LIBRARY // ACCURATE MODELLING AND RESEARCH

Surveying and Modelling Existing MEP Services

Existing services are often hidden, undocumented or both. Surveying them properly avoids surprises during strip-out.

Refurbishment projects often need information about existing MEP services. Services may be retained, modified or removed, and new services must fit around them. Surveying and modelling existing services helps design teams make informed decisions.

What can be surveyed

Laser scanning captures visible services, such as:

• Ducts and pipes in plant rooms and exposed areas
• Cable trays and containment
• Equipment and plant
• Risers, if accessible

Hidden services, such as those above closed ceilings or within walls, need opening up or other investigation methods.

Services surveys

Specialist services surveys identify systems, condition and function, not just geometry. They may include:

• Equipment details and condition
• System types and routes
• Capacity and performance
• Compliance issues

Combine geometric surveys with services surveys for a fuller picture.

Level of detail

• Main plant and routes for planning
• Detailed geometry for areas where new services will interface
• Simplified representations elsewhere

Modelling every small pipe is rarely necessary.

Modelling in BIM

Existing services can be modelled in Revit or other tools, using point clouds as reference. Mark existing elements clearly, using phases or parameters, to distinguish them from new work.

Uncertainty

Note where information is uncertain, such as services assumed from partial views or old drawings. This helps designers understand risk.

Hidden services

Ground-penetrating radar, cable locators and other methods can help detect buried or hidden services. Intrusive investigations may be needed for critical areas.

Hazardous materials

Older services may contain hazardous materials, such as asbestos insulation. Surveys should be carried out in accordance with relevant regulations, and specialists involved where needed.

Coordinating new services

With existing services modelled, new designs can be checked for clashes and connections. This is especially useful in congested plant rooms.

Update during works

As works open up spaces, update the model with newly discovered services.

Record information

Provide updated records at completion for future maintenance.

Confidence levels

Mark existing services as surveyed, traced from records or assumed. This helps designers judge risk, for example before routing new ductwork through a ceiling void that hasn't been opened up.

1. 01What can be surveyed
2. 02Services surveys
3. 03Level of detail
4. 04Modelling in BIM
5. 05Uncertainty
6. 06Hidden services

Live services

Existing services may be live. Surveys and opening-up should follow safety procedures and the building's permit-to-work arrangements.

Accurate information on existing MEP services reduces surprises and helps refurbishment designs fit the building as it really is.

If your team needs extra production capacity for work like this, take a look at our Architectural production services, or tell us about your project.