The Construction Method: A Practical Guide for Contractors and Project Teams

The construction method is the specific technique used to execute a
defined scope of work. It is the most fundamental decision in construction planning –
more fundamental than the programme, more fundamental than the estimate, and more
fundamental than the resource plan. Everything else flows from it.

Choose the right construction method and the programme will be achievable, the estimate
will be reliable and the delivery team will know exactly what they are doing. Choose the
wrong method – or fail to choose at all – and the programme will be wrong, the estimate
will be wrong, and the project will be managed reactively from the first day on site.

This post explains what the construction method is, how it is chosen, what it must define,
and how it connects to the programme, the estimate and the Efficient Construction Cost (ECC).

---

What the Construction Method Is

The construction method is the answer to the question: “How will we physically build
this work package?”

It is not a vague description of the general approach. It is a specific, detailed definition
of the technique that will be used, including:

• The physical process by which the work will be executed
• The plant and equipment required to execute that process
• The sequence of operations within the work package
• The crew required to operate the plant and execute the process
• The production rate achievable with that crew and plant
• The constraints that will affect the method

A construction method that does not define all of these elements is incomplete. An
incomplete method produces an unreliable programme and an unreliable estimate.

---

Why the Construction Method Is the Most Important Decision

The construction method determines:

The Duration

The duration of a work package is determined by the production rate of the chosen method.
Change the method and the production rate changes. Change the production rate and the
duration changes. A method that produces 500 m³ per day will take twice as long as a
method that produces 1,000 m³ per day for the same quantity of work.

The Cost

The cost of a work package is determined by the plant and crew required to execute the
chosen method, multiplied by the duration. Change the method and the plant and crew
requirements change. Change the plant and crew requirements and the cost changes.

The Risk Profile

Different methods carry different risks. A method that requires working in confined
spaces carries different risks from one that works in the open. A method that depends
on a single piece of plant carries different risks from one that uses multiple parallel
machines. The risk profile of the project is largely determined by the construction
methods chosen.

The Programme Logic

The sequence of activities in the programme is determined by the construction method.
A method that requires sequential operations produces a different programme logic from
one that allows parallel operations. The critical path is determined by the method.

The Quality Outcome

The construction method determines whether the quality requirements of the specification
can be achieved. A method that is not capable of producing the required finish, tolerance
or strength will produce rework – which adds cost and time that were not in the plan.

---

How the Construction Method Is Chosen

Choosing the construction method is a structured decision-making process. It is not a
matter of habit, preference or copying what was done on the last project. It requires
a systematic evaluation of the available options against the specific conditions of
the project.

Step 1 – Understand the Scope and Constraints

Before any method can be evaluated, the scope and constraints must be understood:

• What is being built? What are the dimensions, quantities and quality requirements?
• What are the ground conditions? What does the geotechnical report say?
• What is the access? How wide are the haul roads? What is the crane coverage?
• What are the programme requirements? How fast does the work need to go?
• What are the safety requirements? Are there confined spaces, live services,
  adjacent structures?
• What are the environmental requirements? Are there noise, vibration or dust limits?
• What are the interfaces? What must be done before this work can start? What does
  this work enable?

Step 2 – Identify the Available Methods

For each work package, identify the methods that are technically feasible given the
scope and constraints. There is almost always more than one feasible method. The
evaluation should consider all of them, not just the most familiar one.

Common method choices in construction include:

Work Type	Method Options
Excavation	Open cut, rock breaking, drill and blast, roadheader, TBM
Concrete structures	Conventional formwork, jump form, slipform, precast, tilt-up
Foundations	Shallow footings, CFA piles, bored piles, driven piles, ground improvement
Structural frame	In-situ RC, precast concrete, structural steel, composite
Earthworks	Cut and fill, import/export, ground improvement, dynamic compaction
Tunnelling	TBM (EPB, slurry, hard rock), drill and blast, roadheader, cut and cover, SEM
Pavement	Asphalt, concrete (slipform or hand-laid), granular, stabilised
Pipework	Open cut, trenchless (HDD, pipe jacking, microtunnelling), slip lining
Retaining structures	MSE wall, sheet pile, secant pile, diaphragm wall, gravity wall, soil nail
Building construction	Stick-built, modular, prefabricated, hybrid

