One of the first questions we get asked is simple: how long does it actually take? Granny flat build time is easy to get wrong if you only count the build itself, because approval and site works run alongside it. The good news is that a factory-built home is one of the quickest ways to add a second dwelling to your backyard.
Here is a realistic, stage-by-stage timeline based on over 30 years building modular and transportable homes across NSW. Times are a guide, since your block and your approval path will shift things a little either way.
It starts with a chat. You tell us about your block, your budget and who the granny flat is for, and we talk through which designs and approval paths suit. This is also when we flag anything that might affect cost, like a sloping site or services that sit a long way from the sewer.
Allow about a week to settle the basics and choose a direction. If you want to come and see the homes in person, our display centre is at 1355 The Northern Road, Bringelly. You can also browse our range of modular homes before you visit.
Next we lock in the design, the inclusions and a fixed quote. If you are starting from one of our standard layouts, this is quick. If you want to customise, it takes a little longer to finalise the drawings.
This is the stage to make your decisions: number of bedrooms, kitchen layout, finishes and any covered outdoor areas. Remember that under the NSW Housing SEPP 2021 the internal floor area can be up to 60 square metres, while covered patios, verandahs and carports sit outside that figure.
Most granny flats are approved through a Complying Development Certificate, or CDC, assessed by a private certifier rather than the full council DA. For blocks of 450 square metres or more in a residential zone, this typically takes about 10 to 20 business days.
If your block does not meet the CDC criteria, it goes through a council Development Application, which takes longer and varies by council. Our guide to how granny flat approval works in NSW explains both paths so you know which one applies to you.
This is where the modular advantage really shows. Your home is built in our factory in about 8 weeks, inside a weatherproof, controlled environment. Rain does not stop work, materials stay dry, and quality is checked at every stage.
The clever part is that this build can happen while approval is being finalised and while your site is being prepared. Because the timelines overlap, you are not waiting for everything in a straight line. You can see the full sequence on our our process page.
While the factory build is underway, your site gets ready. That means clearing, levelling and setting the foundations, plus running services toward where the home will sit.
This is where Sydney's two big cost and time multipliers appear: rock or sandstone close to the surface, and how far services have to run to the sewer. A flat, well serviced block is quick. A sloping or rocky one takes more work. Either way, it happens in parallel rather than adding weeks to the end.
Once the home is finished and the site is ready, we transport and install it on site in about 2 days. This is the part homeowners love. Your backyard is only a work site for a couple of days, not months.
For families already living on the property, that short install window is the whole point of going modular. There is far less disruption than a traditional on-site build.
After install, there are final connections and finishing touches: tying in services, any external works like a path or driveway, and a final clean and check. Then it is handover and you are done.
External works such as driveway and landscaping can run roughly $8,000 to $23,000 as a guide, depending on how much you do. Some homeowners tackle landscaping themselves afterward to spread the cost.
For a straightforward block on the CDC pathway, many projects run from first enquiry to handover in roughly three to four months, with the factory build and site works overlapping in the middle. A DA, a tricky site or heavy customisation will extend that.
The honest answer is that an exact timeline depends on your block and your approval path, which is why we give you a fixed quote and a realistic schedule up front.
Usually the factory build at about 8 weeks, though it overlaps with approval and site works. Approval can also be the bottleneck if your block needs a council DA rather than CDC.
Much of the work overlaps. Site preparation and the factory build run alongside the final approval stages, which is a big reason modular is faster than traditional construction.
The best way to know your real timeline is to have us look at your block. We will tell you the likely approval path, the build schedule and a fixed price. Explore our modular granny flats and studios, then contact us to get started.
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