REX for Builders

AI-powered compliance, built for Australian builders.

REX is a purpose-built AI compliance assistant developed specifically for Australia's building and construction sector.

Designed to support licensed builders, site supervisors, and construction professionals. REX simplifies compliance by helping you interpret regulations, analyse inspection reports, and manage site documentation, all from one smart, intuitive platform.

Trusted by builders across Australia
NCC + ASTrained library
4.9★App Store rating
24/7On-demand answers
Built in AUIndustry-vetted
Product Tools & Key Features

Streamline compliance. Reduce rework.

AI tools designed to support your team, adapt to your workflows, and scale with your business.

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Ask REX Anything

A 24/7 on-demand AI assistant trained on Australian codes, regulations, and construction practices. Ask technical, site-specific questions in plain language and receive fast, referenced responses you can rely on.

Compliance Information, Delivered Clearly

Get accurate, actionable insights across construction methods, tolerances, approved materials, and defect classifications. No guesswork, no BS.

Inspection Report Analysis

Upload any inspection report and REX will review each item, cross-check against regulatory frameworks, and identify whether rectification is required. Save hours of manual analysis while reducing risk exposure.

Built by the industry, for the industry

REX was developed in consultation with builders, building consultants, certifiers, and legal experts, ensuring it understands how construction really works on the ground.

New on Rex Builder

More than answers. Get the job done.

Beyond AI compliance, Rex Builder now handles the operational, legal, and financial side of every project: store and share documents, book trades, run onsite numbers, get legal and accounting support, and lock in the certificates and reports your job actually needs. All at fixed, transparent prices.

Workflow tools, included in your selected plan
Pro & Premium

Job Folders

Store all your plans, permits and documents in one place. Request quotes from several tradies at once, straight from the job folder, so you save hours of follow-up calls and email chains.

One folder. Multiple quotes. Time saved.
Pro & Premium

Scheduling

Book trades straight from this function. Once both parties accept the booking, it lands in each calendar automatically. No double-handling, no chasing dates, far less admin.

Both accept. Both calendars sync.
Included

Quick Calc

Your onsite calculator that helps you work out site issues instantly without breaking out the spreadsheet. Designed to handle the everyday numbers that come up between jobs.

Built for onsite, not the office
Pro & Premium

Legal

Practical support with contracts, disputes, notices, and general building-related legal matters. Get guidance on contracts, payment claims, variations, defects, and delays, and prepare documents or letters when problems arise. Plus, search a complete archive of past state-based tribunal decisions and use real precedent to back your own case when it matters.

Tribunal precedent at your fingertips
Pro & Premium

Accounting

Practical financial guidance. Upload your business financials and Rex will analyse them, highlight issues, identify opportunities for improvement, and suggest where you can run a tighter operation. Plus general tax-related guidance to help you understand your position and improve efficiency, structure, or planning.

Better numbers, better decisions
Bookable services. Fixed prices, no middlemen
Bookable services are currently available for Victorian builders only. Rolling out to NSW, QLD, SA, WA, TAS, NT and the ACT. Coming soon. Want early access in your state? Get in touch.
From $ 179 VIC only

Energy Ratings

Mandatory on every new build, now booked directly through Rex Builder. Single storey from $179, double storey from $239. No middlemen, no markups, tracked alongside every job.

Single $179 · Double $239
$ 549 flat VIC only

Performance Solutions

When your surveyor flags a non-standard condition, get a performance solution certificate through Rex Builder at a flat $549. Real scenarios, fast turnaround, no hunting for a consultant.

Certificate issued, fast turnaround
$ 329 VIC only

Soil Tests

Book soil testing through Rex Builder at $329. Mandatory for every build, at a fraction of contractor rates. Fast turnaround, certified reports, and tracked alongside every job in your account.

Fast turnaround. Certified report.
From $ 299 VIC only

Land Surveys

Re-establishment surveys from $799, feature and level surveys from $299. Booked directly through Rex Builder. No runaround, no inflated rates, tracked and on record in your account.

Feature/level $299 · Re-est $799
Watch a demo

See how to use the functions inside REX.

A 60-second walkthrough. Press play to see Rex Builder in action.

app.askrex.com.au/builder Demo
Ask REX
"What's the maximum overhang on a bottom plate under AS 1684?"
Maximum overhang depends on the load & species.
  • Up to 50 mm for non-load-bearing
  • Up to 25 mm for load-bearing studs
  • Always confirm against the engineer's bracing schedule
AS 1684.2 NCC Vol 2 3.4
Inspection report · 14 items
Cornice junction crack. Cosmetic, not a defectNo action
Tap leak, main bath. Rectify under HBARectify
Render touch-up. Within toleranceNo action
Door alignment. 4 mm out, exceeds toleranceRectify
Hairline crack, bed 2. Cosmetic onlyNo action
3 rectify · 11 no action · $0 wasted on cosmetic items
Book a service
Energy rating
$179
VIC · 3 day turnaround
Soil test
$329
VIC · selected
Land survey
$299
VIC · feature/level
Performance solution
$549
VIC · flat
Total today: $329 Confirm booking →
Watch on YouTube
Who REX is for

Built for the people who keep the site moving.

