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Green Interior Calculator GIC

Create Greener Healthier Interiors

GIC Green Interior Calculator Logo by NGS ltd. BrianSpecMan
GIC Green Interior Calculator Schematic one of a suite of GBC Green Building Calculators by BrianSpecMan of National Green Specification

Green Interior Calculator GIC


  • We are seeking funding to develop GIC design and decision tool
  • GIC’s emphasis is on carbon counting and chemistry counting
  • Whenever GIC proposal is mentioned to others there is an immediate positive response
  • If funding is gained GIC core will be substantially developed within 6 months
  • The greater task will be gathering datasets for many materials and products
  • Once complete the same developments in GIC will be applied to GBC & GRC tools as soon as we can.

The big challenges and opportunities:

  • UK Planning applications for home improvements increased by 52% in 2021 compared to the previous year,
    • suggesting the market for renovations is strong (UK-Planning-Portal, 2021).
  • 63% of homeowners plan to make improvements over the next ten years (Halifax, 2022).
  • 25% hire interior designers (Houzz&Home, 2023),
  • equivalent to an estimated 282,000 projects/year that would benefit from a solution.
  • Residential properties account for 17-21% of energy related carbon emissions globally (UN, 2021).
  • In the UK, households contribute up to 40% of total emissions (includes energy/transport/waste/etc), with the average home emitting 2.7 tonnes/year CO2 from heating alone (Climate Change Committee, 2021).
  • By incorporating eco-friendly choices at design level, people have the potential to reduce energy bills and emissions by up to 30% (Green-Business-Bureau, 2022).

The individual behaviour change opportunity and challenge:

  •  66% of home buyers actively seek out properties with eco-friendly features (insulation/renewable energy/etc) (LRG Research, 2021).
  • 75% of British adults are worried about climate change (ONS, 2021).
  • 81% have made some lifestyle changes to help tackle it (ONS, 2021).
  • However, 55% of people say they lack information/guidance on how to help (Kantar-Public, 2021).

Sustainable Furnishings Council’s (SFC)

  • 2018 Green Home Furnishings Consumer Study
  • 92% of respondents expressed interest in purchasing environmentally safe home furnishings if style and cost considerations were comparable.
  • Nearly 60% of respondents are willing to pay 5 to 10 percent more for home furnishings certified to be environmentally safe.
  • 92% expressed interest in buying wood furniture certified as legal and coming from responsibly managed forests.
  • When it comes to textiles for the home:
    • 95% expressed interest in purchasing textiles labelled with a third-party certificate as “safe,”
    • 97% want to see certification for “quality materials.”
    • 87% want certification that textiles are produced at a verified environmentally friendly, safe and socially responsible facility.
  • 69% would work with an environmental safety-conscious interior designer if style and cost were comparable.
  • 90% think the chemicals and materials used when manufacturing furniture are important or very important to their purchase decision process.

Supporting UK Creative Industries

  • GIC is aimed at Interior Designers and Interior Architects,
  • supporting them with the tools and data needed to offer sustainable and healthy interior design options to their clients.
  • GIC could also serve other UK creatives including:
  • Furniture Designers, Nautical Architects, and Exhibition Designers.

Size of challenge? There are:

  • 20,000 practising interior designers in the UK (British-Institute-of-Interior-Design, 2021)
  • 46,000 architects (ONS, 2023).
  • Furniture designers and makers
  • Nautical Architects and boat builders
  • Exhibition designers and makers

2 minute introduction:

Introduction / background

  • Hi, I’m BrianSpecMan of NGS Ltd.
  • creator of design & decision tools for building professionals
  • Including Green Apple awarded GBC & GRC
  • Green Building & Retrofit Calculators


  • Home renovation is showing a surge in demand for environmental and healthy home interiors.
  • It is no longer enough to only consider their carbon-footprint.
  • We need to avoid materials off-gassing into airtight energy efficient homes.
  • Designers lack the tools to compare material emissions
  • and struggle to provide evidence for their specification choices.


  • Green Interior Calculator (GIC) will be a design and decision tool
    • including many impact calculators
  • GIC scrutinises material and product data to calculate a wide range of outputs.
  • GIC will have a designer-focused user-interface.
    • Designers will be able to select from
    • furniture, fittings and furnishings,
  • comparing emissions data between them.
  • GIC users will become:
    • carbon- and chemistry-literate,
    • able to choose intuitively
    • without compromising creativity.
  • GIC has great education potential
    • with career focussed competencies:
    • Interrogating studio designs,
    • informing better material choices.
  • Graduates will want to use GIC in employment
    • as witnessed with GBC.


  • GIC will be used by interior designers, architects and other creatives.
  • GIC will be low-cost entry,
    • to encourage wider adoption.
    • available as a one-off or by subscription,
  • GIC is built around essential product impact datasets
    • But allows manufacturers to enhance their information
    • with downloadable literature.

Why NGS Ltd.

