The Preconstruction Phase: A Deep Dive into the Pre-con Process

Preconstruction is the strategic phase of a construction project that bridges the gap between the initial plans drawn up in the pre-development stage and the physical activities associated with work on site. This phase refines broad project ideas into concrete plans that balance cost efficiency and quality while identifying and mitigating potential risks.

What Is Preconstruction?

Preconstruction also fulfils duties set out in legislation such as the Construction (Design and Management) Regulations 2015 (CDM 2015). Early engagement helps clients, designers and main contractors (MCs) satisfy legal obligations, secure Planning Permission and Building Regulations approval, and control costs long before the first spade enters the ground.

Defining Preconstruction

The essence of preconstruction is to transform broad strokes into fine details. You may find project managers collaborating closely with architects to fine-tune designs, cost planners developing detailed budgets, or construction managers identifying potential safety hazards and devising robust mitigation plans.

Below, we examine why project owners and contractors focus so heavily on a thorough preconstruction process when aiming for a successful construction phase.

Importance of Preconstruction

Preconstruction is the foundation that takes a construction project from idea to built reality. During this phase, owners, project managers, architects, engineers and other stakeholders tackle important questions, including:

• Have we fully refined the design to account for all practicalities of construction?
• Which main contractor is most suitable for our specific project requirements?
• How do we efficiently organise resources and mobilise for construction?
• How can we best anticipate and mitigate potential risks, both in terms of safety and cost?
• What are the realistic timelines—or programmes—for each phase of construction?
• Have we obtained all necessary permits, including Planning Permission and Building Regulations approval?

Addressing these questions enables the project team to avoid roadblocks and ensure that the project gets off to a smooth start.

The work that happens during preconstruction sets the stage for later success—or failure. Projects with shaky budgets, poor risk-mitigation tactics, incomplete site assessments and negligent designs frequently break ground, but they rarely make it through construction unscathed. Variation orders, financing problems and differing site conditions are virtually guaranteed to arise. Experienced developers and construction professionals know that projects live and die according to preconstruction management.

The Preconstruction Team

Before preconstruction begins, the client or developer assembles the team that will prepare the project. The actual professionals and companies involved will vary by project type, size and complexity.

Owner or Developer

Sets the objectives, budget and success criteria. Larger developers may appoint an owner’s representative or project manager to steer the process.

Design Team

Responsible for designing every detail of the project.

• Architects / Lead Designers – develop preliminary and detailed designs.
• Civil Engineers – provide site analysis (drainage, access, surveys).
• Structural Engineers – ensure the structure is sound.
• MEP Engineers – design services and building systems.

Main Contractor / Construction Manager

Clients often bring in a main contractor (MC) early to advise on buildability, cost and programme. (For simplicity, we use the term MC to include roles a construction manager may perform.)

Specialist subcontractors—plumbing, electrical, HVAC—may also contribute during preconstruction.

This is by no means an exhaustive list. Many other players may be involved, including legal counsel, environmental consultants, government representatives, and more. A savvy owner will identify the knowledge gaps or needs as they build the preconstruction team to ensure they hire professionals with the right experience and skill sets for the job. 

Key Activities in Preconstruction

During preconstruction, the project owner assembles the project team that will produce with architects, engineers, contractors, and other construction professionals to take a project from conception to construction. Before preconstruction begins, a project owner will have already completed key predevelopment tasks like feasibility studies, site assessment, land acquisition, financing, and preliminary design. 

At that point, the focus shifts to further developing the design, selecting contractors, accounting for risk, and mobilising for construction. To kick off this phase of a project, the owner or project manager often holds a preconstruction meeting with the key stakeholders to establish roles and responsibilities and clarify expectations. 

We explore each activity in more detail below.

Design Development

Design development is the process of refining the preliminary concept into a collection of project specifications and drawings that detail the design, materials, methods, and standards required for construction. This process involves the collaboration of architects, engineers, interior designers, and potentially contractors with certain project delivery methods, like design-build (DB). Design development finds a balance between creative vision and technical or financial feasibility through several stages: architectural design, engineering design, interior design, and design review.

The architectural design phase involves creating drawings that visually depict the project’s concept, layout, and structure. The design team then expands upon these schematics to develop detailed construction drawings. These documents provide in-depth information about the design and are essential in guiding the subsequent construction process.

Next, the engineering design process ensues. Specialists in structural, mechanical, electrical, and plumbing engineering ensure the building’s robustness, efficiency, and regulatory compliance. A key aspect of this phase is creating project specifications, which detail materials, standards, and methods for the project’s construction.

Interior design is an integral component of the design development phase as it pertains to crafting functional, aesthetically pleasing indoor environments. Here, the focus is on the eventual occupant’s experience, comfort, and productivity within the space.

Design Review

Throughout the design development phase, an iterative process of design review and revisions unfolds. Stakeholders, including the project owner, potential tenants, regulatory authorities, and community representatives, can provide valuable input, leading to design enhancements. This process is instrumental in achieving a design that aligns with the project’s budget, constraints, local regulations, and objectives.

