How architects manage budgets: keeping your new home or renovation on track

Budget is the question homeowners ask us about most, and for good reason. Building a new home or doing a major renovation is one of the biggest investments you'll ever make, and nobody wants an unpleasant surprise halfway through.

Where budgets go wrong

We've taken over projects where the original design came in more than 20% over what the homeowners could spend. In our experience, early estimates can vary from 10 to 20% as a design develops, which is within industry norms. That's exactly why we price at a few stages. Beyond that range, the options are hard. You either find more money, or you go back and redesign, which costs time and fees.

Usually, the cause isn't one big mistake. Overruns often build up gradually through upgrades and choosing higher-end finishes. A better tile, a larger window or nicer cabinetry each seem reasonable on their own. Together, they add up quickly. Good budget management means pricing those decisions early, while there's still room to make trade-offs.

Our first step: an opinion of cost

Before we decide how to bring a builder on board, we give you our own opinion of cost: our estimate of what your home is likely to cost to build.

We're not cost consultants or quantity surveyors, and we don't claim to be. However, once we have early design drawings, our experience with similar homes in Brisbane and on the Sunshine Coast means we can advise on likely build costs. It isn't a quote, but it gives you a realistic starting point early on, and you hear it from us directly rather than from a junior team member.

If your wish list and your budget don't line up, we'll tell you before you've spent money developing a design you can't afford to build. Whichever pathway you choose, every later estimate is checked against this benchmark.

If you haven't bought your block yet, our feasibility study gives you this kind of early read before you commit. Site conditions affect cost too, which our sloping block guide covers in more detail.

Getting builders to quote, or bringing one in early?

There are two main ways to bring a builder on board.

Competitive tender means a few builders are invited to quote on the finished drawings. This can give you a sharp price. The downside is that you're choosing mostly on numbers, and you may end up with a builder you don't connect with well.

Early contractor involvement (ECI) means a builder joins the conversation while the design is still taking shape. You might not always get the lowest possible price. However, you get real pricing advice early, practical input on how your home will be built, and a builder who feels invested in the outcome. In our experience, that sense of shared ownership is very valuable.

How we manage your budget with a builder on board early

This is the approach we've seen work well:

1. With our opinion of cost as the benchmark, we prepare early design drawings with just enough detail for a builder to price. If council rules apply to your site, the design already responds to them.

2. The builder gives a first estimate of the cost.

3. We compare that estimate with your budget and adjust the design if needed, while changes are still easy and inexpensive.

4. We develop the drawings further so the structural engineer, surveyor and any other specialists your home needs can do their work.

5. The builder prices your home again. With more detail, this second estimate is much more accurate.

6. Once the budget lines up, we apply for building approval, the permit needed before construction can start.

The second round of pricing is usually where amounts for interior finishes are set, such as tiles, cabinetry, lighting and fixtures. That's when we recommend starting interior design, because there's then a clear figure to work towards rather than designing first and pricing later.

If you'd rather get builders to quote

The process is much the same. After our opinion of cost, an independent cost specialist (a quantity surveyor) prices the early design drawings instead of a builder. They price it again once the engineer and other specialists have done their work. We then invite builders to quote, help you choose one, and apply for building approval.

Keep in mind that a quantity surveyor's estimate is based on market trends and averages. It's a reliable guide, but the real test is the builders' quotes.

The takeaway

Budgets rarely blow out in one moment. They drift when costs aren't checked at the right stages. Pricing early, starting with our own opinion of cost, then pricing again and making design decisions with real numbers in front of you is what keeps your home on track. We're with you at every one of those stages, and we treat your budget carefully from day one.

If you're planning a beautiful new home or a major renovation in Brisbane or on the Sunshine Coast and want to talk through what your budget could realistically achieve, get in touch. We're always happy to have a chat.

Frequently asked questions

How accurate is an architect's opinion of cost?

An opinion of cost is our professional estimate, not a quote. It's based on your early design drawings and our experience with similar homes, and gives you a realistic benchmark from the start. It's then refined through builder or quantity surveyor pricing as the design develops.

What is early contractor involvement?

Early contractor involvement (ECI) means a builder joins while your home is still being designed. They give early pricing and practical building advice before the design is finalised, which helps keep your home in line with your budget.

When should interior design start?

We recommend starting interior design after the second round of pricing. That's usually when amounts for finishes like tiles, cabinetry and lighting are set, so there's a clear figure to work towards.

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About the author

Manny Pedro is a director and registered architect at Quorum Studios, which he runs with his wife and co-director Vanessa Pedro. They design new homes and major renovations, including Queenslander homes, across Brisbane and the Sunshine Coast.

Disclaimer: This article is general information only and doesn't constitute professional, financial or cost advice for your specific project. Building costs vary with site conditions, design, specification, market conditions and builder availability. Any opinion of cost or estimate is a guide only and not a quote. Please speak with us or a suitably qualified professional before making decisions about your project.

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