From sole traders to large commercial outfits. REX is shaped around how your team actually works.

Sign up free
Licensed Builders

Get fast, code-referenced answers and end the back-and-forth on inspection reports.

Owner-builders · Volume · Custom
Site Supervisors

Settle disputes on the ground with the right NCC / AS reference in seconds.

Daily diary · Subbies · Defects
Construction Managers

Tighten margin and audit trail across every job, without another platform to learn.

Cost · Compliance · Reporting
Sole Traders & SMBs

All the answers, forms and tools usually locked behind a $300/hr consultant.

Trades · Small builders · 1 to 10 staff
More than an assistant

A whole ecosystem behind every job.

Beyond compliance answers, REX gives builders the resources, community, and admin tools to run a tighter operation.

Training & Education Hub

Access a growing library of industry-vetted compliance resources, code interpretations, and real-world examples to keep your team informed and your site compliant. All content reflects the most recent changes to building codes and standards.

The Builders Hub

An exclusive, professional community for licensed builders. Share experience, troubleshoot real-world issues, and gain insights from peers on everything from compliance and disputes to site management and client comms.

Forms & Documents Library

Instant access to templated documents, legal forms, defect notices, inspection checklists, and site paperwork. Designed to streamline day-to-day operations and reduce time spent on admin.

Plans to suit your workflow

Pricing that scales with the job.

REX offers a range of plans to suit solo builders, growing businesses, or large commercial operators. Flexible pricing, scalable tools, and priority support, backed at every stage of the job. Start your free 30 day trial today.

Starter Plan
$ 79 / month
  • Ask REX Anything
  • 10 Reports per Month (extra $5 / report)
  • 1 User Included
  • Forms & Documents
  • Training & Education
  • Builders Hub
  • Quick Calc
Subscribe Now
Premium Plan
$ 199 / month
  • Ask REX Anything
  • 50 Reports per Month (extra $5 / report)
  • Up to 5 Users · $49/m per additional
  • Forms & Documents
  • Training & Education
  • Builders Hub
  • Quick Calc
  • Jobs & Scheduling
  • Services (Soil Test, Land Survey, Performance Solution, Energy Rating)
  • Data Analytics
  • Legal & Disputes
  • Accounting
Subscribe Now
Enterprise

More than 5 users? Let's talk.

For construction companies and commercial operators with more than 5 users. Everything in Premium, plus volume per-user pricing, dedicated onboarding, and a named account manager.

  • Volume per-user pricing
  • Unlimited users
  • SSO & SCIM
  • Dedicated account manager
  • Priority support
  • Custom integrations
Get a quote Typical reply within 1 business day
Questions?

Everything you wanted to ask.

What is REX?

REX is an AI-powered compliance and inspection assistant designed to help builders and construction professionals interpret building codes, standards, and respond to inspection reports accurately and efficiently.

What's the difference between REX and other AI platforms like ChatGPT?

REX is not a general-purpose chatbot. It's a purpose-built AI compliance assistant for the Australian construction industry, trained on a curated library of building codes, Australian Standards, regulatory frameworks, and industry-vetted resources. REX doesn't pull random answers from the open internet. Every response is grounded in trusted construction sources, so you can act on what it tells you with confidence.

Who is REX for?

REX is built for licensed builders, site supervisors, tradespeople, building consultants, and construction managers who want a fast, reliable assistant to help navigate compliance and defect reporting.

How does REX help with inspection reports?

REX can read inspection reports, identify which items need rectification, and flag unnecessary or non-compliant claims, saving time and money.

What's the difference between REX and a building inspector?

REX does not perform physical inspections. It is a digital assistant that helps interpret and respond to inspection findings, check standards, and guide rectifications, acting as your technical and compliance consultant.

Can I upload my own inspection report for review?

Yes. With a paid subscription, you can upload PDF or Word-based inspection reports. REX will review the content and generate a compliance-based response.

What kind of questions can I ask REX?

You can ask REX anything from "What's the maximum overhang allowed on a bottom plate?" to "Do I need expansion foam around a driveway?" to "Does this defect require rectification under the NCC?"

Is REX available on mobile?

Yes. REX is accessible via both desktop and mobile, with a simple and intuitive interface designed for use onsite.

Can REX help me dispute a defect?

Absolutely. REX provides clear, code-referenced explanations that can help you professionally dispute unjustified defect claims based on building standards.

How accurate is REX?

REX uses AI models tailored to construction law and standards. It's designed to be highly accurate, but always encourages users to cross-check critical decisions with a licensed building surveyor or legal professional.

Is my data secured?

Yes. All data uploaded to REX is encrypted and stored securely. We do not share your documents or personal information with any third parties.

What's included in a subscription?

Depending on your plan, you get a set number of report uploads, unlimited compliance questions, access to forms and documents, training content, the builders hub, and multi-user functions.