Step 3 – Evaluate the Options

Evaluate each feasible method against the key criteria:

• Technical feasibility: Can this method achieve the required quality
  in the specific conditions of the project?
• Programme: What production rate does this method achieve? What
  duration does that imply? Does it fit within the programme requirements?
• Cost: What plant, crew and materials does this method require?
  What is the total cost for the required duration?
• Risk: What are the risks associated with this method? What is the
  probability and consequence of each risk?
• Safety: What are the safety requirements for this method? Are they
  achievable in the specific conditions of the project?
• Environmental: What are the environmental impacts of this method?
  Are they within the permitted limits?
• Availability: Is the plant, equipment and workforce required for
  this method available in the required timeframe?

Step 4 – Select the Method

Select the method that best satisfies the evaluation criteria. Document the decision –
which method was chosen, why it was chosen, and what alternatives were considered and
rejected. This documentation is the evidence that the method was chosen for good reasons,
not by default.

Step 5 – Define the Method in Detail

Once the method is chosen, define it in detail. The detailed definition includes:

• The specific plant and equipment fleet
• The crew composition (FMU)
• The production rate
• The sequence of operations
• The constraints and how they will be managed
• The quality control requirements
• The safety requirements

---

The Construction Method Statement

The construction method statement is the written record of the construction method for
a work package. It is the document that communicates the method to the delivery team,
the client, the subcontractors and – if necessary – the court or arbitrator.

A good method statement is:

• Specific. It describes exactly how the work will be done, not
  vaguely how it might be done. “Excavate using a 30-tonne excavator with a 2 m³
  bucket, loading into 25-tonne articulated dump trucks” is specific. “Excavate
  using appropriate plant” is not.
• Complete. It covers all aspects of the method – plant, crew,
  sequence, constraints, quality and safety. A method statement that covers the
  physical process but not the safety requirements is incomplete.
• Readable. It can be understood by a site engineer who was not
  involved in writing it. Technical jargon should be explained. Diagrams and sketches
  should be used where they aid understanding.
• Consistent with the programme and estimate. The method statement,
  the programme and the estimate must tell the same story. If the method statement
  describes a different methodology from the one assumed in the estimate, one of them
  is wrong.

---

The Construction Method and the Production Rate

The production rate is the output of the construction method per unit time. It is the
link between the method and the programme. Without a production rate, the method cannot
be translated into a duration.

The production rate depends on:

The Output of the Key Plant

Every construction method has a key piece of plant that determines the maximum output
of the system. For earthworks, it is typically the excavator. For concrete, it is
typically the pump. For paving, it is typically the paver. The output of the key plant
sets the upper limit on the production rate.

The Balance of the Plant Mix

The production rate is limited by the slowest element in the plant mix. If the excavator
can load 10 trucks per hour but only 6 trucks are available, the production rate is
limited by the trucks. The plant mix must be balanced so that no single element is the
bottleneck.

The Utilisation Rate

Plant does not operate at 100% utilisation. Time is lost to shift changes, refuelling,
maintenance, waiting, weather and other interruptions. The utilisation rate – the
percentage of the shift that is productive – must be applied to the theoretical output
to get the realistic production rate.

Typical utilisation rates for common plant:

Plant Type	Typical Utilisation Rate	Notes
Excavator	75–85%	Depends on truck availability and material
Dump truck	70–80%	Depends on haul distance and queuing
Concrete pump	60–75%	Depends on agitator supply and pour complexity
Asphalt paver	70–80%	Depends on truck supply and mix temperature
TBM	40–60%	Depends on ground conditions and maintenance
Tower crane	60–75%	Depends on lift frequency and rigging time

The Site Conditions

The production rate must reflect the specific conditions of the site. A production rate
calculated for flat, dry ground with good access will not apply to a steep, wet site
with restricted access. The site conditions must be assessed and the production rate
adjusted accordingly.

