Integrated BIM MEP design: processes, advantages and solutions

Bringing together all elements of the architectural, plant and structural design in a single 3D model is the starting point for building an overview of the building-plant system and assessing the coherence of all construction elements prior to actual implementation. For many years, the architecture, engineering, and construction industries have relied on BIM, however, because of its benefits, BIM adoption is growing rapidly for plant projects as well.

In this article, we’ll provide some useful insights regarding how to work in BIM MEP and what it actually means.

BIM MEP design

MEP modelling definition

MEP design is the process of creating the 3D model of a plant project containing all the physical, technical and functional information relating to the mechanical, electrical and plumbing systems. MEP stands for Mechanical, Electrical and Plumbing.

The design of MEP installations consists of 3 main phases:

• modelling
• sizing and calculation
• cost estimating.

Working in BIM MEP, it is possible to manage all these operations with a single 3D model.

In fact, all the information related to the installations is added to the architectural BIM model: generator, distribution network, terminals, management, control systems, etc. The objects included in the BIM model are intelligent parametric objects that contain all the information that can be used during the design, construction and maintenance of the asset.

This means that any 3D object included in the project contains not only geometric and dimensional information but also performance information, data relating to its supplier, technical data sheets, installation methods, maintenance schedules, etc.

These objects are usually inserted using libraries integrated in the BIM MEP software. It is also possible to customise these catalogues by modifying existing elements or by externally importing them.

Parametric MEP object configurator (ACCA software)

At present, BIM MEP design software also allows the sizing and calculation of installation systems through the application of formulas that respect the parameters envisaged by specific standards.

Furthermore, working on a complete BIM model, you can automatically obtain a cost estimation of the intervention, by simply combining prices selected from the price list with the objects and quantities already represented in the 3D model.

At each stage of the design process, it is easy to immediately highlight any interference issues between architectural, structural and MEP elements and to prevent design errors.

BIM MEP modeling

BIM MEP design starts with the creation of the 3D model of the building. The BIM-based approach during MEP coordination facilitates collaboration among all the different discipline specialists (includes Mechanical, Electrical, Plumbing, Structural engineers), so that they could share comparative data and necessary interdisciplinary information with each other. In order to work in a BIM-MEP perspective, the 3D model must be complete with all the data and information relating to the architectural, plant and structural elements of the project.

For example, a BIM MEP model for a thermal system contains all the data relating to: heating station, piping and distribution system, system management and control, DWV -Drainage, Waste and Ventilation,etc.

When all disciplines are integrated into a single model, the team can achieve a degree of detail that improves design results, reduces risks, contingencies and errors, and accurately assesses the feasibility of the intervention, quantities, timing and sequencing of construction.

The BIM MEP model can also be exported in IFC format to ensure an interoperable, recognised, interdisciplinary language shared by all the professionals involved. The IFC format is precisely that recognised, universal and interdisciplinary language.

The IFC is an open data format not controlled by a single operator, which allows the interchange of an information model without loss or distortion of data or information.

In conclusion, the objective of BIM MEP modelling is to:

• highlight the impact of different design choices
• develop an overall view of the building-plant system
• minimise errors, unforeseen events and cost increases during the construction phase
• avoid interferences between the plant systems and architectural and structural elements that compromise the functionality or the aesthetics of the project
• accurately analyse the costs and timescales of the project.

BIM MEP Practical Case: how to integrate modeling, sizing, and documents into a single workflow

One of the main difficulties in system design is keeping the model, calculations, and documents aligned throughout all phases of the project. Let’s see how to develop a system project with Edificius MEP, to understand how BIM modeling, sizing, and documents can be managed in a single workflow. This practical case shows how, in an environment that integrates modeling and sizing, it is possible to obtain not only the system calculation but also all the necessary project documents.

Modeling a fire protection system

The process starts from an architectural model onto which the elements of the fire protection system are inserted using the BIM object library. The modeling is made particularly simple thanks to tools designed to facilitate the technician’s work: pipes are traced with special drawing functions, while components such as pressurization groups, tanks, valves, and terminals (such as hoses) are selected from the library and inserted into the model. The automatic orientation of some elements and the drawing support tools also allow for quick realization of even more complex connections and supply lines.

