5 Mistakes And 5 Tips for Building Estimation in Victoria

Estimating is the backbone of every successful construction project. A small error in your quote can lead to massive cost overruns, delays, or lost profits.

Here are the top 5 estimation mistakes, along with 5 expert tips to avoid them, helping Melbourne builders.

Top 5 Estimation Mistakes

1. Guessing Instead of Referencing Real Costs

Too many builders still rely on gut feeling or old quotes instead of actual, updated data.

Mistake: Relying on outdated supplier prices or previous project quotes.

Consequence: Blowing out your margin before the build begins.

2. Inconsistent Mark-Up Application

Without a system, mark-ups can be inconsistent across products and services.

Mistake: Applying different mark-up rates across categories without transparency.

Consequence: Underquoting and reducing your profit margin.

3. Missing Items in the Take-Off

Manual take-offs or poor systems can easily miss components like fixings, waste, or underlays.

Mistake: Skipping critical line items or miscalculating quantities.

Consequence: Cost blowouts during procurement or mid-construction.

4. Not Using a Price File

A custom price file is your secret weapon for controlled, reliable quoting.

Mistake: Not using a structured price file tailored to your builds and suppliers.

Consequence: Quoting inconsistencies and confusion when ordering.

Did you know: ACS has an established price file with pre-negotiated prices with our trusted supplier network.

5. Poor Workflow Between Estimating & Design

When designers and estimators don’t speak the same language, things fall through the cracks.

Mistake: Disconnected processes between interior selections and take-off estimates.

Consequence: Reworks, miscommunications, and additional costs.

5 Estimating Tips

1. Start with Accurate, Complete Plans

You can’t estimate what you don’t understand. Incomplete or unclear plans lead to guesswork and missed costs.

 Tip: Always request the latest, finalised architectural and engineering plans before starting your estimate.

2. Break the Project Down into Work Packages

Don’t try to price the whole build in one go. Break it down into logical sections like earthworks, slab, framing, roofing, etc.

 Tip: This structure helps you track scope, compare supplier quotes, and reduce the risk of overlooking line items.

3. Include Contingency and Overheads.

It’s tempting to quote lean to win the job—but make sure you allow for the unexpected.

Tip: Add a contingency percentage (typically 5–10%) for unknowns, and don’t forget to cover your business overheads (admin, insurance, tools, etc.).

4. Leverage ACS’s ConSmart Platform

Our ConSmart platform streamlines your project estimating, design selections, and document storage in one place.

Tip: Use ConSmart to sync your design selections with your estimating team—no double handling, no missed details.

5. Keep Your Estimating & Design Teams in Sync

At ACS, our services bridge estimating and design. Keep the communication lines open to

Tip: Schedule regular handover points where designers, estimators, and builders can review selections, specs, and quantities.

Inaccurate estimating is more than a nuisance—it can derail entire projects. Whether you are a Melbourne or regional Builder, you can take advantage of ACS’ professional take-off services, a solid price file, structured mark-up strategy, and the powerful ConSmart platform to bring clarity, control, and consistency to every project quote.

Contact us today to discuss and transform your estimation process!