Contractors can also engage in design review as a design-assist contractor.  This gives the architect and project owner valuable input, such as the constructability of the design, installation, and cost estimating.

Many projects use value engineering during the design development phase. Value engineers use a methodical review process to identify and remove unnecessary costs while ensuring the design meets the desired quality and functionality. Budgetary constraints inform and shape the design process from the beginning, ensuring the final design is economically viable without compromising on value.

Another increasingly common aspect of modern design development is the creation of a Building Information Modeling (BIM) model. BIM is a 3D model-based process that gives architecture, engineering, and construction (AEC) professionals the tools to efficiently plan, design, construct, and manage buildings and infrastructure. 

A BIM provides a digital representation of the building’s physical and functional characteristics, enabling teams to anticipate and address potential issues before construction begins. BIM is a potent tool that enhances visualisation, improves collaboration, and promotes better decision-making throughout the construction process.

At the culmination of the design development phase, the project team will have a comprehensive design, constrained and honed by budget considerations, regulatory compliance, and stakeholder feedback. With a solid design in place, the project owner is ready to select contractors, moving closer to the construction process. 

Contractor Selection

After finalising the project’s design, a project owner will seek to find a qualified main contractor to build the design. Typically, this involves using some combination of a Request for Quotations (RFQ), or a Request for Proposals (RFP).

For contractors, this phase requires an understanding of the project (typically a short amount of time) to provide detailed cost estimation, and the development of a competitive bid.

The construction bidding process often begins with the owner issuing an RFQ or an RFP, soliciting contractors to demonstrate their ability to carry out the project based on their past performance, expertise, and financial stability. Contractors must have a deep understanding of the project’s requirements and express their qualifications — often related to a specific proposal, record of past successful projects, safety record, and financial stability. 

Depending on the type of project, the goals of the owner, and existing relationships with contractors, the owner can choose from several different types of bidding. While open bidding is typically required on public projects of a certain size, owners on private commercial projects often prefer selective or negotiated bidding. This allows them to approach contractors they trust or negotiate directly with a preferred contractor, often ensuring a higher quality of work. As a contractor, being on the shortlist for selective bidding often indicates a strong reputation and trust in the industry.

Cost estimation is an essential part of a contractor’s process of writing a bid. Contractors analyse the scope of the project, the labour required, the cost of materials, equipment, overhead, contingency, and profit margin to arrive at an accurate cost estimate. A well-crafted cost estimate can demonstrate a contractor’s understanding of the project and their ability to deliver it within the owner’s budget.

Once the cost estimate is complete, the contractor creates a bid that outlines their proposed approach, cost, and timeline for the project. It should detail how they plan to execute the project, their estimated costs, and when they expect to complete the project. 

During bid evaluation and leveling, the owner scrutinises the bids to select the best contractor for the project. They compare bids on various factors, such as cost, experience, proposed schedule, and proposed approach — though price tends to be the definitive factor. Leveling the bids ensures a fair comparison by normalising for differences in how contractors might have interpreted the project scope.

Finally, the project owner awards the contract to a specific contract and contract negotiation occurs. This involves finalising the contract’s terms and conditions, such as payment terms, project timeline, and scope of work. It’s a chance for both parties to align their expectations and agree on how the project will proceed.

Risk Analysis and Mitigation

Risk analysis and mitigation help the project team anticipate potential issues, assess their impact, and develop plans to mitigate negative effects on the project. The main contractor or construction manager typically performs these activities to plan for cost control, site-specific safety measures, and quality control.

Risk analysis starts with risk identification and assessment. This involves a systematic process to detect potential risks that could impact the project and evaluate their likelihood and possible impact. This comprehensive risk review covers everything from budget and schedule risks to design, legal, regulatory, safety, and environmental risks.

Next, cost control planning involves developing strategies to monitor and control costs throughout the project. This goes beyond merely tracking expenses — it encompasses forecasting, variance analysis, and change control to keep the project within budget and prevent cost overruns. By controlling costs effectively, the project team can ensure that the project’s financial performance aligns with the budget — and maintains profitability for all parties.

Site-specific safety planning is the process of developing a safety plan that takes into account the unique conditions and potential hazards of the construction site. This safety plan is designed to prevent accidents, ensure the wellbeing of workers, and meet regulatory requirements. It includes protocols for proper use of safety equipment, handling hazardous materials, emergency response, and training.

Quality control planning involves the creation of a plan to maintain quality standards throughout the project. It aims to prevent defects, reduce rework and ensure that the final project deliverables align with the project’s objectives and the owner’s expectations. This might involve setting quality targets, defining inspection and testing procedures, and establishing a process for handling defects and changes.

Finally, risk response planning involves preparing strategies to deal with identified risks. The team might choose to avoid, transfer, mitigate, or accept risks, depending on their potential impact and the project’s risk tolerance. This response planning helps ensure the team is prepared to proactively address risks and maintain control over the project’s outcomes.

Project Programme

The MC produces a detailed project programme that lays out the timeline of all tasks necessary to complete the project, taking into consideration dependencies (i.e. tasks that must be finished before others), the resources required, and potential risks. 

