes V2 280322 PNG


GIC is intended to initially serve non-BIMers

  • Provide Building Information Management (BIM) without Computer Aided Drawing,
  • Since 30% users have no need for BIM
  • When GGC is developed into a BIM App
    • Green cells can be populated from BIM Bill of Materials (BOM) or dimensional information from CAD model
  • APIs will be developed
  • Algorithms will be explored

Customer Satisfaction:

  • I first encountered Brian Murphy and calculators that became GBC/GRC, at university in my masters program in 2016 and was quite impressed with them.
  • We were able to see very clearly the impact of our design solutions by using the calculators.
  • More importantly I saw what it could provide, a direct antidote to green washing.
  • In the private residential market, typically these projects have small design teams and discussions about what is the best solutions are, become a debate between contractor and architect, often the clients choose to go with contractor’s suggestion.
  • GBC/GRC provides a much more robust argument with which to convince client and contractor.
  • One client was happy to follow guidance from GBC/GRC, main contractor was mostly supportive, but sub-contractors continually challenged our decisions and at every opportunity pointed out to the client that the amount of insulation was not necessary.
  • GBC/GRC gives the client the confidence to ignore the noise coming from them.
  • Once project data is in GBC/GRC you can really examine the design, carbon and cost implications between different types of insulation for example.
  • GBC/GRC openly identifies where information is coming from how it’s being used so as to be transparent.
  • Bryan Strom, Slab Architects, London

Bryan Strom GBC user

Technical support:

  • GGC is not yet created, nor launched,
  • We have established Calendly call booking for phone, zoom or face to face meetings & CPD

GBC Calendly Options

  • We have plans to establish User, Steering and Development groups as soon as possible.
  • We collect feedback and add them to the Revisions Pending list

Data Management:

  • GBC/GRC both have audit trails built into every row and column of the worksheets,
    • Initial and dates added to all actions
    • Extensive revision table records sequence of development all proposal and when completed
    • Any partially completed task is recorded to ensure completion in due course

© GBE GBC GRC GIC GBL NGS ASWS Brian Murphy aka BrianSpecMan *****
15th March 2024 – 16th March 2024

Green Glazing Calculator GGC C#2189 End.

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