Most people underestimate how long building takes. I’ve been in this industry long enough — as a builder, then as a building designer — to see the surprise on clients’ faces when I tell them the real timeline. From first designer meeting to keys in hand: expect 12–24 months for a custom home. Here’s why, and what you can do about it.
| Stage | Duration | Cumulative |
|---|---|---|
| Designer consultation | 1-2 weeks | 1-2 weeks |
| Concept design | 3-4 weeks | 5-6 weeks |
| Design development | 2-3 weeks | 7-9 weeks |
| Construction documentation | 3-5 weeks | 10-14 weeks |
| Building approval | 3-6 weeks | 13-20 weeks |
| Builder selection | 2-4 weeks | 15-24 weeks |
| Construction (single storey) | 6-10 months | 9-16 months |
| Construction (two storey) | 8-14 months | 11-20 months |
| Practical completion | 2-4 weeks | 12-21 months |
Realistic totals: Simple single-storey: 12–16 months. Standard two-storey: 14–20 months. Complex custom: 18–24+ months.
For a detailed look at what happens during the design stages, see our guide on working with a building designer. For approval timelines, see our guide to the Gold Coast council approval process.
The design phase is where most clients underestimate the time investment. There are three distinct stages, and each one takes longer than people expect.
Concept design (3–4 weeks): This is where we work through the brief, floor plan options, and overall form. At Design Science, every project is built in 3D from day one, so clients can actually see what they’re getting rather than trying to interpret flat drawings. This stage often takes longer than budgeted because clients — understandably — change their minds when they see things rendered in three dimensions.
Design development (2–3 weeks): Once concept is approved, we refine the design — window and door locations, ceiling heights, material selections, and external appearance. This is where the kitchen layout gets finalised, the bathroom gets dimensioned, and the outdoor living integration gets sorted.
Construction documentation (3–5 weeks): This is the stage that separates a building designer who’s also a licensed builder from someone who just draws pretty pictures. Construction documentation is the set of drawings and specifications that builders price from and tradespeople build from. At Design Science, I produce documentation detailed enough for builders to give accurate fixed-price quotes — not the vague “allow for” pricing that leads to blowouts. That takes time, but it’s worth every day of it.
Gold Coast City Council (GCCC) processes two main types of approvals, and the timelines are genuinely different.
Building Approval (BA) — Low-risk residential: Typically 3–6 weeks through a private building certifier. Most standard single-storey homes and straightforward renovations go this route. If your certifier is responsive and the documentation is clean, you can get an approval in 3 weeks. If the documentation has gaps or the certifier is busy (and they often are on the Gold Coast), it stretches to 6 weeks.
Development Approval (DA) — Code assessable: Required when your project doesn’t comply with standard residential codes — unusual lot sizes, non-compliant setbacks, certain overlays (flood, bushfire, character residential). DA through GCCC currently runs 8–12 weeks for straightforward applications, and can push to 16+ weeks if council issues an Information Request (RFI).
What triggers a council RFI: Missing information, non-standard materials, neighbour notification requirements, or an officer who isn’t satisfied with the justification for a variation. Every RFI adds 2–4 weeks to your timeline. Well-prepared documentation significantly reduces the chance of getting one — which is another reason construction documentation quality matters so much.
See our detailed guide on the Gold Coast council approval process for a full breakdown of what each path involves.
Design phase delays: The biggest cause is indecision — partners disagreeing, budget concerns requiring redesign mid-process, scope creep (adding a home office, changing the pool location, upgrading the kitchen), and slow feedback on design reviews. I’ve had design phases drag to 6 months because clients kept changing their minds. It’s frustrating for everyone, including me. The solution is a clear, committed brief upfront and a decision-making process with your partner before you engage a designer.
Wet season impact (November to March): This is a real factor that gets underestimated. The Gold Coast wet season brings afternoon storms, sustained rain events, and cyclone activity in bad years. Construction sites can’t pour slabs in rain, concrete needs curing conditions that aren’t compatible with humidity extremes, and scaffolding becomes a hazard in high winds. Budget 2–4 weeks of lost time if your construction period falls across November to March. It doesn’t stop work entirely — builders manage through it — but it slows things down. If you’re targeting a summer completion, plan accordingly.
Material supply chain: Post-COVID the building industry has normalised delays that didn’t exist five years ago. Structural steel, engineered timber products, and some electrical components can still have 8–16 week lead times. The fix is to identify long-lead items during the design phase and order early — sometimes before DA approval is granted. Your builder and designer should flag this proactively.
Trade availability: The Gold Coast has a chronic shortage of experienced tradies, particularly plumbers and electricians. A good builder locks in their subbies early, but even then, a plumber who’s flat out on a commercial job can push your timeline by weeks. This is one reason I always recommend clients start talking to builders during the approval phase, not after it.
