The Homeowner’s Guide to Modern GBQ

Most people who set out to build a home get their first real cost figure late, from one builder, on that builder’s terms. Modern GBQ turns that around. You describe the project; the Grace Estimation Method (GEM) computes the engineered quantities — concrete, reinforcement, walls, finishes — with its working shown; the platform prices every line from real published supplier offers plus trade labour rates; and only then do builders see the scope, all of them pricing the same structured bill of quantities, compared blind before you learn who is who.

Quote pathways

Ballpark · Design · Detailed

GEM formulas in the Foundation Pack

64, across five families

Every priced line shows

which offer or rate priced it, and why

Builder comparison

blind first — numbers before names

Where: Create account, from the home page

Registration asks for three things: your email and password, where you’ll use Modern GBQ (Australia or Egypt — this decides which Terms of Service and Privacy Policy apply to you, and each opens in a new tab so you can read it first), and your agreement to those two documents. Every legal document is also always available at the Legal page, without logging in — the Australian set in English and the Egyptian set in Arabic.

If your account has two-factor authentication enabled, logging in asks for the current six-digit code from your authenticator app after your password. Two-factor is optional today and is switched on through the account API rather than a screen; an in-app enrolment page is on the way (see What’s coming).

Where: Organisations, in the sidebar

Everything in Modern GBQ belongs to an organisation — even a single homeowner. Create one with the type Homeowner / Developer, give it a short code and a name, and you automatically become its first member. Your projects, quotes and builder shortlists all live under it. Each person has one Homeowner / Developer organisation — if you already belong to one, the Organisations page points you to it instead of creating another, so every project you run stays in one place. (The other organisation types — Builder, Supplier and Consultant — are for the people you’ll work with; a builder or supplier organisation also has to accept the Marketplace Agreement, which a homeowner organisation does not, and goes live only after the Modern GBQ team has verified it.)

From the organisation’s page you can see its members and add another registered person by their email address — useful if you’re building with a partner and both of you want access to the same project. They must already have a Modern GBQ account. Any active member can suspend another member and reactivate them later, without losing history.

Where: Projects → Create a project

A project is the container for one build. It carries a code, a name, its country and currency, and a status that advances by itself as you work: Draft → Estimating → Quote ready → Quote approved → Builder sourcing. Its workspace has a panel for each part of the picture:

• Site — the address of the build and its pin on a map. Type the address into Find address and pick the match (where the server has address lookup switched on), or fill the form by hand; then click the map to place or move the pin on the lot. The locality is also what selects the trade labour rates used in pricing, and it is the only part of the address a builder sees during blind comparison — the pin and the street address stay with you.
• Buildings — each building, its storeys (with level numbers) and the rooms on each storey (by room type and quantity). This is the structure the estimate is organised around.
• Quotes — every quote you’ve started, with its pathway and status, and a “Builder-ready” badge once one qualifies (more on that below).
• Drawings & documents — the project’s architectural drawings, site plan, specifications, reports and photos, each marked as shared with invited builders or kept private (see Drawings and documents).
• Builders — your builder-sourcing workspace, once a quote is ready for it.
• Participants — who else is on this project and in what role.

Where: the Participants panel on your project

Add anyone from one of your organisations to the project by their email, with the role they actually play: Owner, Developer, Architect, Engineer, Project manager, Estimator, Builder, Supplier and more. Participants can see the project workspace; you can deactivate a participant at any time (and reactivate them later) without losing any history.

Where: the Drawings & documents panel on your project

Upload the files that describe the build and keep them with the project: architectural drawings, the site plan, specifications, reports, photos and anything else. Each upload takes a kind, an optional title and description, and a file of up to 25 MB — PDF, PNG, JPG, WebP, DWG, DXF, Word, Excel, CSV or plain text. Anyone on the project can download a document; a person who manages the project can upload, share and delete them.

