When planning a full home renovation, home extension, garage conversion, granny flat or custom new home, one of the biggest questions homeowners have is:
“How do we understand what our project will cost and feel confident we are making the right decisions?”
Building your home is a significant investment and understanding how your builder approaches pricing is an important part of choosing the right team.
Before construction begins, homeowners may come across different pricing approaches, including fixed price building contracts and variable or cost-plus arrangements. Both approaches can have a place depending on the project. The important thing is understanding how they work, what they mean for you, and which approach best aligns with your expectations.
In our experience, fixed price building contracts can provide homeowners with greater clarity, structure and transparency throughout their building journey.
However, a reliable, fixed price does not begin with a contract. It begins with good conversations, careful planning and making sure everyone understands the direction of the project before construction begins.
Why Builder Quotes Can Be Difficult to Compare
Many homeowners assume comparing builders is simply about looking at the final number at the bottom of each quote. However, two builders can provide very different prices because they may not be pricing exactly the same thing.
The difference can come from:
- How well the builder understands your goals.
- The level of detail included in the proposal.
- Assumptions made about the project.
- Allowances for selections and finishes.
- How site conditions and potential challenges have been considered.
A lower price does not always mean better value. Sometimes it means important decisions have not yet been explored or certain aspects of the project have been based on assumptions.
A good building proposal should give you confidence that your builder understands what you are trying to achieve and has considered what is required to bring that vision to life.
This is why the preparation behind any building proposal matters, regardless of the pricing approach being used.
Fixed Price vs Cost-Plus Building Contracts: Understanding the Difference
The main difference between these approaches is how the project cost is determined.
Fixed Price Building Contract
A fixed price building contract means the builder provides an agreed price for a defined scope of work before construction begins.
For homeowners, this provides greater clarity around:
- What is included within the agreed scope.
- What decisions have been made.
- What the builder is responsible for delivering.
- How the project has been priced.
A fixed price approach requires detailed planning and communication upfront, so everyone understands what is being delivered before construction starts.
Cost-Plus or Variable Contract
A cost-plus contract, sometimes referred to as a variable contract, works differently.
Instead of agreeing on one construction price upfront, the homeowner pays the actual cost of the works completed, along with an agreed builder margin or fee.
This approach can provide flexibility and may suit projects where:
- The scope is still evolving.
- Decisions are likely to continue changing.
- There are significant unknown elements.
- Flexibility is a priority.
The consideration is that the final project cost may not be fully known until the work is complete.
What Should Be Included in a Fixed Price Quote?
Building plans, specifications and material selections for a Gold Coast renovation
A fixed price quote provides the most value when it clearly explains what is included and what isn’t.
Before choosing a builder, homeowners should understand:
- What work is included.
- What is excluded.
- What selections and finishes are covered.
- What allowances have been made.
- What assumptions the quote is based on.
- What items may need to be decided later.
A clear proposal helps ensure everyone understands the scope of work and reduces uncertainty before construction begins. In our experience, the quality of the preparation behind the quote is just as important as the number itself.
Important to Note
Cost plus contracts are contract models which involve added responsibility and risk for both homeowners and contractors. The Queensland Building and Construction Commission (QBCC) does not recommend using them. “The QBCC strongly recommends homeowners and contractors obtain formal legal advice before agreeing to use either of these contracts for domestic building work. Both models involve:
- Added responsibility and risk for both homeowners and contractors.
- Reduced protection for homeowners under the Queensland Home Warranty Scheme.
- Increase risk of a dispute.
Reports and complaints to the QBCC over many years suggest that the final costs under a cost-plus contract are often considerably more than the homeowners anticipated at the beginning of their building project, sometimes more than double their expectation.”
Why Dellwood Chooses to Work This Way
At Dellwood Constructions, our approach is to spend time understanding the project before putting together a fixed price. We see the quote as more than just a number – it should reflect a clear understanding of your home, your goals and the work involved.
It is the result of taking the time to understand:
- What you want to achieve.
- How your home currently works.
- What changes are required.
- What challenges may exist.
- What matters most to you.
Every project is different.
A renovation may involve working within an existing structure.
An extension needs to connect naturally with the current home.
A garage conversion may require careful consideration around structure, access and compliance.
A granny flat may need to respond to site layout, privacy and services.
A custom new home involves decisions from the ground up.
Understanding these details early helps create a more realistic pathway forward.