The schedule serves as the project’s roadmap, guiding all involved parties throughout the project’s lifecycle.

A well-planned project schedule begins with the development of a Work Breakdown Structure (WBS). This process breaks down the project’s scope into manageable tasks, providing a clear foundation for the programme and resource allocation. Each activity is then linked with the necessary resources and dependencies to form a cohesive project timeline.

Identifying the critical path involves outlining the sequence of dependent tasks that takes the longest time to complete. As these tasks directly impact the project’s finish date, any delay on the critical path will inevitably delay the whole project. Understanding the critical path allows project managers to focus on managing these crucial tasks effectively.

Resource allocation planning is the process of assigning resources — such as labour, materials, and equipment — to each task in the programme. This ensures that the necessary resources are available when needed, preventing schedule delays due to resource shortages.

Risk assessment in scheduling involves identifying and evaluating potential risks that could impact the project schedule. This could include unforeseen delays, changes in scope, or resource availability issues. Risk assessment helps the team develop contingency plans and buffer times in the schedule, allowing for more accurate and realistic project timelines.

The team can visualise the project schedule using tools like Gantt charts or network diagrams. These visualisations provide a clear picture of the project timeline, task dependencies, and progress, making it easier for all stakeholders to understand the project’s status and expectations.

Finally, the project team chooses an appropriate scheduling methodology. Methods like the Critical Path Method (CPM) or Program Evaluation and Review Technique (PERT) provide structured frameworks for creating and managing the project schedule.

Permitting

Obtaining proper approvals ensures the project complies with all relevant UK legislation and codes.

Failure to obtain these approvals can halt works and incur penalties.

Construction Mobilisation

Construction mobilisation marks the transition from preconstruction to the physical start of work on site. This process involves preparing the construction site, assembling the construction team, arranging necessary equipment and materials, setting up site facilities, and ensuring proper safety measures are in place.

Site preparation is the first step in mobilisation. This typically involves clearing the site, removing any existing structures, grading the site for drainage, setting site boundaries, preparing access for equipment and materials, and implementing necessary erosion and sediment control measures. This process prepares the ground for the upcoming construction activities and helps to minimise potential site-related risks.

Next, team mobilisation takes place. Key members of the construction team, such as the project manager, site supervisor, safety manager, and various trade personnel, are assembled on site. These individuals are instrumental in coordinating and managing construction activities and ensuring a safe and efficient work environment.

In tandem with team mobilisation, the project sees the arrival of equipment and materials. The necessary construction machinery and equipment are brought to site, and arrangements for material delivery are coordinated to align with the construction schedule. Proper planning here ensures that work can proceed without unnecessary delays.

Site facilities setup involves establishing temporary facilities needed to support construction activities. This can include site offices, storage areas, worker facilities like restrooms and break areas, and any necessary safety installations. 

Lastly, the team will put in place necessary safety measures and procedures to protect workers and the public. This includes safety signage, fencing to secure the construction site, and the provision of personal protective equipment (PPE) for the workers. A site-specific safety plan is implemented, which outlines procedures for safe work practices, emergency response, and ongoing safety training.

Pre-Construction Information & UK Regulations (CDM 2015)

Under the Construction (Design and Management) Regulations 2015, the client and Principal Designer must compile a Pre-Construction Information (PCI) pack outlining site risks, surveys and welfare arrangements before work starts. Sharing robust PCI enables the Principal Contractor to prepare a CDM-compliant Construction Phase Plan and enhances overall site safety.

Typical UK preconstruction deliverables include:

• RIBA Stage 4 design set
• Cost Plan Level 3
• Project risk register
• Pre-Construction Information (PCI) pack
• Draft Construction Phase Plan

Site Safety in Preconstruction

Early hazard workshops allow the project team to eliminate or design-out risks and set measurable safety targets. Aligning with HSE guidance during preconstruction reduces incident rates once construction is under way.

Transitioning Seamlessly from Preconstruction to Construction

The preconstruction phase is a critical juncture to lay the groundwork for successful project completion. Elements like design development, contractor selection, risk analysis, project scheduling, permitting, and construction mobilisation require careful planning, rigorous analysis, and thoughtful decision-making.

Effective preconstruction mitigates risk, boosts programme efficiency and creates a data trail that improves forecasting across your portfolio. A single project-management platform such as Procore maintains this data from concept to handover, providing one source of truth for site and office teams alike.

With this information at their fingertips, project teams can stay on track, maintaining timelines and budgets while delivering the quality specified in the project plans

Frequently Asked Questions

What happens during preconstruction?
The team finalises designs, agrees budgets, secures permissions and prepares the site.

How does preconstruction differ from construction?
Preconstruction focuses on planning and approvals; construction executes the approved plan on site.

What is a Pre-Construction Phase Plan?
A document prepared by the Principal Contractor under CDM 2015, setting out site-specific safety arrangements before work starts.

How long does the preconstruction phase take?

Most UK commercial projects spend 10–20 % of the total programme in preconstruction, but complex schemes (e.g. data centres) may require up to 12 months.

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