---

The Construction Method and the Critical Path

The critical path of the project is determined by the construction methods chosen for
the major work packages and the constraints that affect them. Understanding the
relationship between the construction method and the critical path is essential for
managing the project.

A method that produces a high production rate will have a short duration and may not
be on the critical path. A method that produces a low production rate will have a long
duration and may drive the critical path. Changing the method – adding plant, increasing
the crew, working longer shifts – can shorten the duration and take the work package
off the critical path.

This is the basis of acceleration analysis. When a project is behind programme, the
first question is: which work packages are on the critical path? The second question
is: can the construction method for those work packages be changed to increase the
production rate and shorten the duration?

---

The Construction Method and the Efficient Construction Cost (ECC)

The Efficient Construction Cost (ECC) is the cost of executing a scope
of work using the most efficient methodology, plant mix and crew size that is realistic
for the specific project conditions. The construction method is the foundation of the ECC.

The ECC for a work package is calculated as:

ECC = (FMU Cost per Shift + Plant Cost per Shift) × Duration + Materials + Subcontract

Where the duration is calculated from the production rate of the chosen method. The ECC
is not the cheapest possible cost – it is the cost of doing the work properly, using the
right method, with the right plant and crew, at a realistic production rate.

The ECC changes when the method changes. A more efficient method produces a higher
production rate, a shorter duration and a lower ECC. A less efficient method produces
a lower production rate, a longer duration and a higher ECC. Choosing the most efficient
method that is realistic for the specific project conditions is the key to minimising
the ECC.

---

Common Failures in Construction Method Selection

1. The Method Is Never Defined

The most common failure. The programme and estimate are built without a defined method.
Durations are assumed. Rates are copied from previous projects. The programme and
estimate are inconsistent with each other and with reality.

2. The Default Method Is Used Without Evaluation

The method used on the last project is used on this project without evaluating whether
it is the most appropriate. The specific conditions of the new project – different ground,
different access, different programme requirements – may make a different method more
appropriate.

3. The Method Is Defined but the Production Rate Is Optimistic

The method is correctly defined but the production rate is based on best-case conditions
rather than realistic conditions. The programme is too short and the estimate is too low.

4. The Method Is Defined but Not Communicated

The method is defined at bid stage but not communicated to the delivery team. The delivery
team uses a different method. The programme and estimate are based on a method that is
never executed.

5. The Method Is Not Updated When Conditions Change

The method is defined at bid stage and never reviewed. When conditions change – different
ground, different access, design changes – the method must be updated. If it is not, the
programme and estimate will diverge from reality.

6. The Method and the Programme Are Inconsistent

The method statement describes one approach and the programme assumes another. The
programme shows a duration that is inconsistent with the production rate of the defined
method. The estimate is based on a different plant mix from the one in the method statement.

---

Summary

The construction method is the most fundamental decision in construction planning.
It determines the duration, the cost, the risk profile, the programme logic and the
quality outcome of every work package. The key principles are:

• Always define the construction method before building the programme or the estimate
• Evaluate all feasible methods against the specific conditions of the project
• Choose the method that best satisfies the technical, programme, cost, risk,
  safety and environmental criteria
• Define the method in detail – plant mix, crew (FMU), production rate, sequence
  and constraints
• Document the method in a method statement that is consistent with the programme
  and the estimate
• Communicate the method to the delivery team
• Update the method when conditions change

A project that starts with a well-defined construction method for every major work
package will have a programme that is achievable, an estimate that is reliable and a
delivery team that knows exactly what they are doing. A project that does not will
have none of these things.

---

Need Help Defining or Evaluating Construction Methods?

We work with contractors, owners and project teams on construction method selection,
methodology-led planning, Efficient Construction Cost (ECC) modelling and method
statement development. Our approach starts with how the work will actually be built –
and builds the programme and estimate from there.

Use the form below to discuss your project.