Introduction

For corporate occupiers undertaking commercial fit-outs, the level of design detail established before a Design and Build (D&B) tender can influence cost certainty, technical specifications and project delivery. While D&B can offer programme efficiencies, the client’s requirements need to be sufficiently defined before contractors are invited to tender.

An appropriate level of Front End Engineering Design (FEED), often associated with the 30% design milestone, helps establish those requirements before contractor appointment. This guide examines the risks of an inadequately defined brief, the contents of a front-end design package and the steps involved in developing Employer’s Requirements, evaluating tenders and managing design integration.

The Bottom Line: Bridging the Gap Between Speed and Control

The Direct Answer

Front End Engineering Design (FEED), sometimes described as the “30% design” stage, helps establish the client’s design intent, technical requirements and performance criteria before a Design and Build (D&B) tender. It gives contractors a clearer scope against which to price and develop their proposals.

The appropriate level of front-end design will vary with the project’s complexity, operational requirements and risks. “30% design” is therefore a useful milestone rather than a fixed checklist applicable to every fit-out. The priority is to resolve the decisions that materially affect pricing, performance and delivery before contractors submit their bids.

The Value of Early Design Definition

An inadequately defined brief can produce tender submissions that appear comparable on price but differ substantially in scope.

For example, if a tender brief specifies the number of workstations but does not clearly define meeting room requirements, collaborative spaces or supporting facilities, contractors may make different assumptions about the layout, specifications and associated costs. This can make tender submissions difficult to compare, even when the proposed prices appear similar.

Similar issues can arise with electrical capacity, lighting controls, acoustic performance and access for maintenance. If the Employer’s Requirements do not establish a clear baseline, the client may only discover the differences during detailed design or construction.

The financial consequences can extend beyond the initial contract sum. An omitted requirement may become a variation. Equipment selected without considering maintenance access may be more difficult to service. A lower-cost specification may also carry higher operating costs over the period of occupation.

Front-end design helps make these decisions visible before tender. It allows the client to distinguish essential requirements from areas where contractors can propose alternatives, and to assess those alternatives against consistent criteria.

This longer-term perspective is explored in The Hidden Lifecycle Costs of Outdated Fit-Outs, which examines how fit-out decisions can affect operating costs and workplace performance beyond installation.

The Programme Advantage

Front-end design requires time before tender. The purpose of that investment is to reduce uncertainty at stages when changes can be more disruptive.

Resolving layouts, technical capacities and operational requirements early can reduce repeated tender queries and limit the need to revisit fundamental decisions after contractor appointment. It also gives bidders a clearer basis for preparing design, procurement and construction programmes.

For example, identifying a potential electrical capacity constraint before tender allows the team to investigate the implications and establish an appropriate pricing basis. Discovering the same issue after equipment selection may require redesign, additional approvals or procurement changes.

The aim is not to complete every detail before approaching the market. It is to balance upfront design effort against the value of greater scope certainty.

A coordinated front-end package should identify what has been agreed, what remains to be developed and which assumptions still require verification. This helps the contractor plan the next stage while giving the client visibility over the decisions that could affect delivery.

Benchmarking the Brief: What is in the 30% Design Package?

The content of a FEED package should reflect the project’s needs. A straightforward office fit-out may require a different level of definition from a workplace with significant equipment loads, extended operating hours or specialist environmental requirements.

The following illustrates how key requirements may be established before tender and subsequently developed by the D&B contractor.

Note: The allocation shown is illustrative. Actual deliverables, design verification, statutory submissions and approval responsibilities must be defined in the project scope and contract.

Strategic Recommendations: A Risk-Adjusted Framework

Step 1: Developing the Employer’s Requirements

The Employer’s Requirements translate the client’s business and operational needs into a basis for tendering, design development and delivery.

They should establish what the contractor must achieve, the constraints within which it must work and the evidence needed to demonstrate compliance. The level of detail should be proportionate to the consequences of an unclear or incorrect assumption.

Conservative Scenario

Begin with an initial assessment of existing site conditions, test-fit layouts and the key MEP performance requirements.

This establishes a baseline covering the intended use of the space, occupancy, essential specifications and known building constraints. Where information remains incomplete, identify the outstanding investigations and state how bidders should address them.

