BIM Explainer: Building Information Modelling in simple words

Inspired by Randall Monroe’s book ‘Thing Explainer'; Dan Rossiter has written a piece about Building Information Modelling (BIM) only using the 1000 most common words in the English language. BIM has been made harder than it is by people creating new words, confusing others, and even bending the truth. To prove that BIM can be easy, Dan wanted to show how simply it can be explained.

When we build, things can often go wrong. Ordered parts might be the wrong part, the wrong size or put in the wrong place. Things like this happen often and have happened for years. This is because when we share information we only share just enough, instead of sharing the information needed to help others. This means when we try and use this information, it’s often confusing or missing bits; meaning we make bad choices because of this bad information.

To make better choices using better information, we can use information management using Building Information Modelling (BIM). To make sure we all do it the same way, papers were made explaining how (ISO 19650).

First, owners need to work out what information they need by talking to the people who pay for, look after and use their builds (appraisal and need). They collect these needs and use them to ask for the right information:

  • What information they need (information requirements)
  • How much of this information they need (level of information need)
  • How they check information (acceptance criteria)
  • What they already have (existing information and share resources)
  • When information is needed by (key dates)

By agreeing what they need along with how they want information made (information standard, information production methods and procedures), as well as how to share (information protocol) owners are ready to ask a team to help (invitation to tender).

Each team that wants to help writes back (tender response) saying how they will make their information:

  • Who they will use (names of individuals)
  • Who does what bits (outline responsibility matrix)
  • What information they will create (information delivery strategy)
  • What changes they need to how information is set out (information standard, information production methods and procedures)
  • What tools they will use (schedule of software, hardware and IT)

By planning how they will make the information along with an understanding how good they are (capability and capacity assessment summary), how they will set up for the build (mobilzation plan) and how they will stop things going wrong (information delivery risk assessment) each team can be checked before they start.

After a team has won and are told they can build (appointment), they plan even more around who does what bits (detailed responsibility matrix), as well as how information is given to the owner and when (master information delivery plan).  The owner and their team then make sure everyone follows this plan (appointment documentation).

As they build and make information (collaborative production of information), everyone drawing, building or fixing (task teams) follow the agreed plan, checking that their information lines up (spatial coordination) with the work of others before sharing. After checking their work (check, review and approve) they share their information for everyone else to use, following the agreed plan on how to name and control information (common data environment). Before giving the owner this information (information model delivery), the team also checks the information (lead appointed party authorization) before it is also checked by the owner (appointing party acceptance).

At the end of the job (project close-out), the team shares all the information (project information model) with the owner. The owner keeps this information to check what their team did and uses some of it for looking after the build (asset information model). When needed, the owner may have to add new information after changes to the build (trigger-events) to keep their information right.

By following these steps, teams can work together to give an owner the information they need. By creating an agreed plan, there is a better chance that the parts ordered for the job won’t be wrong, the wrong size or put in the wrong place. That means less money and time are spent on problems, meaning more money and time to finish; best of all, a happy owner.


Dan Rossiter, Sector Lead at BSI

This text was originally published at