One LLM for the firm: why BIM teams must set the AI standard
Stop personal ChatGPT, Claude and DeepSeek accounts on project work. Put the firm on one BIM-controlled LLM, starting with Copilot and Claude Cowork.
BIM teams already write standards for software, naming, the common data environment and model quality. Artificial intelligence now sits in that same category. If the firm does not define how AI is used, staff will define it themselves — usually on a personal OpenAI, Anthropic or DeepSeek account, with a client PDF sitting in the prompt box.
That is not innovation. It is an uncontrolled information exchange.
Treat AI like any other project system
A personal chatbot is convenient. It is also invisible to the project record. There is no appointment, no access control, no audit trail and no agreed retention. The person who pasted the specification may leave next month. The prompt history stays on someone else’s laptop, or on a consumer account the firm cannot close.
BIM managers would not accept a private Dropbox as the CDE. They should not accept a private large language model as the research assistant.
The standard should be simple: project work happens inside a firm-controlled LLM. Personal consumer accounts are not an approved tool.
What goes wrong with personal accounts
Staff do not set out to leak a project. They ask a model to rewrite a scope, summarise a clash report or draft a BIM execution plan. The file still contains the client name, the site, the cost plan or a unique coordination issue.
Consumer tools are built for individuals. Firm tools are built for organisations. The difference is not the quality of the answer. It is who can see the prompt, how long it is stored, whether it can be used for training, and whether legal can produce the record if a client asks.
DeepSeek, a personal ChatGPT login and a free Claude account all fail that test in the same way. They are not in the firm’s tenancy. The BIM team cannot turn them off, review their use or prove that client data stayed inside the appointment.
If you would not upload it to an unmanaged cloud folder, do not paste it into an unmanaged model.
The BIM team should own the standard
IT can procure licences. Legal can review terms. The BIM team should write the working rule, because they already decide how information moves.
The standard should cover:
- Approved tools and who may use them
- What project information may be submitted, and in what form
- What must be stripped or anonymised first
- How outputs are checked before they enter a model, schedule or client document
- How use is logged, reviewed and withdrawn when someone leaves
Publish it the same way you publish a naming convention. Train it. Audit it. Do not leave it as a slide from last year’s digital strategy.
Put everyone under one controlled LLM
“One LLM” does not mean one product forever. It means one controlled environment. Every approved tool sits under the firm’s identity, contracts and logging. Staff should not have to choose between getting work done and following policy.
When the approved path is slower or worse than a personal account, people will route around it. The BIM team’s job is to make the official path the easy path.
Start with Copilot
For firms that are just beginning to use AI, Microsoft Copilot is the practical first standard.
Most AEC offices already live in Microsoft 365. Copilot sits next to Word, Excel, Outlook, Teams and, in many cases, the same identity used for the CDE. That gives the firm a single place to switch licences on, apply data protection, and keep work inside a commercial agreement.
Copilot is also familiar. Coordinators, project managers and technicians can ask for a meeting summary or a first draft without learning a new workspace. That breadth matters more than peak model performance in the first year.
Use Copilot to establish the habit: AI is available, it is official, and it is not a side account.
Add Claude Cowork when the team is ready
More advanced BIM teams will outgrow a general assistant. They need longer threads, structured document work and agent-style help against approved project material — comparing standards, drafting information requirements, or working through a package of meeting notes and model reports.
Claude Cowork is built for that kind of work. It is a stronger fit once the firm already has a policy, a tenancy and a clear list of what may be uploaded. It is not the first tool to hand a 40-person office with no AI standard.
Treat Cowork as a controlled specialist environment, not a shadow IT experiment. The BIM team decides who gets it, which project spaces it may see, and how outputs re-enter the CDE.
A balance of both usually works best
Forcing every task through one product creates the same problem as banning AI entirely. People will find a faster unofficial option.
A workable stack for most firms looks like this:
- Copilot as the default, everyday assistant inside Microsoft 365
- Claude Cowork for BIM, digital delivery and information-management teams doing deeper work
- One policy that names both, forbids personal consumer accounts, and says what client information is allowed
The BIM team remains the owner. IT keeps the licences and logs. Legal keeps the contracts. Staff keep a route that is good enough that they do not need ChatGPT on a phone.
What to do this month
Write the rule in plain language. Name the approved tools. State that personal OpenAI, Anthropic and DeepSeek accounts are not permitted for project or client information. Put Copilot in place for the wider firm. Give the BIM team Claude Cowork where the work justifies it. Then review use the way you already review model quality: regularly, with evidence, and with a path to correct it.
AI will keep changing. The standard should not. Project information stays in systems the firm can see, close and explain.
Frequently asked questions
Why can't staff just use their own ChatGPT or Claude accounts?
Personal accounts sit outside the firm's contracts, logging, retention rules and data residency. Anything pasted there can leave the project record and, in some cases, be used to train a consumer model.
Who should own the AI standard?
The BIM or digital delivery team, with IT and legal. BIM already governs how project information is created, stored and exchanged. AI is another information exchange.
Should a firm pick Copilot or Claude Cowork?
Start with Copilot if the firm is new to AI. Add Claude Cowork when teams need longer, more structured work on approved project data. Most firms end up using both under one policy.
What should never go into a public chatbot?
Client names, drawings, models, specifications, commercial terms, passwords, personal data, and any file that would be restricted in the CDE.