The cost of building a custom home: What you need to know

The benefits of designing and building a custom home go beyond customising a floor plan. It allows you to tailor a home specific to your family, taste and lifestyle for decades to come. But equally, understanding the true cost of a custom home can be confusing and a major cause of angst if you aren’t well prepared and educated. Good information is hard to find, so in this blog we’re going to help you plan your budget, avoid surprises, and give you the best chance possible in making sure your dream home becomes a reality.

At Hall & Hart, we specialise in custom home builds across Sydney’s North Shore and Northern Beaches, and beyond, specialising in knockdown rebuilds and new homes on your own land. With years of experience guiding families through the entire custom home build process, we make sure you have clear insight into every cost, from site preparation to finishes, so you can make informed decisions along the way. 

By understanding the main factors that influence the cost of a custom home, you’ll be in a stronger position to make smart choices, prioritise spending, and create a home that’s truly yours, from the first consultation to moving in.

What Influences the Cost of a Custom Home?

There are a few key factors that influence how much a custom home costs:

• Site conditions – Sloping blocks, poor soil, or difficult access can increase costs due to extra site works and earthmoving.
• Design and complexity – The more intricate your floor plan, the higher the cost. Open spaces, multiple levels, or large windows all add to construction costs.
• Costs of materials and finishes – Choosing high-quality finishes and high-end fittings naturally adds to your budget, but it also adds value and longevity to your home.
• Services and infrastructure – Stormwater management, plumbing, electrical, and other utilities need to be factored in.
• Demolition (if you’re doing a knockdown rebuild) – This is an extra cost to consider. Hall & Hart can recommend reliable demolition specialists to make this part simple.
• Outside the home – Often a forgotten component with budgeting, but pools and landscaping are often high on families wish lists and should be factored in early.

Every block and every home is different. That’s why talking to a Hall & Hart Consultant early is so important, we can help you understand exactly what your site and design will cost.

Understanding Your Budget

So how much do you budget? Well a good rule of thumb is to budget for the non-negotiable upfront. We’re talking demolition, pool, and landscaping should be set aside straight away. Secondly, sound out a few builders to understand what site costs you’re looking at. Things like slope, rock, tree removal, bushfire controls, and stormwater. These rough costs need to be also set aside – better to know early so you know how much you have left over for the design and interiors. From this position, you can start to work out a bit of a square meter rate to design the house size too.

For some custom homes, you will be urged to budget for 10-20% in unplanned costs. This may be the case if your builder doesn’t have a fixed priced contract, but some builders – like Hall & Hart, have a fixed price contract, meaning once construction starts you have peace-of-mind.

Equally, it’s important to budget for preliminary costs. Hall & Hart use a pay-as-you-go model, which means you only commit financially at the right stages:

• Initial engagement for feasibility analysis and site study
• On the delivery of our design stages and pricing
• After your fixed building contract is signed

This approach helps you avoid nasty surprises, so your costs stay predictable. Because we’ve an in-house team of designers, town planners, estimators and builders, we know the common pitfalls and plan for them before construction starts.

Cost Breakdown of a Custom Home

Here’s a simple way to think about where the money goes when building a custom home:

Design and Documentation: When designing with an Architect, costs are usually between $80,000 and $120,000 depending on how complex your plans are. This covers everything from initial designs, planning approvals, compliance checks, drafting, and detailed construction drawings.

Construction Costs: On a standard block, you can expect costs to start around $3,500 per square metre for a comfortable base level spec. This includes the building labour, materials, and site management.

Site Preparation: Things like earthworks, retaining walls, or tricky slopes can add to the cost. How much depends on the soil, slope, and access to your block.

Size of the home: Seems obvious, but its easy to keep adding during the design stage. Large homes are a cost multiplier, so always be conscious of how many rooms you really need.

Fixtures and Finishes: Quality finishes and materials will bring durability and often timelessness outside and inside the home, but it is a multiplier of cost with the size of the home. When in doubt, choose materials over home size. Although $3,500 per square meter is a good budgeting starting point, interiors can move the dial to anywhere from $3,500 - $7,000 per square meter (and beyond for the high-end homes you see in Pinterest and magazines)

Pools and landscaping: Often overlooked and undercooked, but many new home dreams start with the vision of a backyard and pool for the kids. The good news is that both pools and landscaping are adaptable and can be worked with most budgets. For pools, they can cost anywhere from $50,000 - $200,000, and equally the same with landscaping.  

Breaking costs down like this helps you see where to prioritise spending and where you can be flexible.

How Much Does a Custom Home Cost in Sydney?

Costs vary depending on size, design, access and location. On a standard block, custom homes usually start from around $3,500 per square metre. For example, a 300sqm home could cost roughly $1,050,000 just for construction, before factoring in site prep, demolition, or extras like landscaping and pools.

Hall & Hart makes budgeting easier. Our in-house team can give you detailed cost estimates at each critical design milestone, so you can tweak your design, layout, or materials while staying within budget.

Tips for Keeping Your Custom Home Costs on Track

Get advice early: Speak with a Hall & Hart Consultant before buying land. Knowing your block’s limitations upfront can save a lot of time and money.

Be realistic with your budget: Include all costs, from site prep, pools and landscaping to fixtures and finishes.

Prioritise quality over size: Cheaper options may save money initially but could cost more over time. Design for enoughness and bring materials and finishes into your home that make it pop.

Work with a single team: Using our design-and-build approach reduces miscommunication and avoids unexpected costs.

By planning carefully and working with an experienced team like Hall & Hart, you can get a custom home that fits your lifestyle and your budget.

Why Work with Hall & Hart for Your Custom Home

Many homeowners start by asking: how much does it cost to build a custom home? At Hall & Hart, we take the guesswork out of that question. Our in-house design and construction team works collaboratively, ensuring that your home design aligns with your budget from the start.

Unlike traditional builds where an architect designs a house and a separate builder constructs it, our holistic design process allows you to adjust the design without excessive costs. Using advanced pricing systems, we can price your custom design at all design milestones, from hand sketches through to final documentation. Price certainty doesn’t stop there, with our fixed price building contract locking in your price for the whole construction journey.

We also manage all approvals, planning, and construction in-house. This reduces the risk of delays, miscommunication, or budget blowouts, which can be common with custom builds.

Ready to build your dream home?

Schedule a consultation with the Hall & Hart team today and let us guide you through every step of your custom home journey, from concept to completion.

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