5 Hidden Costs Developers Miss in Feasibility Studies
A feasibility study is one of the most important early steps in any development. It helps determine whether a project is financially viable but too often, crucial costs are underestimated or overlooked entirely.
Missing these hidden expenses can turn a promising project into a budget blowout.
In this guide, our engineers and planners unpack five common cost areas that even experienced developers can miss, along with practical tips to identify and account for them before it’s too late.
1. Site Constraints and Ground Conditions
Beneath the surface lies one of the biggest unknowns.
Soil type, groundwater, rock, or unstable fill can dramatically impact your earthworks, retaining, and foundation design costs.
What to look for:
Require a geotechnical investigation early.
Review flood, slope, and erosion overlays.
Allow contingency for unsuitable or reactive soil.
Why it matters:
Rectification costs mid-project can exceed initial estimates by tens of thousands if ground conditions aren’t properly assessed.
2. Infrastructure and Service Upgrades
Your site may not have the existing capacity for water, sewer, stormwater, or power to support your intended development.
Developers often budget for new connections, but not for the upgrades, extensions, or easements that councils or authorities may require.
What to look for:
Review existing service locations and capacities.
Check council infrastructure charges and developer contribution plans.
Factor in traffic or stormwater mitigation works.
Why it matters:
Hidden infrastructure costs can quickly erode profitability especially on infill or subdivision sites.
3. Regulatory and Approval Delays
Time is money. Every month lost in the approval process adds holding costs, loan interest, and potential price shifts in materials or labour.
What to look for:
Understand the full approval pathway before lodging.
Engage professional advice early to reduce “information requests.”
Identify whether additional studies (traffic, flood, bushfire, etc.) are required.
Why it matters:
Even small documentation errors or non-compliance can delay approvals by weeks or months.
4. Design Changes During Construction
Even well-planned projects encounter changes on site, but reactive design changes can be costly.
Minor layout tweaks can trigger new engineering designs, re-certification, or non-compliance with the approved plans.
What to look for:
Ensure design documentation is finalised before tender or construction.
Involve your engineer early to review constructability.
Allow contingency for possible variations or compliance amendments.
Why it matters:
Every design change impacts time, cost, and coordination and can lead to rework or contract disputes.
5. Post-Construction Requirements
The finish line isn’t always the finish.
Many developments incur post-completion obligations that weren’t accounted for in the original feasibility, such as:
As-constructed drawings
Maintenance bonds
Certification and final inspections
Landscaping establishment or monitoring periods
Why it matters:
If you don’t factor these costs upfront, you risk eroding your project margin right at handover.
Feasibility studies should do more than estimate build costs, they should anticipate risks.
By identifying these hidden costs early, you can create a more accurate financial model and prevent costly surprises mid-project.
JC Engineers works with developers, builders, and councils to provide accurate pre-design assessments, feasibility reviews, and engineering advice that keep projects on track and compliant from day one.