For example, if available electrical capacity has not yet been verified, the tender should make that uncertainty explicit. Allowing each bidder to adopt an undisclosed assumption makes comparison more difficult and can create disagreements later.

This approach keeps the initial design exercise focused while providing contractors with a clearer starting point.

Best-Case Scenario

Develop a more comprehensive front-end package appropriate to the project’s complexity.

This may include approved layouts, technical loads and capacities, MEP strategies, performance criteria and maintainability requirements. Coordinate these elements so that the spatial design supports the technical solution and the technical solution supports the intended operation.

Translate the agreed requirements into the Employer’s Requirements, including a clear record of design assumptions, interfaces and responsibilities. The resulting tender package should distinguish mandatory requirements from areas where alternative solutions will be considered.

The benefit is a more complete basis for pricing without removing the contractor’s opportunity to contribute practical design and construction expertise.

Step 2: The Tender Evaluation Process

A front-end design package creates a common benchmark, but the tender evaluation must test whether bidders have followed it.

A low price is only meaningful when the team understands what it includes, what it excludes and how the proposed solution will perform.

Conservative Scenario

Evaluate submissions against the defined scope, cost, programme and technical requirements.

Identify exclusions, qualifications and proposed substitutions that could affect delivery or future operations. Check whether allowances are realistic and whether the tender includes the work needed to meet the stated requirements.

A comparison schedule can help make these differences visible. Where clarification changes a bidder’s scope or price, record the adjustment before drawing conclusions about value.

This prevents a proposal with significant omissions from being treated as directly equivalent to a more complete submission.

Best-Case Scenario

Conduct a structured evaluation using the front-end documentation as the common benchmark.

Assess the contractor’s proposed methodology, technical solutions, programme commitments and compliance with the Employer’s Requirements. Tender interviews can be used to examine how the bidder intends to coordinate design, manage interfaces and demonstrate performance.

Pay particular attention to departures from the agreed specifications. An alternative may be beneficial, but its implications for capital cost, operating costs, maintenance and programme should be understood before acceptance.

The outcome should be an informed appointment based on the proposed solution and delivery capability, supported by a clear record of agreed scope.

Step 3: Post-Tender Design Integration

Contractor appointment does not end the need to manage design intent. The front-end package must be developed into coordinated information suitable for implementation.

This stage requires clear responsibilities, timely reviews and a controlled process for changes.

Conservative Scenario

Establish who is responsible for completing each part of the detailed design under the D&B contract.

Review key contractor submissions against the Employer’s Requirements and agreed specifications before implementation. The review points should reflect the project’s main risks, including critical systems, base-building interfaces and items that would be costly to change once installed.

Record comments and their resolution so that the team can distinguish an approved development from an unresolved departure.

Best-Case Scenario

Retain appropriate client-side project management and technical oversight throughout detailed design and construction.

Establish review and approval procedures that monitor compliance with the Employer’s Requirements and assess proposed changes before they affect procurement or installation. A change should be considered against its technical, financial, operational and programme implications.

Responsibilities for client-developed design must also be expressly addressed in the contract. The parties should understand which information the contractor must verify, which design obligations it assumes and how client-side reviews affect—or do not affect—those obligations.

This helps maintain continuity between the original requirements and the completed works while reducing ambiguity over accountability.

Conclusion: Control the Narrative Before You Build

Front-end design can strengthen D&B procurement by establishing clearer requirements before tender. It supports more meaningful comparisons between bids, greater clarity on cost and specification assumptions, and a more coordinated approach to delivery.

Early involvement of the project management team helps the client determine how much design definition is appropriate. It also supports coordination between operational stakeholders, technical consultants and the parties responsible for cost and programme.

The objective is not to pursue a design percentage for its own sake. It is to develop enough information to make sound procurement decisions and establish clear responsibilities between the client’s consultants and the D&B contractor.

The effectiveness of a D&B tender depends on both the procurement structure and the quality of the requirements issued to the market. Investing in appropriate front-end design can help reduce ambiguity, improve tender comparability and manage delivery risks.

Engineer Your Tender for Success

Preparing for a commercial fit-out? The Savills Project Management team can advise on front-end design requirements, D&B tender strategy and project delivery, helping align technical specifications, budgets and programme requirements with your project objectives.