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Free guidance from a builder of nearly 20 years

Helping Australian Homeowners Build and Renovate With Confidence.

Build Companion exists to put you in control of your renovation or new build — before you spend a dollar. Free articles, a free budgeting tool, and honest, experience-based guidance from someone who's worked construction sites since he was 16.

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No account required to read. Free tools, free guides — the paid system is there if and when you want it.
Sean Mahoney (right) with his father Greg (left) in SGM Building uniforms
Who's behind this

Written and built by a licensed Australian builder — not a marketing team.

I'm Sean Mahoney. I started on construction sites at 16, and over nearly 20 years I've worked on everything from bathroom renovations to homes worth $30 million-plus — including five years running SGM Building with my father, Greg. Build Companion is what I wished every homeowner had access to: the same project-management discipline the best clients get, made available to everyone.

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Free education

Straight answers, before you need to know them.

Practical guides on the decisions that actually determine how your project goes — written from nearly two decades on Australian building sites, not recycled from overseas blogs.

Budgeting Builder Selection Contracts Renovations New Homes Hidden Costs Planning Quantity Surveyors Project Management
Contracts

Cost-Plus vs Fixed-Price Building Contracts, Explained

What each contract type actually means for your budget and your risk — plus a founder's-eye view on when each one makes sense.

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 Builder Selection

How to Choose a Builder

Licensing, insurance, references, and the questions that reveal more than any glossy portfolio.

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 Hidden Costs

Common Building and Renovation Mistakes to Avoid

The ordinary, well-known failure points that quietly derail most budgets and timelines — and how to avoid them.

Read the guide →

Browse all free articles

The problem

Your builder has a project manager. You don't.

A renovation or new build is one of the biggest financial decisions most people ever make — and homeowners run it with a notes app, a group chat, and hope. Meanwhile the builder's side of the table has systems, templates, and process built over hundreds of projects.

"How do I know if my builder is doing a good job?"

Without a reference point for what's normal at each stage, you can't tell a good build from one that's quietly cutting corners.

"What happens if I make the wrong decision?"

No one hands you a framework for the dozens of decisions — selections, variations, contract terms — that shape the outcome.

"How do I stop this blowing our budget?"

Most budget blowouts aren't bad luck — they're costs nobody had a system to see coming.

Free education is step one

Articles and the calculator help you plan. The system helps you run the whole project.

Everything above is free, and always will be. When you're ready to actually manage the build week to week — budgets, builder communication, defects, handover — that's what the complete system is for.

See what's inside the system
Build Companion Financial Dashboard page
When you're ready

The next logical step: the complete Build Companion system.

Free articles and the calculator help you plan and ask better questions. Renovation System and New Home Build System are the full project management platform — every stage from design through handover, for a one-off $99.

For homeowners renovating or extending

Renovation System

Built for the chaos, the hidden problems behind existing walls, and living through it — not a general guide with a few renovation notes bolted on.

Explore the Renovation System
For homeowners building a new home

New Home Build System

Nobody hands you a manual for building a house on a vacant block. This is the manual — what's supposed to happen at every stage, before it's covered up.

Explore the New Home Build System

Not sure which is you? A large extension can feel like both — see how the systems work to help decide, or start with whichever describes more of your project.

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Why homeowners trust Build Companion

Built specifically for people spending $150,000–$1.5 million with no construction background.

Not owner-builders. Not tradespeople. Busy professionals who have the money to build but not the industry experience to manage it confidently — and who have the most to lose from getting it wrong.

Australian owned and built, not adapted from an overseas template — the process, terminology, and contract stages match how building actually works here.

We're a new company and won't pretend otherwise with invented reviews. What you can check for yourself: 12 sections / 62 templates / 75 pages (Renovation) and 10 sections / 57 templates / 68 pages (New Build) — real product, screenshots above.

Everything educational is free and always will be. The paid system is a one-off $99, nothing else — no subscription, no account required, and a 14-day refund if it's not right for you.

Frequently asked

A few quick answers.

Is the calculator and the articles really free?+
Yes — permanently. The calculator, every article, and the weekly emails cost nothing and always will. Renovation System and New Home Build System are separate, optional, one-off purchases for people who want the complete weekly-use project management system.
Do I need both paid systems?+
No — almost everyone needs exactly one. Renovation System is for an existing home you're renovating or extending; New Home Build System is for a new home from a vacant block or knock-down-rebuild.
Is there a subscription?+
No. Both systems are a one-off $99 purchase — pay once, keep it for the life of your project and beyond.

Read the full FAQ

Start with what's free — the calculator and the guides.

No account required. No cost, ever.

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