  • Building on 4 years developing GBC & GRC:
  • NGS will work with HiiGuru’s network of tech, software & design professionals
  • We will want features in GIC to enhance GBC suite of tools later.

GIC Green Interior Calculator Logo by NGS ltd. BrianSpecMan

Green Interior Furniture Analysis

GIC Green interior Calculator Furniture materials

GIC will collect data on materials and their properties

GIC Green interior Calculator Furniture Components or Sub-assemblies

GIC will create component or sub-assemblies made of those materials

GIC Green interior Calculator Furniture Assemblies

GIC will collate data from the assemblies of materials to make furniture

GIC Green interior Calculator Furniture material ingredients, impacts, life cycles

GIC will then present impact output data related to service life

GIC Green interior Calculator Furniture AssembliesGIC Green interior Calculator Furniture dimensions areas and volumes

GIC will quantify materials volumes to multiply impacts againsts

Dimension will also see used to filter materials

GIC Green interior Calculator Bespoke Furniture assembly and dimensions

GIC Bespoke furniture will calculate volumes for any permutation of assemblies and mixture of materials

Green Interiors Calculator (GIC) In depth:

  • Green Interiors Calculator (GIC) is a design and decision tool that enables interior designers to assess and compare environmental and health metrics across different products including furniture, furnishings and materials.
  • At NGS, we define sustainable design as HERACEY™:
    • healthy, environmental, resourceful, appropriate, competent, effective and yardstick.
    • GIC will facilitate the selection of materials to meet the HERACEY™ definition;
    • steering material choices away from resource intensive products with negative impacts on the environment and indoor air quality,
    • towards local, natural, biobased, low carbon and carbon negative alternatives.
  • Designers will be able to produce evidence-based interior designs and specifications that meet customer demands for sustainable, healthier homes.
  • For example, avoiding products that can emit toxic fumes into the home (from fire retardants, glues, paints, dye and detergents used in manufacture) or that have a negative impact on the global environment.

Green Interior Calculator (GIC)

  • GIC is a design and decision tool that helps interior designers to engage with homeowners’ ambitions to have more environmental, healthier homes.
  • GIC seeks house details and client preferences to personalise proposals.
  • GIC helps designers to address HERACEY™ issues (ensuring homes are healthy, environmental, resourceful, appropriate, competent, effective and yardstick).
  • GIC works at material, product, element and whole fit out levels and allows accurate numerical evaluation of many properties of material choices, and permits comparison of options.
  • GIC includes a bill of quantities so that initial and running costs can be considered simultaneously.
  • GIC addresses methods, materials and product choices of finishes, furniture and equipment, for complete fit-outs and even improving energy efficiency with internal insulation.
  • GIC permits users to choose off the shelf products but also uses models of generic furniture types to specify bespoke furniture choosing each component from a materials library that automatically feeds data to allow numerous calculations to occur instantaneously.
  • GIC allows designers to prepare proposals in advance, deliver robust evidence-based data so everybody understands the end result before commencement.
  • GIC also permits any substitutions proposed during the works to be evaluated by performance, impact, short and long term costs.

Innovative Solution to an Industry Challenge

  • The environmental impact of interiors can be significantly higher than a building due to their short life cycles and requirement for frequent replacement.
  • 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.
  • GIC 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.
  • GIC will enable designers to compare and evaluate their design and specification choices, providing evidence-based solutions that meet specific client’s preferences for environmental, healthy homes.

New Revenue Stream

  • GIC builds on NGS’s already powerful Green Building Calculator (GBC) and Green Retrofit Calculator (GRC) to build a new tool for a new market.
  • GIC delivers a significantly more powerful user-friendly design and decision tool with markedly more detailed analysis of embodied impacts of material choices. The new interface provides an opportunity to secure the tools with Intellectual Property Rights (IPR) and more security compared to our existing MS Excel-based calculators.
  • Learnings from developing GIC 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), GIC can be developed at low cost.
  • Software and UI/UX development support is provided by HiiGuru.
  • As a potential future customer, they have a strong interest in successful project delivery and are providing support at low cost alongside access to user representatives and subject experts.

Supporting Datasets

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

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 Glazing Calculator

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

GGC will support selection and specification of all internal glazing including:

  • Partitioning
  • Screens
  • Mirrors
  • Furniture

Green Screed Calculator

Green Screed Calculator GSC part of a suite of GBC Green Building Calculators by BrianSpecMan at NGS ltd.

GSC will support selection and specification of all internal floor build ups including:

  • Structural toppings
  • Levelling screeds
  • Wearing surfaces
  • Beddings

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.

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

GIC 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 *****
5th March 2024 – 9th March 2024

Green Interior Calculator GIC


Green Interior Calculator (GIC) includes many features:

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

Aimed at homeowners wanting to do improvement option appraisals; kept simple by doing as much data setting and number crunching as possible, later developed for interior design professionals

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:

HiiGuru are going to develop the GIC 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.

GIC 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 GIC 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

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:

  • GIC is only yet created less 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

Green Interior Calculator GIC C#2152 End.

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