So, you’ve weighed up your options and you think a custom build project is the best path forward for your family. Great! Now comes the logistics of working out what exactly you want and whether you can afford it.
Don’t worry, it’s not uncommon to feel overwhelmed when it comes to custom home build costs. If you’ve never undertaken a architectural custom build or a knockdown rebuild project before, it can be confusing to work out what exactly you need to account for in your total building budget.
Read on to find out just what costs you need to consider when undertaking a custom build project.
Preliminary Costs
Preliminary costs are all about paying experts to gather all the relevant data and information about your block of land, compiling it into detailed architectural plans, and creating structural reports. From these documents, a custom builder can accurately price up the project and your local council can determine if the project can proceed. Let’s break it down.
Preliminary costs will include any or all of the following:
Design Fees: This is the cost to work with a Building Designer, Draftsperson, or Architect to create bespoke blueprints and working drawings for your new home. The plans will show the exact footprint of the build, the internal layout, and what materials and premium finishes will be used. Both a Building Designer and Architect have a deep understanding of building laws, zoning restrictions, and requirements to advise you on the best design for your lifestyle.
Soil Tests & Engineering: Soil tests are carried out by a structural engineer who will take core samples from your land to determine the specific soil classification. This dictates what type and size of concrete slab or foundations are required to support your custom home. The engineer will then create a structural report and engineering plans to guarantee the building is perfectly sound.
Other Consultants: Other consultant fees you may need to factor in include land surveyors and energy-efficient assessors. A comprehensive contour survey plan of your property is an absolute requirement for your council or certification submission. You will also need a BASIX certificate (or relevant energy rating tool) to prove the new custom home meets modern sustainability and thermal efficiency requirements.
Private Certification and Council Lodgement Fees: Nearly all custom build projects require a Development Application (DA) or Complying Development Certificate (CDC) lodgement. This process can be straightforward or long and drawn out depending on your local council, any relaxation requirements, or constraints on your property (such as character overlays, bushfire zones, or heritage listings).
A Private Certifier can handle the entire approval process, along with managing mandatory inspections on your new custom home throughout the entire construction timeline. Both the DA/CDC lodgement fees and Private Certification fees must be factored into your upfront budget.
All of these preliminary reports, plans, and tests will be used by your builder to accurately price up the full construction costs. If you bring a custom builder on board early in your design phase, they can help coordinate all necessary consultants and track the project as it moves through these initial stages, making the entire process much smoother for you.
While it can be difficult to pinpoint exact figures at the very beginning, an experienced builder will be able to give you reliable estimates once they have a firm understanding of what you want to achieve with your custom home.
Construction Costs
This is the one question nearly everyone wants an answer to right off the bat: How much are the actual build costs? It’s pretty much the same as asking how long is a piece of string? Any figure you receive prior to doing preliminary site investigations and having your final custom design locked in is simply a ballpark figure. It is almost impossible to compare your custom build with another project and provide an accurate ‘rough guess’, as site conditions, slope, and choices in finishes vary wildly.
The good news is, once you have all the preliminary work complete and your architectural design finalized, an exact contractual price can be provided. Building costs for a custom home typically include:
Site preparation, excavation, and retaining walls
Concrete slabs, steel reinforcement, and structural formwork
Timber or steel framing
Plasterboard and internal linings
Skirting, architraves, and detailed carpentry
Custom internal and external doors
High-performance windows and glazing
Roofing, cladding, and guttering
Bespoke cabinetry and joinery
Premium flooring and carpet
Tiling and advanced waterproofing
High-density insulation
Professional internal and external painting
Premium kitchen and laundry appliances
Architectural lighting & electrical layouts
Plumbing, drainage, and plumbing fixtures
Initial landscaping, driveways, and perimeter pathways
All up, there is a lot to factor in and a lot that can affect your costs (the price range for fixtures, smart home automation, and material finishes can vary significantly).
If you are gathering proposals for a new build, make sure you are comparing apples for apples. A quality custom builder will provide a transparent proposal that includes absolutely everything laid out in a clear and concise manner (think 15 to 20 pages long), while generic volume builders may provide simplified and vague quotes that lead to confusion over what is actually included. The latter option inevitably opens the door to costly variations and significant budget blowouts mid-build.
Incidental Costs Incurred During Construction
Some of the custom build costs that many homeowners overlook are the lifestyle and incidental expenses incurred while construction is underway on your block.
Because you are building a brand-new custom home from the ground up (or knocking down an existing home), you will need to live elsewhere for the duration of the build. Renting a temporary home, moving costs, and storage fees for your furniture all need to be explicitly written into your overall financial plan.
You should also factor in the baseline utilities needed to power the construction site, as the electricity and water usage during the primary build phases will be tied to your site accounts.
Other Home Extension Costs to Consider
Before work commences on-site, we highly recommend you speak to your insurance company about your coverage requirements. All reputable custom builders will have comprehensive Home Building Insurance and Public Liability for your protection during the build, but you will need to ensure your personal assets and transitional arrangements are fully protected.
Once your custom home is complete, you will need to set up a brand-new building and contents insurance policy. Your new home will have a significantly higher replacement value than your old property, so your coverage and premiums will need to be calculated to reflect the true value of the finished custom home.
Buying new furniture, window furnishings (like custom blinds and curtains), and decorative accessories to fill your expansive new spaces will also need some thought. We recommend putting a dedicated line item in the budget for furnishings so you aren’t left with empty rooms upon handover.
Finally, consider the ongoing climate control of your new design. If you have built a spacious, open-plan, or multi-storey custom home, your heating and cooling demands will change. Incorporating smart, passive energy-efficient measures within the structural build phase – such as premium insulation, solar panels, calculated cross-ventilation, and double glazing – will minimize these ongoing utility costs.
How to Get Started with Preparing Your Custom Build Costs
While the information outlined here is a good start to knowing what to expect, it can still be confusing to know exactly where to start when building a budget for your specific dream home.
We recommend speaking to a qualified and experienced custom home builder (that’s us!) and booking a preliminary design and build consultation. This is the absolute best way to get started. A consultation will help answer your early financial and structural questions, give you advice relating specifically to your block of land, and guide you on the safest way forward.
Booking a preliminary consultation is as easy as getting in touch and booking a time.
