When people think about construction projects, the focus usually falls on the visible stages. Planning approval. Construction starting on site. The completed build.
In reality, one of the most important stages happens long before work begins.
Tender stage is where the design information is issued to contractors so they can accurately price, programme and assess the project before entering into a contract. At this point, drawings, specifications, survey information and supporting documents all come together to form the basis of the construction package.
While it can appear to be a straightforward pricing exercise from the outside, tendering is really about reducing uncertainty.
The quality of the information issued at this stage has a direct impact on cost certainty, programme certainty and coordination throughout the build. Contractors can only accurately plan for the information they have in front of them. If key details are missing, unclear or introduced later in the process, it almost always results in additional cost, additional coordination and pressure on programme once works are underway.
Why Tender Stage Is So Important
Earlier design stages, particularly planning, are often focused on overall layout, external appearance and securing approvals. Tender stage is different.
This is where projects move into technical detail. Contractors need enough information to properly assess the scope of works, understand buildability and identify potential risks before arriving on site.
That process takes time. Once a tender package has been issued, contractors will typically review drawings, assess specifications, speak with subcontractors and visit site before returning a formal price. Those site visits are particularly important because they allow contractors to assess practical considerations that cannot always be understood from drawings alone.
Access routes, material storage, parking, demolition sequencing and site setup all influence how a contractor approaches the works and ultimately how the project is priced.
The Impact of Missing Information
The phrase “the devil is in the details” is used frequently in construction, and tender stage is where that becomes most relevant.
One of the most common issues on projects is specialist or client-specific information being introduced after tender stage has already been completed. On complex residential adaptation projects, this can include automation systems, specialist equipment, sensory installations or additional care requirements.
These items rarely operate in isolation.
For example, introducing automation late in the process can affect electrical design, ceilings, joinery packages and specialist equipment coordination simultaneously. While those additions may appear manageable in isolation, they often create significant coordination requirements once construction is underway.
This is why establishing the full scope as early as possible is so important. The earlier information is identified and included within the tender package, the greater the level of certainty moving forward.
Cost Certainty and Variations
There is often a misconception that producing a more detailed tender package increases costs unnecessarily. In reality, it usually provides greater financial control over the lifespan of the project.
If contractors fully understand the scope of works from the outset, they are less likely to encounter elements during construction that have not been accounted for. That significantly reduces the risk of variations later in the contract.
Provisional sums are often used during tender stage for items that have not yet been fully selected, particularly finishes. These allowances provide flexibility while still allowing reasonable budgets to be included within the contract. Once final selections are made, actual costs can then be assessed against those allowances.
The difficulty arises when major items are introduced after contracts have already been agreed. At that point, changes become more disruptive because additional pricing, coordination and programme adjustments are often required simultaneously.
Survey Information and Hidden Risk
Refurbishment projects always contain an element of unknown risk because parts of the building are concealed until demolition begins.
Until floors, ceilings or walls are opened up, contractors cannot always fully understand structural conditions, foundations or hidden defects within the property. This makes survey information a critical part of the tender process.
Asbestos surveys, timber and damp investigations and ground investigations all help reduce uncertainty before works begin. They allow contractors to understand the likely condition of the building and include appropriate allowances within their pricing.
Ground investigations are particularly important on extension projects because foundation design is heavily influenced by soil conditions and existing site constraints. Likewise, timber and damp surveys can identify structural concerns or infestations that may have a significant impact on the scope of works later on.
The more information available before tender stage, the more accurately contractors can assess risk and programme the project accordingly.
The Importance of Clear Drawings
From an architectural perspective, a strong tender package is not about producing more drawings. It is about producing clear drawings.
Contractors need information that clearly communicates the design intent, quantities and construction requirements without creating unnecessary confusion. Trying to place too much information onto a single drawing can often make interpretation more difficult rather than easier.
This becomes particularly important on specialist adaptation projects where multiple consultants and suppliers may all be contributing information simultaneously. Occupational therapists, hydrotherapy consultants, sensory specialists and equipment suppliers may all influence different parts of the design.
Coordinating those requirements before tender stage is essential because many specialist systems interact directly with the building fabric and wider construction packages.
Coordination Across the Wider Team
One of the realities of complex residential projects is the number of people involved. In many cases, the wider client team can be larger than the construction team itself.
That level of involvement creates coordination challenges throughout design and construction, particularly where multiple recommendations are feeding into the project at different stages.
From our perspective, communication and contract administration are key to managing that successfully. Keeping the wider team informed, reviewing recommendations collaboratively and updating drawings as decisions evolve all help maintain continuity between design, tender and construction stages.
Tender stage should not be viewed as a standalone exercise. It forms the foundation for everything that follows.
Why It Matters to Client Teams
For case managers, deputies and solicitors involved in these projects, tender stage directly affects the client experience once construction begins.
The more detailed and coordinated the tender package is, the greater the level of certainty around costs, programme and delivery moving forward. While construction projects will always contain variables, particularly within existing buildings, a well-developed tender process significantly reduces avoidable surprises later down the line.
Ultimately, successful tendering is about creating clarity before works begin.
Because in construction, it is rarely the large headline decisions that create pressure later on. More often, it is the smaller details that were never fully resolved at the start.
