Object Integration in BIM Architectural Projects: Doors, Windows, and Openings

One of the key features of BIM software is the ability to create architectural projects using parametric objects such as envelopes, doors, windows, and stairs.

With objects like Door, Window, and Opening, you can enrich your project with elements of any type and shape, composed of detailed components such as jambs, sills, and reveals.

For example, windows can be further customized by adding one or more frames to model elements such as shutters, blinds, or grilles, allowing for a more accurate and flexible representation of architectural components.

Objects can also be imported from the BIM Object Library of Edificius. Using these objects will allow you to achieve a three-dimensional representation of the building model and at the same time an informational system of the construction as a whole and of each of its components.

What differentiates doors and windows as BIM objects from CAD blocks?

While in a CAD software a door or a window is essentially “drawings” made up of lines, arcs, and polylines (often grouped into static blocks), in a BIM environment these elements are intelligent parametric objects.

Here are the three pillars that mark this discontinuity.

Parametricity and Adaptive Geometry

A CAD block is rigid; to change the size of a window, it often needs to be scaled or redrawn, risking deformation of its profiles. A BIM object responds to variables: by modifying the width in the properties panel, the entire object regenerates respecting the established geometric rules, instantly adapting to the thickness of the wall that hosts it.

Informative Content (LoI – Level of Information)

Beyond the aesthetic aspect, the BIM frame carries with it the digital “technical data sheet.” Thermal transmittance (U), acoustic reduction, materials, costs, manufacturer, and maintenance instructions are embedded in the object. This allows for automatic extraction of metric calculations and energy reports without margins of error.

Host-Hosted Relationship (Hosting)

This is perhaps the deepest difference. In a CAD environment, an “opening” is simply an empty space created by removing a section of wall. In BIM, doors and windows “know” they belong to a wall. If you move the frame, the opening moves with it; if you delete the frame, the wall automatically closes. There is a hierarchical and logical relationship that ensures the integrity of the model.

How to choose the correct BIM object from the online catalog

Choosing the right object from an online catalog is not just a matter of aesthetics but of technical and performance coherence. A low-quality BIM object can weigh down the file or, worse, generate calculation errors in the advanced stages of design.

Let’s see what the fundamental criteria are for selecting doors, windows, and openings from digital catalogs without compromising the integrity of your project.

The right balance between LOD and performance

Not always is the most detailed model the best one. It is essential to evaluate the LOD (Level of Development) of the object:

• optimized geometry – avoid objects with an excessive number of polygons or superfluous details (such as invisible screws and fittings) if your goal is a general executive project. An overly heavy model slows down 3D navigation;
• informative coherence – ensure that the object contains the necessary parameters for your design phase (thermal, acoustic properties, and fire resistances).

Format and interoperability

The choice should fall on formats that guarantee communication between different software. Although many catalogs offer proprietary formats, the presence of the IFC standard is the guarantee that the data of your frame will remain readable even if exported or shared with other colleagues (structural engineers, MEP engineers, etc.).

Parametricity and flexibility

A good catalog BIM object must not be a “monolith”. Ensure that it is possible to:

• modify standard dimensions to fit your specific project;
• manage the graphic representation based on the scale (e.g., a greater detail at 1:20 compared to 1:100);
• customize materials and finishes without having to recreate the object from scratch.

How “smart” objects improve the modeling of the building envelope

The evolution of building envelope modeling inevitably involves moving away from static elements in favor of “smart” objects.

In a BIM system, the envelope is not just a simple “box” closure, but a technological organism where doors, windows, and openings dynamically interact with wall stratigraphies.

Below you can better understand how the “intelligence” of smart objects transforms and optimizes the design of the envelope.

Dynamic management of construction nodes

A smart object does not simply “sit” inside a wall but governs its intersections. When we insert a smart window, the software automatically manages the overlap of insulation or the creation of the jamb.

Automation of details: if you modify the thickness of the thermal coat in the envelope, the smart frame adapts the depth of the subframe and the position of the sill without manual intervention.

Continuity of the envelope: smart objects ensure that there are no logical “holes” in the model, guaranteeing that the surface of the frame is correctly subtracted from the wall material calculations.

Real-time energy analysis

The envelope is the main responsible factor for the thermal balance of a building. Smart doors and windows come with transmittance values (U) and solar factor (g). By inserting these objects, the designer can instantly monitor how the variation of a frame influences the overall performance of the facade. There is no longer a need to wait until the end of the project for thermal calculations: the smart object provides the necessary data for preliminary energy checks already in the concept phase.

The “Opening” as an architectural control entity

In the modern envelope, the opening is not synonymous with frame. Niches for installations, technical slots, or simple aesthetic reveals are managed as “empty” smart objects.

Volume subtraction: the opening object communicates to the wall how much material volume to remove, allowing for accurate calculations of cement or bricks.

Registers and legends: each opening is automatically cataloged. This is crucial for site coordination, where contractors need to know the exact number and location of each opening before starting the installation of materials.

