Planning an extension is one of the most exciting decisions a homeowner can make. More space, better flow, a home that actually works for how you live.
But it is also one of the most misunderstood processes in residential construction. The mistakes that cost homeowners the most time, money, and stress rarely happen during the build. They happen well before a slab is poured, often before a designer is even engaged.
Here are the five most common planning mistakes we see, and what to do instead.
Why Style Is a Design Decision, Not Just a Finishes One
A style isn’t just a colour scheme. It’s a set of proportions, materials and light requirements that need to be built into the home, not added afterwards.
Want large, low-set windows for a light-filled look? That’s an orientation and glazing decision made at design stage. Want exposed timber joinery or a curved archway? That affects framing and trade sequencing. The earlier a style direction is on the table, whether you’re planning a custom build, a renovation or an extension, the more control you have over cost and outcome.
Mid-Century Modern
Mid-Century Modern takes its cues from 1950s and 60s residential architecture: low-pitched rooflines, raked ceilings, post-and-beam framing and a strong visual link between indoor and outdoor living.
It’s one of the most requested looks we see, and for good reason, it ages well and suits a lot of blocks around Albury-Wodonga. The catch is that raked or cathedral ceilings with exposed beams need to be engineered differently to a standard truss roof, and the large sliding or stacking doors that make the indoor-outdoor connection work need structural steel lintels and adequate footings. Both are easy to price properly if they’re on the table at design stage, and expensive to retrofit if they’re not.
Modern Farmhouse or Cottage
This style combines simple gabled forms and a generous verandah with a more contemporary, low-fuss material palette than a traditional farmhouse.
The verandah is usually the detail that carries the whole look, and it’s also the detail with the most cost variables: roof pitch, post spacing and footing requirements all change depending on how deep and how exposed it is. Board-and-batten or vertical cladding profiles, which are common in this style, also cost more in labour than standard horizontal weatherboard. Worth pricing both properly in your original quote rather than adding them in as a variation later.
Coastal or Hamptons
Hamptons-style homes pair a coastal colour palette with classic weatherboard detailing: higher ceilings, VJ panelling, symmetrical facades and window shutters.
The ceiling height is the one that catches people out. Going above the standard 2.4 to 2.7 metres lifts wall framing and cladding costs across the entire home, not just the room you’re picturing with the high ceiling. VJ panelling and shutters are often treated as a later finishing decision, but scoping them into the contract from the start keeps them from becoming a variation once the build is underway.
Industrial
Industrial style borrows from old warehouses and factories: exposed brick, structural steel, polished concrete and services left visible rather than hidden behind plasterboard.
Leaving structural steel, ducting or plumbing exposed means those elements need to be finished to a higher standard than usual, since there’s nothing hiding them, and coordinated carefully at documentation stage so trades aren’t working around each other on site. Polished concrete floors need to be planned from the slab stage. It’s not a finish you can decide on once the slab is already down.
Two Styles Worth Having on Your Radar
Beyond the four above, we’re seeing more homeowners bring these directions to the table too.
Modern Heritage borrows classic proportions, arches, picture rails and panelling from older homes and pairs them with a simpler, lower-maintenance build approach. It’s a strong direction for renovations and extensions, where new work needs to sit comfortably next to an original home without replicating every period detail. Our Wilson project, a 1950s cottage-style renovation, is a good example of keeping that original character while bringing the home up to modern standards.
Warm Minimalism keeps clean, simple lines but softens them with natural stone, warmer timber tones and layered lighting instead of a single bank of downlights. That layered lighting needs to be planned into the electrical drawings before rough-in, not decided once the walls are up. Our Wirraway extension, light-filled and pared back, shows how that softer, more considered feel comes together in practice.
Bringing a Style to Your Builder Before You Design, Not After
The most useful thing a homeowner can do with any of the styles above is bring it to the table early, ideally before floor plans are locked in, not once you’re choosing tapware.
At AVK Homes, this is exactly why we run a proper feasibility and Value Management process before quoting. It gives us the chance to align the style you want with what your site, budget and layout can actually deliver, so there are no surprises once construction starts.
If you’re planning a new build, renovation or extension and want to talk through how your preferred style translates into a real design and budget, get in touch with AVK Homes to start the conversation.