For more complex configurations, such as sprinkler networks, a dedicated entity is available that further simplifies modeling. It is indeed sufficient to define some parameters, such as the collector, number of branches, dispensers, and network geometry, so that the system automatically generates the structure, which can then be modified according to project needs.

However, the drawing of the elements is not enough to complete the model: to truly speak of BIM modeling, it is necessary to associate data and technical characteristics with each element, such as design rules and information related to favored and disadvantaged areas. In this case as well, the process is simplified, as much information is already available, and the technician only needs to integrate the necessary data. The association of rules to individual elements and networks occurs through graphic selection functions and indications that guide the user through the various operations.

Before starting sizing, an automatic check verifies the consistency of the model and signals any inconsistencies, such as unconnected pipe sections, allowing for corrections before proceeding with the calculation.

3D model of a fire protection system created with Edificius-MEP

A model that updates along with the project

Once the verification is completed, the model is processed by the calculation engine, which performs the sizing of the system and automatically updates the BIM model with the results obtained. It is precisely in this step that the value of the integration between modeling and calculation becomes concrete: once the model is sent to the sizing engine, the traced elements are verified and, if necessary, automatically resized. For instance, the diameter of a valve can be modified and the branches, initially drawn with a constant diameter, are differentiated based on the number of terminals actually supplied by each section. It is also possible to graphically verify whether the characteristic curve of the chosen pressurization group is compatible with the demand curves of the system.

Once the system is sized, it is possible to produce the design documents: executive projects, technical reports, spreadsheets, and summary sheets, as well as tables with automatic labeling of elements, customizable legends (also with columns dedicated to specific technical data), and summaries with grouping and counting functions.

An important aspect concerns the updating of changes: even moving an already sized element (such as a sprinkler) by just a few centimeters, the system indicates that the model needs to be updated. Once the update is confirmed, all the already created design documents are automatically recalculated.

Executive table of a fire protection system created with Edificius-MEP

Same approach applied to the electrical system

The same approach is applicable to the design of the electrical system. After inserting transformers, switchboards, junction boxes, socket outlets, conduits, and piping, it is possible to configure the components of electrical panels, such as thermal-magnetic circuit breakers and residual current devices, through a specific editing function. The sizing, in this case, concerns, for example, the protections, the overheating in the panels, the balancing of the phases, and the voltage drops. A technical report is also automatically generated for the electrical system, which provides a detailed analysis of each protection, panel, and circuit, along with the calculated electrical quantities. It is also possible to automatically generate various executive drawings, such as floor plans, layouts, and sections, tools that allow for immediate creation and complete the technical documentation of the project.

This approach allows for maintaining consistency among the BIM model, calculation results, and design documents even when the project undergoes changes, limiting manual updates. Those who face this problem daily across multiple systems can find in a BIM software for MEP systems a tool specifically designed to support this activity, allowing to manage modeling, sizing, and technical documentation within a single working environment.

BIM MEP design: advantages

The main advantages of integrated BIM MEP design are:

• 3D design
• integrated and interdisciplinary design that allows collaboration and data sharing between the professionals involved
• control of interferences between the installation system, the architectural and structural models
• speed of project processing
• easy project editing
• automatic production of drawings such as tables, 2D/3D details, plant layouts, BoQ, calculation reports, etc., always connected to the model and updated in real time
• greater accuracy in evaluations
• less chance of error and issues on site
• control over construction time and costs
• greater clarity in communicating project choices
• easy management even during the maintenance phase.

MEP software download

If you are looking for a software or an application to manage all the phases of MEP design, here are some suggestions.

Without any doubt, an effective MEP software must have the following features:

• creating 3D models to get a realistic idea of how the plant system will be developed
• integrating and dynamically manage 3D (geometry), 4D (time) and 5D (costs) models to avoid errors and to obtain the relating project documents (drawing models, BoQ and cost estimates, work schedules, etc.)
• combining in a single 3D model the information regarding the architectural, plant and structural design to check for possible interferences and incompatibilities between the various projects
• viewing the 3D model with Virtual Reality to analyse the project details in an extremely realistic way, as if the plant had already been built.

BIM-MEP software features

If you need to model your installation systems directly in BIM and make the most of the features above listed, we recommend you to use Edificius-MEP.