Every document is either shared with invited builders or private to the project team. Drawings, site plans and specifications are shared by default, because they are what a builder prices from; reports, photos and other files are private by default. You can change either way at any time with one click. Shared files appear on each invited builder’s invitation page, beside the priced scope, for the length of the engagement — nothing is shared before you send the project to the builder panel, and nothing private ever leaves the project team.

Where: the Quotes panel → Start a Ballpark or Detailed quote

A quote follows one of three pathways, from fastest to firmest. Pricing works the same way on every pathway and never waits on a supplier: each line takes the best source available — a published supplier offer first, then a recent market price (a supplier’s confirmed price ahead of one the platform’s market scan found), then an indicative item rate, then a category-average rate — and tells you which one it used. What changes between pathways is how much of the input is yours:

The Quote Wizard runs in four numbered steps, and you can rerun any of them:

1. Material selections — the finishing materials the estimate will price. Choose a finishing quality — Economical, Standard, Good or Advanced — and apply that level’s defaults in one click, then adjust: any selection can be swapped to a listed alternative product (you record a short reason, so the change is traceable) or restored to its default. Where the catalogue holds a photo of a product, it appears beside the product’s name and beside each alternative, so a tile or a tapware range is chosen by what it looks like. Each selection shows where it came from: Quality default, Your choice, Estimator override or AI recommendation.
2. GEM quantities — run the Grace Estimation Method over the project. It produces the engineered quantities (concrete volumes, reinforcement weights, wall areas and so on), listed by rule code with the quantity each one computed. The full working — every formula, the inputs it used and its confidence label (Derived, Preliminary, Benchmark or User input) — is kept with the run and is open to anyone with access to the GEM Formulas screen in the Configuration Centre.
3. Price the quote — turn those quantities into money. Each line takes the best price source available for its material — a published supplier offer, a recent market price where no offer exists, or an indicative or category rate where there is neither — adds a waste allowance, prices the trade labour to install it, and the quote sums to subtotal, tax and total. Pricing never waits on a supplier. You can set the site’s condition — Easy (labour × 0.90), Standard (× 1.00) or Difficult (× 1.20) — which scales the labour hours, never the material.
4. Review — the full breakdown: materials vs labour, tax, total, and every line with how it was priced and any warnings. From here you mark the version ready, submit it, and approve it.

Every priced line carries a resolution that tells you exactly what its figure rests on:

Labour is resolved the same way: each line shows Trade rate (with the trade, hours and rate that produced it) or Not priced. Labour never blocks a quote — an unpriced trade simply contributes zero and says so.

Nothing is overwritten. Each time you re-price, a new numbered version is created; the versions table keeps them all, and the Review step can put any earlier version side by side with the current one so you can see exactly what a material swap or a design change did to the total. A version can also be re-priced from a chosen earlier version as its starting point.

A quote moves through statuses — Draft → Ready → Submitted → Approved, with a brief Calculating while a new version is being priced. Approving locks that version as the agreed basis: no further versions can be added to an approved quote. If you started with a Ballpark and want to go further, upgrade the pathway: the quote returns to Draft on the higher pathway, and every earlier version stays in the history.

The Builder readiness checklist on the quote page tells you plainly what stands between this quote and builder sourcing, and links you straight there once every check passes. The rules are: an approved Detailed quote is builder-ready; an approved Design quote is builder-ready once architectural drawings exist; a Ballpark quote is for budgeting only and never goes to builders.

Where: the Builders panel on your project

The builder marketplace is designed around one idea: compare offers before identities, so the numbers speak first.

