How long does it take to design and build a custom home


If the promise of building a custom home in 12 weeks is marketing BS, how long does it really take to build your home?

The most honest and unsatisfactory answer is: it depends.

“It depends on what?” you might rightfully ask.

To which I would reply, “It depends on how long each of the steps listed below takes.”


There are three main architectural drawings, each serving a different purpose:

  • Concept Drawings (a simple floor plan);
  • Planning Drawings (site plan, floor plan(s) and elevations with basic measurements);
  • Working Drawings (detailed information on each plan of the Planning Drawings plus more details on footing, roofing, plumbing, electrical and cross-section construction information).

While the architect could start and finish all the above within a couple of days, the homeowner reviewing and adjusting these plans to best match their vision takes weeks and sometimes months to finalise.

Allow between six to eight weeks for the designs.

Engineering and Council Approvals

Civil Plans are the only engineering document required once you finalise the Planning Drawings when it comes to the Planning Approvals.

From the 19th of March, based on the new Planning and Design Code, it can take anywhere from 3 days to 30+ days to get the Planning Approvals (that’s not allowing for a few weeks of potential public notification).

When it comes to applying (through a private certifier) and obtaining (council stamped plans) the Building Approvals, the list of the required documentation looks something like this:

  • Working Drawings;
  • Engineering Footing Report;
  • Energy Rating Report;
  • Structural Calculations;
  • Framing Design;
  • CITB Levy.

Once completed, we send all the above documents to the private certifier, who, after doing their due diligence, send them to the council for approval.

Allow between three to six months for the engineering and council approvals.

Estimation and Quoting

Historically it would take us two weeks to estimate a project and a building quote.

Currently, with suppliers stretched to their maximum capacity and subcontractors spoiled with more work than they know what to do with, it takes us to double the time.

Allow at least four weeks to get a reliable and detailed quote from a professional builder.


Between two to three meetings with the builder and many visits to various suppliers, selections take time.

They are not something to rush through nor something to procrastinate on.

Allow four to six weeks for selections.

Loan Approval

When it comes to the construction loan approval, all the builder can do is provide the homeowner with the bank pack, i.e. plans, contract, specifications, and insurance.

From there, it is with the mortgage broker and the banks.

Based on what we have recently seen with our clients, allow at least four weeks for the loan approval.

Construction: Footing

Somewhat of an industry standard, the construction clock starts ticking once the slab is poured.

And yet, depending on the type of footing and the slope of the land, a lot may need to happen prior to that.

From retaining works to soil movement, before any trench is dug and steel installed, the work required before the concrete is poured may vary a lot from project to project.

Allow two to four weeks for footing plus a few more for concrete curing.

Construction: Framing

The current timber shortage makes determining how long the framing stage will take more of a guessing endeavour.

As a consequence, more builders than ever are now building with steel frames. But in doing so, the time to get the steel frame designs (see Engineering and Council Approvals above) is now 75 working days.

Yet, the unchanged time differentiator remains the number of stories your house has.

Allow between four (single-storey house) to eight (double-storey house) weeks for framing.

Construction: Cladding and Roofing

Like the framing stage, when it comes to external walls and roofing, the time to complete a double-storey house doubles compared to a single-storey one.

The materials used also play an important role.

Lightweight cladding is quicker than good old brick. A steel roof is faster than a tiled roof.

Allow between six (single-storey) to twelve (double-storey) weeks for cladding and roofing.

Construction: Lock-up and 2nd Fix

Although this may appear to be nothing more than an unpainted front door installation from the street, there is a great deal happening inside.

That a lot involves:

  • First fix plumbing, electrical and aircon;
  • Insulation and gyprock;
  • Flashing and cornices;
  • Second fix carpentry;
  • First coat of paint;
  • Tiling; and
  • Joinery.

These are all done by a different group of contractors and one group at a time. A delay in one of the groups creates unpleasant surprises for the rest of them.

Allow eight to twelve weeks for lock-up and 2nd fix.

Construction: Final Fixes

This stage should take the least amount of time when compared with the other ones.

However, similar to the previous stage, the contractors are lined up in a dependable fashion, which increases the risk of delays if they are late to complete their part.

Included in this stage are:

  • 2nd fix electrical and aircon;
  • Benchtops;
  • Plumbing fixtures installation;
  • Flooring;
  • Mirrors and shower screens;
  • Painting; even
  • Builder’s cleaning.

Allow two to four weeks for final fixes.

Construction: Weather and Variation Delays

Very common for projects starting in winter, weather delays can be expected since construction starts outdoors, and bad weather can impede outside work considerably.

However, variation delays are likely to be longer than weather delays.

Although we ensure all inclusions are selected and confirmed with our clients before construction starts, it is still typical for someone building their dream home to change their mind and modify a few things in the house.

Depending on how far in the process that happens and the type of changes that occur, sometimes a simple change can delay the project by weeks, and when it happens more than once, that can turn into months of variation delays.

Allow two to four weeks for weather and variation delays.


Some of the steps listed above can happen simultaneously (even if partially so), and at HBC Homes, we do all we can to complete each stage on time through careful scheduling and management.

And yet, a lot that goes into designing and building a custom home is affected by other factors and people outside the builders’ control.

So, to answer the how-long question using the best/worst-case scenario, from the initial design brief to the final handover and getting the keys to your home, it can take anywhere from 55 weeks to 92 weeks.