Before you spend a dollar on design or professional fees, run the numbers. Our free development feasibility calculator tells you whether a project stacks up financially — built specifically for the New Zealand construction and property development market.
What Is This Calculator?
The NZES Development Feasibility Calculator is a free, professional-grade tool for assessing whether a property development project makes financial sense before you commit. It’s built by qualified QS professionals with decades of New Zealand construction experience, and it covers the four things you need to know before any development proceeds.
It picks up where an estimating exercise leaves off. Once you know what a project costs to build, the next question is: does it make money? That’s what this calculator answers.
We provide a walkthrough video and a link to download the Excel or Google Sheets version below.
What the Calculator Covers
Tab 1 – 36-Point Feasibility Checklist
Before a single dollar is spent, work through 36 go/no-go questions across six categories: site and planning, construction viability, financial viability, commercial and market conditions, legal and ownership, and risk. Each question gets a Pass or Fail, and you get an overall score with a verdict – Strong Go, Go with Caution, or No-Go. This turns your unknowns into a concrete to-do list.
Tab 2 – QS Elemental Cost Plan
Build a full construction cost estimate from the ground up using a professional QS elemental structure – substructure, superstructure, external envelope, fit-out, M&E services, external works, prelims, fees, and contingency. Benchmark NZD rates are included for each element. Totals feed live into the financial appraisal.
Tab 3 – Financial Appraisal
Enter your land cost, finance costs, and sales values. The calculator computes your Gross Development Value (GDV), total development cost, development profit, profit on GDV percentage, return on cost, residual land value, and loan-to-cost ratio – all automatically. Three industry benchmarks tell you at a glance whether the project is viable: profit on GDV of at least 20%, return on cost of at least 15%, LTC of 75% or below.
Tab 4 – Sensitivity Analysis (Colour-Coded)
This is the tab that changes how you think about risk. It runs a full matrix of scenarios – construction costs up or down by up to 20%, GDV up or down by up to 20% — and colour-codes every outcome. Green means viable. Amber means marginal. Red means unviable. You can see at a glance how much buffer you have before a project stops making sense — and whether you can afford for things to go wrong.
Download and Watch
Access the Google Sheets version.
Key Terms Explained
GDV (Gross Development Value)
The total value of the completed development — what all the units, commercial space, or finished product would sell for. Everything in property development starts here.
Profit on GDV
Development profit expressed as a percentage of GDV. The industry standard minimum for a viable residential development is 20%. Below that, the risk usually isn’t worth it.
Return on Cost
Development profit expressed as a percentage of total development cost. A target of 15% or above is typically required by funders and developers. Tells you what you’re making relative to what you’re spending.
Residual Land Value
What you can afford to pay for the land and still hit your required return. If the residual land value is lower than the asking price — the land is too expensive for the development to work.
Loan-to-Cost (LTC)
The proportion of your total development cost that is funded by debt. Most construction lenders want to see LTC at or below 75%. Above that, you’re likely to struggle to get finance.
Who Is This For?
- Property developers assessing sites before paying for design or professional fees
- Builders and contractors considering moving into development or evaluating development clients
- Quantity surveyors and project managers doing early-stage feasibility work
- Investors evaluating whether a development opportunity stacks up
- Anyone new to property development who wants to understand how the numbers work
- Construction company owners wanting to understand the developer’s perspective
Why We Built It
Too many developments proceed without proper financial analysis at the front end. Developers buy land at the wrong price, underestimate construction costs, or fail to account for finance, fees, and contingency — and then wonder why the numbers don’t work at the end. We built this calculator to bring professional QS discipline to the feasibility stage, where it matters most.
The calculator won’t replace a QS on a large project. But it will help you ask the right questions, structure your numbers properly, and make a much more informed decision about whether to proceed — before the money goes in.
It builds directly on the NZES Estimating Workbook. If you haven’t used that yet, start there — it covers the construction cost estimation side in detail. This calculator takes those numbers and tells you whether the development is worth doing.
If you want to go deeper on construction commercial management and post-contract administration, the NZES Full Estimating and Surveying Certificate covers everything you need — with a dedicated QS tutor and real project examples.