Coherence between representation scales

A smart object, if well designed, knows how it should appear. In a 1:100 plan, it will show a simplified geometry; in a 1:20 detail, it will reveal the sections of profiles and seals. This adaptability avoids the proliferation of different files and ensures that the envelope is always correctly represented in every technical document.

How to manage the objects Opening, Door, and Window and define their properties

Below I want to show you a practical example to help you understand how you can operate with BIM architectural design software to perform specific operations with the objects Opening, Door, and Window.

To insert an opening in a wall, we select the “Opening” object and click on the wall at the insertion point. We move the object to the desired position and confirm the position with a new click. We can freely size the opening using the appropriate handles.

Inserting an opening in a wall

Definition of opening properties

We can define the properties of the opening (width, height, jamb, sill, etc.) by specifying its characteristics in the properties box to achieve the desired result.

Customising the properties of openings

Insertion of a BIM object from the Edificius catalog

We can insert a specific door model into our project by selecting it from the BIM Objects Library available in Edificius.
To insert the chosen door, click at the point where you want to place it and then define the characteristics in the properties box to further customize the object to our needs (for example, door dimensions, handle position, frame, etc.).

Positioning a door selected from the catalog

We can insert additional door objects with the same characteristics just specified into the 3D design, thereby further speeding up the creation of new doors.

How to Duplicate and Reuse the Properties of Doors and Windows in BIM

To add more doors to our project with the same characteristics as those just defined, we use the “Pick & Insert” feature, which allows us to copy the properties of an object simply by clicking on it.

The “Pick & Insert” function to copy properties from one object to another

At this point, just click on the desired point to insert the new door with the same characteristics as the previous one.

How to change the alignment of a door

Select a door that has already been inserted; by pressing the “F7” and “F8” keys on the keyboard, we can respectively modify the direction of the door opening and the position of the hinges.

Editing the opening direction and side

Simultaneous Modification of Multiple Doors and Windows

To apply changes to multiple doors, we make a multiple selection (select the relevant doors while holding down the “Shift” key on the keyboard) and proceed with the modifications.

In a single operation, we will achieve the modification of the properties of all selected doors, saving a significant amount of time.

Multiple object selection

Insertion of fixtures

To insert a specific fixture model into the drawing, we can select it from the Edificius catalog and click with the left mouse button at the point in the drawing where we want to insert it.

We type the exact position of the object on the keyboard, press the Enter key to confirm the entered data.

Fixture positioning

Each fixture added can be replaced with additional models simply by modifying the characteristics in the properties box.

After defining the fixture, we can insert a second fixture (for example, the external one) and define all its characteristics.

Typical double external fixture

FAQ on Integrating Objects in a BIM Architectural Project

What differentiates doors and windows as BIM objects from CAD blocks?

While in CAD software a door or a window are essentially ‘drawings’ composed of lines, arcs, and polylines, in a BIM environment these elements are intelligent parametric objects based on three pillars:

1. Parametric and Adaptive Geometry: the object regenerates itself respecting geometric rules and adapting to the wall thickness.
2. Informational Content (LoI): incorporates technical data such as thermal transmittance, materials, and costs.
3. Host-Hosted Relationship (Hosting): doors and windows ‘know’ they belong to a wall, ensuring the integrity of the model if moved or deleted.

How to choose the correct BIM object from the online catalog?

The choice must be based on three key criteria:

1. Balance between LOD and performance: avoid objects with too many polygons that weigh down the file, ensuring they contain the necessary thermal and acoustic properties.
2. Format and interoperability: prefer the IFC standard to ensure readability across different software.
3. Parametric and flexibility: verify that it is possible to modify dimensions, manage the representation according to scale, and customize materials and finishes.

How do ‘smart’ objects improve the modeling of the building envelope?

Smart objects transform the design of the envelope through:

1. Dynamic management of construction nodes: automatically govern intersections, caps, and the edges of insulation.
2. Real-time energy analysis: instantly provide values for transmittance and solar factor.
3. The ‘Opening’ as a control entity: allows for precise calculation of volume subtraction and automatic accounting in schedules.
4. Consistency across scales: adapt geometrical complexity based on the representation scale (e.g., 1:100 vs 1:20).

How to manage the Opening, Door, and Window objects and define their properties?

In a BIM software like Edificius, it is possible to insert an Opening by clicking on the wall and sizing it using handles or the properties box (width, height, threshold). You can insert objects from the BIM Object Library and customize their characteristics (handles, frames, etc.). The software also allows inserting specific models of fixtures (shutters, blinds, grilles) defining their position and technical characteristics in the properties box.

How to duplicate and reuse the properties of doors and windows in BIM?

To speed up modeling, the ‘Pick & Insert’ functionality is used, which allows you to copy all properties of an existing object simply by clicking on it, and then apply them to new entries in the project while retaining the same characteristics.

How to simultaneously modify multiple openings and fixtures?

It is possible to make a multiple selection of the affected objects by holding down the ‘Shift’ key on the keyboard. Once selected, making changes in the properties box will apply them simultaneously to all chosen entities, ensuring significant time savings.