BIM Assignment Arrives With Missing Information

1 Introduction
2 Confirming the scope and deliverable
3 Checking the available information
4 Raising clarification questions
5 Progressing work while information is outstanding
6 Developing the skill
7 Related articles on Designing Buildings

[edit] Introduction

Early in a career in building information modelling (BIM), it is common to receive a modelling task for which some of the information needed is incomplete. For example, a newly appointed modeller may be given a floor plan and asked to model a small office area within a few days. The plan shows an opening in a wall but gives no width, and a note refers to a drawing that cannot be found. The deadline is clear, but the information needed to meet it is not.

An effective response involves establishing what the team actually needs, checking the information already available, and raising specific questions early. These steps can be practised by graduates before they join a project, and the same approach applies to experienced engineers and technicians who are starting to receive work through a shared model or common data environment (CDE).

[edit] Confirming the scope and deliverable

An instruction such as "model the office area" can mean several things. The team might need a simple layout to discuss with the architect, a model that another discipline can use as a reference, or a dimensioned drawing sheet. Each outcome requires different checks and a different amount of time, and the level of information need for the task should be agreed before work starts. A specific question, such as "For Friday's review, should I submit a model of rooms 201 to 204 and one marked-up plan?", gives the person assigning the work something concrete to confirm.

Where the task has been issued through a project platform, the agreed scope should be recorded there so that everyone can refer to it later. If two people assign related work, it should be confirmed which request takes priority, and both should be told what has been agreed. The method of handover should also be clarified, as some teams expect a file in a review folder while others expect a link to a specific view or an exported sheet. Knowing this in advance avoids preparing material that has not been requested.

[edit] Checking the available information

The first step is to review the drawings and notes supplied with the assignment. The title block identifies the drawing number, revision and status, and the missing information may appear in a dimensioned detail or a schedule. Where the project uses a CDE in accordance with ISO 19650, the status of each information container should be checked, as information in the work in progress or shared states may still be subject to change and may not be suitable for the intended use. A recently uploaded drawing may still be under review.

A simple record should be kept of what has been checked, for example: "Plan A-204, revision P03, shows the opening. Detail A-507 does not give its width." This gives the reviewer a starting point and saves others from repeating the search. Where two references give different values, both values and their sources should be recorded, so that the project lead can decide which document takes precedence or ask the responsible designer to confirm the design intent.

[edit] Raising clarification questions

A request such as "Please check the opening" leaves the reader to work out what is being asked. A more useful message identifies the location and the decision required, for example: "Could you confirm the clear width of the opening between rooms 203 and 204? Plan A-204 shows the opening, but I could not find a dimension in the referenced detail. I have marked the location on the attached plan."

The message should include the floor, room or grid reference and the exact information needed. A screenshot can be helpful if it shows enough of the surrounding area for the reader to orientate themselves. If the answer affects the handover, the message should say when it is needed and what can be completed in the meantime.

On some projects, missing or conflicting information must be raised through a formal request for information (RFI). The project's procedure should be followed, including who is authorised to raise an RFI. An informal internal clarification and a formal RFI serve different purposes, depending on who needs to answer and how the decision must be recorded.

[edit] Progressing work while information is outstanding

While waiting for an answer, the parts of the model based on confirmed information can be completed. The requested views can be prepared, the extent of the unresolved area identified, and the outstanding question kept visible in the task notes or issue log. If a supervisor approves a temporary dimension for an early review, it should be recorded as provisional and its locations identified so that it can be updated later.

A short progress update helps the project lead see what remains, for example: "Rooms 201 to 204 are modelled. The opening between rooms 203 and 204 is awaiting confirmation. The review plan is ready, with that location marked." The lead can then decide whether the package can be reviewed before the missing information is received.

When the answer is received, it should be checked for knock-on effects on other work. A change to the width of an opening could affect adjacent dimensions, door schedules or annotations on the review sheet. These should be updated and the query closed in the agreed location so that the team has a traceable record of the decision.

[edit] Developing the skill

This skill can be practised using a simple floor plan from which one dimension has been removed and to which a conflicting note has been added. Working within a fixed time, such as 25 minutes, the trainee identifies what can be modelled, writes a clear clarification request, and prepares a short status update. A second person then reads the message without seeing the model. If they can locate the problem and understand the decision required, the message is effective.

Exercises of this kind build on what engineering and architecture graduates already know about drawings and design intent. When assessing BIM training, it can be useful to ask how often learners work with incomplete information, how they are taught to document assumptions and prepare a handover, and how their queries are reviewed.

On a real project, incomplete instructions are usually manageable once the team knows exactly which decision is outstanding. Confirming the required outcome, checking the references and raising open points early allow the reviewer to see what is ready, what needs a decision, and what will happen once the answer is received.