In construction, confidence is essential, but untested assumptions are risky and often lead to major financial complications.

A familiar pattern emerges in many troubled projects: owners, driven by vision and ambition, bypass or ignore expert cost advice, assuming intuition and determination will suffice. They treat cost planning as a formality instead of a decision-making tool. The result: projects that stall, spiral, or collapse under the weight of poor pre-construction planning.

The key to successful construction is good pre-construction planning.

In construction, confidence can be a powerful tool—but misapplied, it becomes costly. A recurring theme in project failures is the owner’s belief that they know better. CEOs who are very proficient in managing their business are very confident leaders. However, just like doctors, you can’t be an expert in everything, particularly in a specialized world of construction cost planning.

Here are the most common mistakes in cost planning:

1. Abuse of cost per square meter assumptions

Cost per square assumptions is very useful, if you are estimating from 30,000 feet with little details. These assumptions and references are useful for conceptual planning.

However, these references should be taken with caution, as every project is unique in itself. There are multiple factors that can affect the project cost.

A cost per sqm figure is an average—it flattens all nuances of the design, materials, systems, and site conditions into a single value.

A hospital with the same number of beds might sound similar but when you go into the details, they differ in soil conditions, sustainability features, parking requirements, number of clinics, height limitation, etc.

Two projects with the same size but different functions or construction methods are not comparable by square meter cost. The other was made with reinforced concrete on bored piles, and the other was made with structural steel on Isolated footings.

Oversimplification of complexity can be misleading.

Cost per sqm doesn’t break down into components. This makes it impossible to understand where costs are concentrated (Pareto Rule), evaluate value engineering options, and where to make smart substitutions.

A project in an urban CBD will differ from a rural project due to material and equipment logistics and labor rates.
A highway might have the same length and width, but it differs in slope and soil conditions.

Cost per sqm ignores contextual uniqueness, leading to false confidence. It should be cross referenced with the details so as not to oversimplify the complicated.
Second costly mistake:

2. Bidding out without your own internal Bill of Quantities

The old school of thought was to invite at least 3 bidders to submit their bids on a set of plans without doing your own estimates first. This is chaos in the making.
Each bidder will interpret their plans as they see them and will submit a bid in their terms. If the project owner just looks at the bottom-line figure and decides on the winning bid, most of the time, this will lead to litigation and contractual conflicts.

Setting the expectations right with the correct contractual and technical wordings is crucial in procuring bids.

It’s like buying a home amplifier system because it was cheapest on the shelves, only to find out that the speakers were not part of the purchase.

Completeness, compliance, and conditions. Always check this.

If you have an internal basis of reference from cost planning, the cost evaluation of bids will be easier.

3. Proceeding with the Project without a clear design criterion

Always plan with the end in mind, then work backwards so that goals are clearer to all the project stakeholders: planners, consultants, and vendors.
An example, a customer wanted to build his second hotel because the first one brought in a very profitable business.

So, the owner hired a design-build contractor, and they agreed on a price. They ended up in an expensive lawsuit because they were unclear of their own set of expectations.

In construction, design criteria are the specific requirements and standards that guide the design and construction of a project, ensuring it meets defined objectives and performance expectations. They act as a blueprint for success, outlining what the project needs to achieve in terms of functionality, aesthetics, and safety.

Without a deliberate and well-defined design criterion, the project team will be confused about which way to go.

Design criteria can be developed from historical data of past successful projects. This is where your quantity surveyor and cost planner come in.

It is very important to note that this is where experience brings in value. A cost planning team with expertise in data centers would be able to bring in a lot of value for future data center projects.

Cost engineers who are proficient in power plants might not be the most proficient in doing airports or trains. Historical data when used by a proficient cost planner is a very potent tool in ensuring your projects are optimized in terms of cost, time and over-all value.