Introduction

When it comes to designing safe and efficient buildings, the structural layout plays a crucial role. At the heart of this layout is the beam-column framework, which forms the backbone of any structure.

Unfortunately, many young engineers often skip a crucial step: they jump straight into software like ETABS without first developing a thoughtful beam layout. But taking the time to plan where your beams go is essential—it affects structural safety, design efficiency, and coordination with architecture and services.

So, how do you determine where your beams should go?

Here are 3 primary reasons why beams are necessary, and how to think about their positioning in any building project.

Why Beams are Essential in a Building

Beams aren’t just structural elements—they serve multiple purposes in any design. Understanding their roles helps civil engineers, architects, and MEP professionals work in sync, avoid redesigns, and speed up construction.

Let’s break it down into three key functions:

1. To Divide Slabs into Manageable Spans

Slabs take the load from usage and distribute it to the beams, then to columns, and finally down to the foundation. The span of the slab determines how thick it should be. For typical buildings, slab thickness between 100 mm to 150 mm is considered ideal.

If a slab spans too far without support, it requires more thickness and reinforcement, which isn’t economical. That’s why beams are introduced to break up large slab spans, keeping them within practical and cost-effective limits.

2. To Support Walls That Don’t Align Vertically

In multi-storey buildings, it's common for wall layouts to vary between floors. Sometimes, a wall on the upper floor doesn’t align directly above a wall or beam below. In such cases, it can sit on the slab—but that slab must now carry the wall’s load, which might not be structurally or economically feasible.

Instead, introducing a beam under such walls is a smarter choice. However, you shouldn’t just place a beam under every wall. You need to balance between slab span control and wall support—something that comes with experience and thoughtful judgment.

3. To Tie Columns Together for Seismic Stability

Tying columns with beams increases a building's lateral resistance—critical in a seismically active country like India. Unconnected columns behave like tall, slender elements prone to swaying. This increases bending moments, reinforcement requirements, and overall cost.

When aesthetics restrict beam placement—such as in open-plan or premium spaces—you can use a concealed beam (same thickness as the slab) to tie columns. But remember: concealed beams aren’t structurally stiff enough to support slabs, so they should only be used for tying, not as slab support.

Other Situations Where Beams May Be Needed

Apart from the three key points, beams may also be added due to:

Renovation Work: When modifying existing buildings (adding stairs, changing usage), new beams may be introduced.


Cut-Outs & Shafts: Large openings for services or ventilation require extra beams for edge support.


Aesthetics: Sometimes, to avoid visible beams or to maintain symmetry, designers may add additional structural members.

Each project has its own unique challenges, and sometimes beam decisions are influenced by on-site conditions or changes in design scope.

How to Get Better at Beam Layout Decisions

Mastering the art of beam positioning comes with practice. Here are a few tips to grow your skills:

1. Study Structural Layouts

Look at as many real-world drawings as you can. Focus on understanding the architectural logic, MEP layout, and how structural members are arranged to support both.

2. Visit Construction Sites

Seeing structures in real life gives you a better perspective than working solely with 2D drawings or software. Don’t hesitate to ask senior engineers questions on-site.

3. Work on Real Projects

Hands-on experience is the best teacher. Try to intern or work with experienced structural consultants where you can participate in actual projects, especially during the layout planning phase.

4. Enroll in Practical Structural Design Courses

Courses that offer real project-based learning with mentorship can significantly enhance your understanding. If you're looking for such programs, check out the ones I offer—they're designed to replicate the experience of working in a structural consultancy.

Summary

Deciding where to place beams and columns is a core competency for structural engineers. A well-planned beam layout not only ensures structural integrity but also improves coordination with architects and services, reducing errors and delays.

So if you're just starting out, don’t rush into software modeling. Instead, spend time understanding structural schemes, learning from site visits, studying drawings, and practicing beam positioning. These foundational skills will help you design better—and build better.