1. Start an engagement from your builder-ready quote. The response deadline is set automatically from the platform’s response window (five days by default) — the engagement screen shows the window that applies.
2. Invite builders from the platform’s builder directory, right on the engagement screen — search by name or code, or leave the box empty to list everyone. Each entry carries the builder’s name and code, star rating out of 5 and stated capacity, and the directory lists only organisations the Modern GBQ team has verified, so every builder you can invite has been checked. You and anyone who manages the project with you (an owner, developer, administrator, architect, project manager or estimator on the participants list) can invite; no staff step sits in between.
3. Builders respond to the exact scope your quote defines — every included line with its quantity and price, plus the lines you excluded, listed separately. A response is one of Accept, Revised proposal, Request discussion or Decline, and a builder can revise it for as long as the engagement is open for responses; you always see their latest.
4. Read the comparison report. While it’s blind, responses are labelled Builder A, B, C… in a fixed order — you see every number and term, not the names.
5. Record your feedback — one confirmation that you have read the blind report, at or after the deadline. That’s the step that closes the response window and reveals identities: your first impressions are formed before any name can influence them, and the moment of reveal is on record.
6. Select your preferred builder and notify them. They acknowledge or decline.

The engagement’s own status tracks all of this: Open for responses → Responses received → Preferred builder selected → Selection notified → Acknowledged. Acknowledgement is the platform’s last step, because what follows — the contract — happens between you and the builder directly.

If things change

• You can withdraw a selection (a written reason is required); the builder is not penalised by your withdrawal.
• If a builder declines after being selected, that costs them half a star on their public rating — and you can immediately select another builder from the same responses, without re-running anything.
• If no response suits, you can revise the quote and run a second round — after a cooldown following the previous comparison report (five days by default), and a quote can go to builders only a limited number of times (twice by default). Both limits are platform settings and the engagement screen shows the ones in force. A genuinely new quote starts the allowance again.

Where: Notifications and Support, in the sidebar

The Notifications centre collects what happened while you were away — builder selections, support updates — with an unread badge in the sidebar, one-click mark-as-read (per item or all at once), and per-channel preferences you control. Today the In-app channel is live; Email and SMS can be switched on in your preferences but are not yet connected to a delivery provider, so nothing is sent through them yet.

Support is a real ticket system: describe the problem, give it a priority, track its status (Open → In progress → Resolved → Closed), and get notified when it’s resolved.

• Have your plans before you estimate. Ten minutes verifying areas and room counts against the drawings is worth more than any amount of tweaking later — every quantity flows from the inputs.
• Start Ballpark, finish Detailed. Use the fast pathway to make design decisions cheaply, then upgrade — the version history preserves the whole journey.
• Swap materials in the wizard, not on paper. Changing a selection and re-pricing shows the exact cost consequence in minutes, with the reason recorded.
• Read the price sources. A quote full of Category average lines is a budget; a quote full of Supplier offer lines is a scope priced from real, current market offers. A Market price line sits between the two: a price seen in the market recently — dated, with a link to the listing it came from, and marked as either supplier-confirmed or found by the platform’s market scan. The price-source column tells you which you have — the total is valid either way, but the mix tells you how firm it is.
• Compare versions before approving. The side-by-side view is the clearest picture of what changed and what it cost.
• Trust the blind report. Judge the responses before the names — that’s the fairest read you’ll ever get of the market for your project.
• Use the reasons fields honestly. Written reasons on swaps, withdrawals and declines are what make the record trustworthy when you look back at it.

These are planned and not yet available. Nothing in the rest of this guide depends on them.

• Direct project inputs for GEM — entering floor areas, storey heights, room dimensions and the other measured inputs the formulas use straight from the Quote Wizard, instead of relying on the platform’s configured defaults.
• Reading your drawings — extracting areas and room counts from an uploaded plan straight into the GEM inputs, and checking the site against local planning rules.
• Two-factor enrolment screen — switching on authenticator-app protection from your account page.
• Email and SMS delivery of notifications, once the providers are connected.

• Every figure Modern GBQ produces is an estimate prepared with the Grace Estimation Method — not a quotation or an offer from any builder or supplier.
• Modern GBQ does not process payments, hold funds, or create contracts. Engagements are agreed directly between you and the builder, outside the platform.
• During blind comparison, builders see your project’s locality, not your identity or street address; you see their offers, not their names — until you record feedback.
• Sponsored or promoted placement, wherever it appears, is labelled and kept apart from the objective figures.
• The full Terms of Service, Privacy Policy and related documents are always at the Legal page, in your market’s language.