The first step.

If you’re looking at a home build or renovation, chances are you’ll start the process by finding the right professional to develop plans.

Gold Coast based building designer and mother-of-three Bianca Gemmill has spent close to two decades helping families take this first step - turning those big home dreams into a lovely reality.

Through her namesake studio, BCG Building Design, she's built a solid portfolio of award-winning coastal homes - developing her studio’s reputation for ‘functional, buildable spaces’, designed to match a client’s lifestyle and needs.

We caught up with her to learn more about the ins and outs of building design - including her pro tips and the ‘do’s and don’ts’ for building your best home (life)!

A building designer can bring clarity and vision to a process that can otherwise feel overwhelming.

B, let’s start from the top. Why should a homeowner engage a building designer?

A building designer can bring clarity and vision to a process that can otherwise feel overwhelming. From understanding your brief and budget to interpreting planning codes, we guide you through every stage — from the first concept through to approvals and beyond.

Bringing a building designer in early ensures your ideas are shaped with expert input from the beginning — which saves time, avoids costly mistakes, and helps you move confidently through the design and approvals process.

We don’t just draw plans — we listen, problem-solve, and design homes that are site-responsive, buildable, and uniquely yours.

It can be confusing trying to work out who is the right professional for the job. So what are some of the key differences between an architect and building designer?

While both are qualified to design homes and submit for building approvals, there are a few differences.

The main one lies in the qualification pathway — architects are university-trained and registered with a governing board, while building designers typically hold a diploma or advanced diploma in building design and are licensed or accredited by their respective state authority.

In practice, the distinction is often about approach. Many building designers (ourselves included) focus primarily on residential design and bring a highly personalised, practical, and cost-conscious perspective to their work.

At BCG, we take pride in offering boutique, considered design services without the overheads that can sometimes come with larger architectural practices.

Who should a homeowner engage first – a builder, building designer or interior designer?

Whether you’re starting from scratch, renovating, or planning a new build, your building designer should be the first point of contact. We help shape the design vision, define the scope of works, and produce plans that both the builder and interior designer can build upon.

A good building designer will collaborate with both — and at BCG, we do this regularly. We also introduce our clients to a trusted network of expert builders we work with time and time again, ensuring a seamless and reliable process from start to finish.

We love helping clients with renovations, but they’re a different beast to new builds! How do you tailor your approach for a renovation?

Renovations are often more complex than new builds, as they involve working with the unknowns of an existing structure. A building designer can assess what’s feasible, navigate constraints like rooflines or structural walls, and help reimagine your home to maximise both value and liveability.

Whether it’s a minor update or a full extension, our goal is to make the most of what you already have while creating something fresh and functional. We regularly take on renovation projects — one of my passions is transforming homes that others might see as tear-downs into beautifully modernised spaces that honour their original architectural character.

In your opinion, what are some of the key 'do's' and 'don'ts' when it comes to designing a beautiful and functional home?

Do:

Design for your lifestyle, not just trends – Consider how you live day to day, and tailor the home to suit your routines and needs.
Invest in the layout – Flow, natural light, and sightlines are the foundation of great design.
Respond to the site – Orientation, views, and topography should always guide your design decisions.
Be realistic about your budget – Engaging a builder or estimator early helps manage expectations and avoid costly redesigns later.

Don't:

Don’t overcomplicate things – Simple, well-considered spaces are often the most timeless and functional.
Don’t overlook storage – Integrated and well-placed storage is essential to how a home feels and functions.
Don’t get stuck on the ‘wish list’ – Prioritise your must-haves; it’s the fastest way to stay on budget and focus on what truly matters.
Don’t skip approvals – Understanding your local planning requirements early can save time, money, and stress down the track. We often see homeowners convert garages into living spaces without realising what's required to do so correctly and legally. Engaging a professional early ensures your plans meet all regulations from the start.

Love this! Finally, let’s talk about the budget. What amount should a homeowner budget for building design?

I recommend homeowners take the time to research when selecting a building designer. Reach out to a few and compare more than just pricing — consider their design approach, level of service, and overall experience. Fees can vary depending on the scope of work, how involved the designer is throughout the process, and the expertise they bring to the table.

Some designers quote based on an estimated square metre rate, while others use a percentage of the total build cost — which can range anywhere from 1% to 6% depending on the project and level of service.

At BCG, our process is clear and client-focused. We begin by asking you to log your enquiry through our website, followed by a desktop review of your property and project. From there, we arrange an on-site consultation where we explore your vision, site constraints, and lifestyle needs in more detail. This allows us to fully understand your project and provide a tailored, project-specific fee proposal.

We also offer optional add-on services such as consultant coordination and full design management — all scaled to suit the complexity of your build. We’re transparent with our fees and always committed to delivering genuine value for money.

Bianca Gemmill of BCG Building Design