Plain Language Questions (PLQs) are posed by a client/employer at various stages throughout a construction project and responded to by the supplier(s).
The British Standards Institute defines PLQs as:
Questions asked of the supply chain by the employer to inform decision-making at key stages of an asset lifecycle or project from PAS 1992-3. A request for information that is expressed in simple, easy-to-understand terms from BS 8536-1.
In a nutshell, PLQs are a way of communicating a client/employer's broad information requirements and suppliers will use data taken from a range of sources, including models, to provide answers. These PLQs inform key decisions and, ultimately, allow the client/employer to decide whether or not to proceed to the next project stage.
How do PLQs inform the development of information on a project?
As a project progresses the level of information will typically increase, steadily, in line with the Plain Language Questions that have been posed.
In some areas the level of information may also decrease as extraneous information is jettisoned when decisions have been made and very specific solutions have been determined.
When do PLQs get answered?
Plain Language Questions need to be considered throughout all stages of a construction project.
The NBS BIM Toolkit includes a function for drafting and allocating PLQ to project stages and appointments.
What do PLQs actually look like?
Some examples of PLQs at each project stage might include:
| Stage |
Example PLQs |
| Stage 00 - Strategy |
Have stakeholders' needs been captured? How will security requirements be met? Have lessons been learned from previous projects? |
| Stage 01 - Brief |
How are stakeholder needs captured? How will BIM be managed and exploited in this project? What physical constraints are there on and around the site? |
| Stage 02 - Concept |
Can the services and structure be combined in the available 3D volumes? Has the asset been designed for manufacture and assembly? How will client specific performance requirements be met? |
| Stage 03 - Definition |
Does the design meet volumetric requirements? Does the asset comply with a stated regulation (such as Part L)? Does the design information comply with information security management plans? |
| Stage 04 - Design |
Have any changes in operational requirements been taken into account? What is the status of required consents and agreements? |
| Stage 05 - Build and Commission |
Do systems work correctly? How will safety and environmental protection be assured? How will the asset be operated? |
| Stage 06 - Handover and Closeout |
Does the facility meet the brief? Has the required health and safety information been made available? Have measures to manage the AIM been put into place? |
| Stage 07 - Operation and End of Life |
How do the specific products/ elements perform? |
The BIM Task Group site contains a set of Plain Language Questions categorised across seven project stages.
These PLQs were created by the Ministry of Justice for use on their projects and the accompanying descriptors show where the answers to the questions are likely to be found.
Where do PLQs fit in a BIM workflow?
PLQs ultimately describe contract deliverables and therefore should be included within the Employers Information Requirements (EIR).
The EIR defines the information required by the employer (from their own team and the supply chain) in respect of the development of the project and/or the operation of the completed built assets.
Extracts from the EIR will feature in procurement documents to inform contractors and consultants.
Prospective suppliers respond to the EIR in the form of a BIM Execution Plan which is supplied pre-contract award to allow responses (in terms of approach and capability) to be assessed.
To get the most out of the process the employer and suppliers should agree what data and other deliverables are required to answer the PLQs. These requirements are documented in the post-appointment BEP in the form of Task Information Delivery Plans (TIDP).
The project team will rise to the challenge of answering the PLQs, sharing data in the Common Data Environment (CDE), with information produced informed by the Level of Definition (LoD) for each project stage.
The response to the PLQs will be included in the data drop delivered to the employer at the end of the project stage but should not require a greater level of detail than would normally be available at a data drop. Depending on the nature of the questions being asked, the response will be provided in a combination of native file formats, PDFs and in the COBie format for data exchange.
At each stage clients/employers must validate the responses made to the Employers Information Requirements when determining whether to progress to the next project stage.
Why are PLQs important?
The development and exchange of data which can then be shared and re-used, making for improved decision making, lies at the heart of the BIM Level 2 proposition. By adopting this kind of process added value can be realised and efficiencies made.
PLQs help focus the efforts of all project participants on the kind of information that is required (and away from what is not) in order to meet the client's requirements.
Without PLQs the focus of a project would naturally gravitate towards the needs of regulatory requirements or to meet particular construction needs. PLQs help ensure that client needs remain front and centre, correcting this potential missalignment.
It's important to realise that PLQs are not a schedule of data drops, but rather an easily-understood way of communicating high-level information requirements. In response the supply chain can define and subsequently deliver data in response. PLQ deliverables will be a combination of data, documents and geometry that are all held in the Project Information Manual (PIM).
What makes a good PLQ?
The setting of PLQs is incredibly important and careful thought about what questions are posed will reap rewards throughout the project.
To be effective PLQs should relate to decisions required at a particular project stage or around key decision points. Bear in mind that generic lists of PLQs are unlikely to reflect organisational or project specifics and that tailored PLQs will get better results.
Where possible when posing a question think about phrasing that would allow for an industry standard response rather than disparate answers from a range of disciplines.
Never forget that the answers to questions are going to be found in a whole raft of assets - in models, reports, spreadsheets. Trawling through these sources, where data is often unstructured, can take time and make it difficult to determine whether a PLQ has been answered sufficiently, or indeed, at all. Where possible facilitate the answering of questions from structured data (such as that found in a COBie export or a model) instead.
A collaborative process will get better results - the employer working with the supply chain to determine how PLQs will be answered, agreement as to data formats ensuring that data can be shared and re-used, and sufficient time allowed for information collation ahead of key decision points. Developing a process that will supplied a consolidated and aggregated response to the PLQs rather than dealing with initial reports or data will undoubtedly speed decision making.
What to read next...
What is the Common Data Environment?
What is the common data environment or CDE on a construction project used for? Who contributes? Who is responsible? Who owns the information within? Why use a CDE at all? We explore the idea of a central information repository that is at the heart of BIM implementation.
What is the PAS 1192 framework?
The PAS 1192 framework sets out the requirements for the level of model detail (the graphical content), model information (non-graphical content, such as specification data), model definition (its meaning) and model information exchanges.