Client changes during construction: This is the single most expensive and time-consuming cause of delays. A variation during construction doesn’t just cost money — it costs programme. If you change the kitchen layout after the plumbing rough-in is done, you’re not just paying for replumbing, you’re paying for the week of lost programme while the plumber is sourced and rescheduled. Every change requires a variation costing time and money. This is why investing in thorough building design upfront is so important — get the decisions made on paper, not on site.
Council inspection delays: Frame inspections, slab inspections, and final inspections all require council or certifier attendance. On a busy Friday afternoon with rain forecast, that inspection can get pushed. Not a major delay individually, but they accumulate.
There are things within your control and things that aren’t. Focus on what you can control.
Before design starts: Have a clear, written brief. Know your budget. Know what’s non-negotiable and what’s flexible. If you’re buying a block, know your flood overlay status, heritage status, and applicable planning scheme codes before you engage a designer — surprises here cause major delays.
During design: Respond to design reviews within days, not weeks. When your designer sends you drawings for review, a quick turnaround keeps the project moving. Delays compound — one week of slow feedback pushes everything by more than a week because the designer has other projects filling the gap.
Before lodging for approval: Talk to builders. Get preliminary pricing during the documentation phase. If a builder flags that your structural steel specification has a 14-week lead time, that’s information you need before lodgement, not after approval is granted.
During approval: Order long-lead items if your budget allows. Some clients order kitchen cabinetry, appliances, and windows during the approval phase to have them ready when construction starts.
During construction: Make no changes. I know that sounds brutal, but the discipline pays off. If something genuinely needs to change, process it formally through your builder’s variation system — don’t have casual on-site conversations about changing things.
Construction time varies significantly based on project complexity, and the differences are bigger than most people expect.
| Home Type | Construction Duration |
|---|---|
| Small single storey (150-180sqm) | 6-8 months |
| Standard single storey (180-250sqm) | 7-10 months |
| Two storey (200-300sqm) | 9-14 months |
| Large custom (300sqm+) | 12-18 months |
| Major renovation | 4-10 months |
Two-storey homes take longer not just because of the extra area — they involve additional structural complexity, more trades coordinating across levels, and more inspections. The staircase alone is a sequencing challenge that can hold up multiple trades simultaneously.
Knockdown rebuilds add a demolition phase (typically 2–3 weeks, sometimes more if asbestos is present) plus the time to re-establish services. Budget an extra 4–6 weeks compared to building on a vacant block.
For cost information by home type, see our guide on custom home building costs.
| Type | Design + Approval | Construction | Total |
|---|---|---|---|
| Kitchen and bathroom | 4-8 weeks | 6-10 weeks | 3-5 months |
| Rear extension | 8-12 weeks | 10-16 weeks | 5-7 months |
| Major renovation + extension | 10-16 weeks | 16-32 weeks | 7-12 months |
Renovations have a unique complication: the existing structure. You can design a rear extension beautifully, but when the builder opens up the existing wall, there’s often a surprise — unexpected structural members, asbestos-containing materials in pre-1990 homes, plumbing in the wrong place. Allow contingency time in your renovation timeline — 10–20% is realistic. For renovation costs, see our complete renovation pricing guide.
No — it’s illegal in Queensland. You cannot commence building work without a Building Approval in place. However, you can and should start talking to builders during the approval phase. Get preliminary quotes, lock in a builder, discuss the programme. See our guide on building approval vs development approval.
Minimal impact. Gold Coast winters are mild — you’ll get construction teams working comfortably through June and July. Summer storms cause the most delays. If you can schedule your structural and slab work for the dry season (May–October), your programme will be tighter.
Client changes during construction. Every change requires a variation costing time and money. This is why investing in thorough building design upfront is so important.
Design and approval: 3–4 months for a straightforward project with fast decisions and a responsive certifier. Construction: 6–8 months for a small single storey. Minimum total: about 10–12 months, and that’s genuinely optimistic. Don’t plan your life around the best case — plan for the midpoint.
Single storey, always. Less structural complexity, fewer trade coordination issues, simpler inspections. For equivalent floor area, a single storey can complete 2–4 months faster than a two-storey equivalent. The trade-off is site coverage versus height.
Custom home: 12–20 months from consultation to keys. Renovation: 3–12 months depending on scope. The biggest factor within your control is decision-making speed during the design phase, and the discipline to avoid changes once construction begins. The biggest factor outside your control is weather — the Gold Coast wet season is real, and it will affect your programme if construction falls across November to March.
The best thing you can do is invest in thorough design decisions before construction begins. Every dollar and week spent getting the documentation right saves three dollars and two weeks on site.
Design Science manages the complete design-to-approval process for custom homes and renovations. Book a $280 consultation to start your timeline.
David Steadman
Licensed Builder & Building Designer
David Steadman is the founder of Design Science, a Gold Coast building design practice backed by over 30 years of hands-on construction experience. One of few Australians holding both a QBCC Builder's Licence and Building Designer licence, David brings a rare combination of design thinking and practical building knowledge to every project.
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