A Fixed Price Starts with Good Planning
One of the biggest misconceptions about fixed price building contracts is that the process begins when the contract is signed. In reality, the most important work happens before that stage. Before preparing a fixed price, we take the time to understand your project properly.
Initial Conversation and Site Meeting
The first step is understanding your vision, priorities and how you want your home to function.
During the initial site meeting, we look beyond the physical space. We discuss:
- What you want to achieve.
- How you want the home to work for your lifestyle.
- Your priorities and expectations.
- Opportunities and challenges within the property.
This allows us to identify important considerations early and discuss practical solutions.
Initial Proposal
Before progressing into detailed planning, it is important that everyone understands the intended direction of the project.
An initial proposal helps create alignment around:
- The scope being considered.
- The expected level of investment.
- What may be achievable.
- The next steps.
This stage helps ensure your goals, expectations and budget are working together before moving forward. A strong foundation leads to a more accurate and considered fixed price.
Can You Still Make Changes with a Fixed Price Contract?
Yes. A fixed price contract does not mean your project cannot evolve.
During construction, homeowners may decide they would like to make changes, add additional items or adjust selections. The important part is understanding how those decisions may affect the overall cost and timeframe.
A good builder will clearly communicate:
- What has changed.
- Why it has changed.
- The impact on cost.
- The impact on timing.
- The options available.
Our role is to make sure you understand the decisions you’re making, how they may affect your project, and the options available before moving forward.
Changes are a normal part of many building journeys. The difference is having a clear process and open communication when they occur.
Why Preparation Creates Better Building Outcomes
A successful building project is about more than the finished home. It is also about the experience along the way.
Good preparation helps create:
- Clearer decisions.
- Better communication.
- Fewer surprises.
- A smoother construction process.
A fixed price building contract provides a clear starting point because important conversations have already taken place. When homeowners understand the process and what to expect, they can move forward feeling informed and supported.
Questions to Ask a Builder Before Choosing
When comparing builders, look beyond the final number. Consider asking:
What is included in your proposal?
Understanding inclusions, exclusions and assumptions helps you compare builders more accurately.
How have you considered my home, site and project requirements?
Every project has unique considerations that need to be understood before construction begins.
When will I have certainty around my investment?
Understanding when pricing becomes fixed and what may influence changes helps set realistic expectations.
How are changes managed during construction?
A good builder should have a clear process for explaining changes and their impact.
Who will I communicate with throughout the project?
Strong communication is one of the most important parts of a positive building experience.
Final Thoughts
Choosing a builder is about more than selecting the lowest price. It is about finding a team that understands your goals, communicates clearly and provides a building process you feel comfortable with.
At Dellwood Constructions, we’ve chosen to work with fixed price building contracts because we find they provide a clearer starting point for both our clients and our team. With good planning, open communication and a well-defined scope, everyone begins the project with the same understanding.
For us, the quote is just one part of the process. Just as important is making sure you understand what’s included, how the project has been planned and what to expect as your build progresses.
The goal is to create a clear pathway forward where homeowners understand what they are building, why decisions are being made and what to expect throughout the journey.
Because a successful building project isn’t just measured by the finished home. It’s also measured by how informed, supported and confident you feel throughout the journey.
Planning Your Own Project?
Whether you’re planning a renovation, extension, garage conversion, granny flat or custom new home, every project starts with understanding your goals, your home and the best path forward.
If you’re still exploring your options, we’re always happy to have a conversation and help you understand what the process could look like for your project → Contact Dellwood Constructions.
FAQs
Q: Does Dellwood Constructions offer fixed price building contracts?
Yes. Once the project scope, requirements and inclusions have been properly understood, Dellwood provides fixed price contracts to give homeowners greater clarity before construction begins.
Q: Is a fixed price building contract right for every project?
Yes. Changes and additions can still be discussed throughout the project. However, changes may affect the overall cost and timeframe, and these impacts will be clearly explained before proceeding.
Q: Can changes be made after signing a fixed price contract?
Yes. Changes and additions can still be discussed throughout the project. However, changes may affect the overall cost and timeframe, and these impacts will be clearly explained before proceeding.
Q: Why does Dellwood have an initial site meeting before preparing a proposal?
Understanding the home, site conditions and homeowner goals helps ensure the project is approached correctly from the beginning and creates a stronger foundation for preparing a realistic fixed price.
Q: Why shouldn’t homeowners choose a builder based only on the cheapest quote?
Because quotes are not always comparing the same thing. The level of detail, preparation, inclusions and communication provided can have a significant impact on the overall building experience.
