Cost to Build a House in Sydney: Why Tenders Differ So Much

Ken Yazici
Oct 7
3 min read

When researching the cost to build a house in Sydney, it’s easy to be tempted by the lowest quote. But when it comes to construction tenders, what matters most isn’t always what’s included; instead, it’s what isn’t.

At Betacon Construction, we often meet clients who’ve received a wide range of prices for seemingly similar projects. Understanding why those differences exist can save you from costly surprises later on.

Recently Completed Duplex Build in West Ryde

Here’s what you need to know before signing your next building contract.

1. The Real “Cost to Build a House in Sydney”

Many people assume the cost to build a house is simply the total figure in the tender. In reality, tenders can vary dramatically based on what’s been included, excluded, or assumed.

Some builders present a low entry price that appears appealing, but may omit essential items such as landscaping, driveways, retaining walls, or even basic finishes. These gaps often become expensive “variations” during construction.

A transparent tender provides you with the full picture from day one — helping you compare apples to apples.

Concrete slab being poured on a Sydney construction site, showing the early stages of a home build and real cost to build a house in Sydney.

2. Provisional Sums and Prime Cost Items

Two of the most misunderstood parts of a building tender are Provisional Sums (PS) and Prime Cost (PC) Items.

These are allowances and not fixed prices. For example:

A Prime Cost item might be $2,000 for bathroom fixtures, but your chosen fittings could easily exceed that.
A Provisional Sum may estimate excavation or site costs, which can increase once work commences.

Suppose one builder’s tender includes more realistic allowances while another’s uses minimum figures. In that case, their total prices will differ — but the more transparent one will likely save you money in the long run.

3. Exclusions: The Hidden Costs of “Cheap” Quotes

One of the biggest reasons tenders vary is what’s left out. Common exclusions you should look out for include:

Site works and excavation
BASIX and energy compliance reports
Service connections (water, gas, electricity, NBN)
Driveways, fencing, and landscaping
Council or certifier fees
Upgrades to finishes or fixtures

When comparing quotes, always ask each builder to list their exclusions clearly. A lower tender might look attractive until you add back everything that was missing.

Timber frame of a new home under construction in Sydney, representing structural work and builder tender comparisons.

4. Understanding Site and Council Conditions

In Sydney, not all blocks are equal. A builder who knows your local council, whether it’s Ryde, Parramatta, or Canada Bay will understand zoning rules, setbacks, and approval timeframes.

If a builder underestimates these site-specific costs, it can create unexpected variations later.

That’s why working with a local builder who’s familiar with Sydney’s conditions can protect you from delays and cost blowouts.

5. Transparency Over Price

At Betacon Construction, we believe a tender should be more than a price list. It should be a roadmap for the entire build. That’s why our tenders are detailed, itemised, and easy to interpret, giving clients clarity before a single brick is laid.

When you receive multiple tenders, don’t just compare the totals. Look at: