Adelaide's Award Winning Custom Home and Renovation Specialists


What Is a Preliminary Building Agreement?

Are you planning on renovating or extending your home? Then it goes without saying you obviously want a design you love for a price you can afford. Sounds simple enough right? But how exactly do you get that without a nightmare building experience?

This is a question that stumps many homeowners, and for one reason: they don’t know what a Preliminary Building Agreement (PBA) is and why it’s so important to have one.

People often overlook this part of the building process, but by cutting corners and not doing their due diligence to understand the importance of these agreements, they end up paying more for their project in the long run.

Without a Preliminary Building Agreement you could end up with a project that isn’t designed correctly, a builder who doesn’t understand your needs to quote it properly and inclusions and specifications that are not clearly outlined; resulting in the wrong things being installed.

So, What Is a PBA?

A Preliminary Building Agreement is an agreement before construction begins, between the client and the builder. It allows the builder to collect all of the information needed, such as building plans, engineering, specifications and selections, and gain a deep understanding of the project to provide a guaranteed fixed price quote. 

This is especially important for renovations and extensions, as extensive scoping needs to be done on the existing house to ensure that the building work can be seamlessly incorporated into the home. All of this work is carried out on site.

It’s Your Insurance Policy

With a Preliminary Building Agreement, you get to build a relationship pre construction with your builder and gain trust; an essential part of any successful building project.

With all of the specifications of your project included pre construction, there’ll be no provisional sums, cost items or builder variations for unknown scopes of work. 

Because if you work with a builder who doesn’t use a PBA and goes straight to offering a building contract, then who knows what kind of costs they’ve incorporated! Working with a professional builder ensures there will be no nasty surprises!

Young couple working on their home project together and checking the house plan, real estate and home ownership concept

Collaboration Is the Key!

According to the Association of Professional Builders,  80% of home building designs don’t get built. Why? Because an architect’s job is to give you a great design, not one that you can afford..

People think they’ll save money by managing the design process themselves and then farming their plans out for tender. This isn’t true when you’re having to go back and pay for multiple designs to be drawn up because a professional wasn’t there to ensure the design is best suited to your project and your budget.

Working with a professional builder during the design process means that there is someone helping you manage and cost control the design so that you can actually afford to do it! And factoring in a Preliminary Building Agreement ensures that no time or money is wasted. Because unlike the architect’s goal, the builder’s goal is to actually build your project so they need to make sure that the design you end up with is one you can afford.

What To Expect From a Preliminary Building Agreement

These are some of the mandatory things that you can expect as part of a Preliminary Building Agreement with a professional builder:

Concept Designs 

A basic floor plan and layout of the proposed building work.

Construction Documents 

Full building plans with all details and dimensions ready for construction.


Slab design, structural steel design and timber frame design.

Soil Tests

A test of your soil to determine the type so that your slab is designed to suit your site.

3D Images and Renders 

Realistic images of how your finished space is actually going to look, with colour and depth. 

Council Approval 

Submission of all the documents to council so that they can provide approval.


A private certifier who overlooks all of the documentation to ensure that it complies with Australian standards.

Energy Efficiency Report 

A consultant who looks at your roof colour, orientation, insulation properties and glazing to make sure it complies with current energy standards. 

It doesn’t matter if you are building your first home or renovating for the seventh time…
Designing your dream home can be very overwhelming and not all information out there is clear,  that’s why we’ve put together a free and simple guide. The 6 Essential Things You Must Do For A Successful Home Renovation. Download our free guide here to discover more.

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