About Watcon Constructions

The cost of renovating a home on the Sunshine Coast can vary considerably depending on the size, complexity, existing condition of the home and level of finish.

A smaller cosmetic renovation may involve updating finishes, cabinetry and fixtures, while a major renovation can include structural changes, new kitchens and bathrooms, extensions, extensive glazing, outdoor living areas and a complete transformation of the existing home.

For larger, design-led renovations, it's important to establish a realistic construction budget early. Simply applying a square-metre rate can be misleading, particularly when working with an existing structure where access, demolition, structural modifications and unforeseen conditions all influence the final cost.

At Watcon Constructions, we encourage early cost planning alongside the design process. This allows the design, scope and budget to develop together and helps avoid investing heavily in plans for a project that ultimately doesn't align with your intended budget.

While square-metre rates can be useful for early budgeting, they aren't always a reliable way to determine the final cost of a house extension.

As a general guide, it would be reasonable to allow approximately $3,500–$5,000 per square metre for a professionally built home extension on the Sunshine Coast. The actual cost can vary significantly depending on the design, site challenges, structural requirements and level of finishes selected.

Extensions also involve much more than simply constructing the additional floor area. The new structure needs to integrate with the existing home, which can involve demolition, structural alterations, roof modifications, engineering, electrical and plumbing changes, upgrading existing areas and making good where old and new construction meet.

Factors such as difficult site access, sloping blocks, soil conditions, extensive structural work, architectural detailing, glazing, kitchens, bathrooms and premium finishes can all push a project towards or beyond the upper end of this range.

For this reason, we recommend using square-metre rates only as an early feasibility guide. The best way to establish a realistic construction budget is to assess the existing home, understand the proposed design and develop preliminary costing specific to the project.

This allows the design and budget to be considered together before progressing too far into the documentation process.

It depends on the type and extent of work being undertaken.

Some minor renovation work may not require building approval, while structural alterations, extensions and other significant building work will generally require plans, engineering and approval through a building certifier. Depending on the property and proposed works, additional town planning or council requirements may also apply.

Factors such as overlays, boundary setbacks, building height, site constraints, character requirements and the location of existing services can all influence the approvals required.

You don't need to have all of this worked out before approaching a builder.

For major renovations and extensions, Watcon Constructions can work alongside your architect, building designer, engineer and building certifier to help establish the documentation and approvals required for your particular project.

Either approach can work, and the right starting point often depends on how developed your ideas already are.

For significant renovations and extensions, we believe there is considerable value in involving an experienced renovation builder early in the design process.

Architects and building designers bring enormous value in developing the design, functionality and character of a home. A builder can complement this by providing practical construction knowledge, identifying potential site challenges and providing feedback on how design decisions may affect the construction budget.

Having the builder and designer communicating early can help keep the design, construction methodology and budget moving in the same direction.

Watcon Constructions is happy to work with your existing architect, building designer or interior designer. If you haven't engaged a designer yet, we can also help connect you with professionals who suit the style, scale and requirements of your project.

Two builders can review the same renovation and arrive at very different prices.

Often, the difference comes down to what has actually been included in each quotation.

One builder may have allowed for a particular material or construction method while another has assumed something completely different. Prime Cost items, Provisional Sums, exclusions, structural requirements, site supervision, subcontractor quality, material specifications and the level of detail within the documentation can all affect the price.

This is particularly important with renovations, where there can be considerably more complexity and uncertainty than with a straightforward new build.

A lower initial quotation doesn't necessarily mean a lower final construction cost. If important items haven't been properly investigated, documented or allowed for, they may appear later as additional costs or variations.

When comparing builders, we recommend looking beyond the final figure and understanding the scope, inclusions, exclusions and allowances behind it.

At Watcon Constructions, we place a strong emphasis on detailed pre-construction planning and costing so our clients have a clear understanding of what is included before construction begins.

Choosing a builder for a major renovation is about much more than comparing prices.

You'll potentially be working closely with your builder for many months, and they'll be responsible for managing a significant financial investment while working in and around your home.

Look for a builder with relevant renovation experience, appropriate licensing and insurance, strong communication and a clear process for managing the project from pre-construction through to handover.

It's also worth looking closely at how they prepare their quotations and contracts. Ask what has been included, what has been excluded, how selections and allowances are handled and how variations will be managed during construction.

For architecturally designed or highly detailed renovations, consider how comfortable the builder is working alongside architects, building designers, interior designers and engineers.

Most importantly, choose a builder whose approach and values align with your own. Good communication, transparency and trust are incredibly important throughout a major renovation.

We encourage prospective clients to take the time to meet with their builder, ask questions and understand their process before making a decision.

Absolutely. This is part of the preliminary building process which we tailor to your project.​

At Watcon Constructions, we take pride in providing detailed and accurate quotes. There is a fee for the quote that covers the time and effort we invest in quantifying materials, assessing project requirements, and engaging our trusted trades for tender pricing. This thorough approach ensures transparency, minimises surprises during the project, and allows us to deliver better value for your investment.

We typically focus on one project at a time to ensure exceptional attention to detail and quality. While we overlap projects where possible, the planning, design, and approval process often takes 6-9 months. To avoid delays, we recommend starting discussions as early as possible to ensure your project stays on track.​

Budget blowouts are often the result of incomplete planning. At Watcon Constructions, we invest heavily in the upfront quoting and planning process. Our detailed Quantity Take-Off (QTO) helps identify challenges early, allowing us to plan for them and avoid unexpected costs down the line. While unforeseeable issues can sometimes arise during construction, our experience and thorough preparation minimize surprises, ensuring your project stays as close to budget as possible.​

It all starts with a conversation. At Watcon Constructions, we guide you step-by-step through the entire renovation process. From planning to final finishes, we help simplify decisions and provide access to our preferred suppliers, making selections straightforward and stress-free. Our expertise ensures that your vision comes to life without feeling overwhelmed.​