Summary: Engineer Thomas Chua of TC Structural Designs explains why building safety begins with structural engineering design, early coordination, and proper execution on site. The conversation explores structural integrity, collaboration with architects and contractors, difficult site conditions, earthquake performance, material specifications, building cracks, retrofitting, and how structural engineers help turn design intent into safer buildings in Philippine practice.

Q and A Snapshot

Why are structural engineers important in building safety?
Structural engineers help determine how a building carries loads, responds to movement, and performs during forces such as earthquakes and typhoons. Their work guides the design of foundations, columns, beams, structural frames, and other systems that allow a building to stand safely and perform as intended.

What should architects understand about working with structural engineers?
Architects should involve structural engineers early, especially when a project has bold forms, long cantilevers, planted columns, unusual geometry, or difficult site conditions. Modern software makes ambitious designs easier to study, but collaboration remains essential when the design needs adjustment, compromise, or deeper structural coordination.

What should clients know before building on sloping or difficult sites?
Clients should understand that sloping sites, cliffside lots, and mountain-view properties may require major structural work. Retaining walls, cut-and-fill work, soil protection, and related measures can significantly affect the project budget. Engineer Thomas Chua emphasizes the need to manage expectations early so clients understand the cost and safety implications before construction begins.

How does structural engineering relate to earthquake safety?
Structural engineering helps a building respond properly during seismic movement. Engineer Thomas Chua explains that code compliant design, proper detailing, and correct construction all matter. A major earthquake may still damage a building, but the life safety goal is for the structure to remain standing long enough for people to exit safely.

Does a safe building always remain usable after a major earthquake?
A safe building does not always remain fully usable after a major earthquake. Engineer Thomas Chua explains that the minimum promise of code based design is life safety. The structure should resist collapse during the event, then engineers assess the damage afterward and recommend repairs when needed.

What is ductility, and why does it matter in structural design?
Ductility is the ability of a structure to flex and show signs of stress without sudden collapse. In earthquake and typhoon-resistant design, engineers use proper detailing and the right balance of concrete and steel reinforcement so that a structure can move and crack in controlled ways, giving occupants time to leave safely.

Are all cracks in a building dangerous?
Not all cracks point to structural failure. Some cracks appear in finishes, plaster, or partition walls and may be considered superficial. Other cracks may indicate deeper issues, especially when they appear in beams, columns, or structural members, widen over time, or return after repair. Engineer Thomas Chua stresses that the cause of the crack matters more than the surface appearance alone.

What types of cracks should building owners watch closely?
Building owners should watch for structural cracks such as flexural cracks in beams, shear cracks that often appear diagonally near supports, and spalling where concrete breaks away and exposes or indicates corroding reinforcement. Repeated or widening wall cracks can also signal movement that needs professional assessment.

What happens when construction does not follow the structural plans?
When construction does not follow the structural plans or material specifications, engineers need to test, evaluate, and recalculate the affected parts of the structure. Engineer Thomas Chua gives an example involving an incorrect concrete strength, in which testing and analysis were needed before deciding whether to retrofit, add columns, or revise the architectural plan.

Why is coordination important during construction?
Coordination helps reduce errors between design, engineering, and site execution. Structural plans, architectural intent, contractor decisions, materials, and actual site conditions must align. Chua explains that engineers and architects often act as problem solvers when issues appear on site, but early coordination helps prevent costly corrections later.

When does retrofitting become necessary?

Retrofitting is necessary when an existing structure requires strengthening, repair, or adaptation rather than demolition. This often happens with older homes, sentimental properties, or buildings with structural concerns. Chua notes that retrofitting can be done when the budget allows, but building correctly from the start is usually the better path.

Building Safely Starts with Structural Engineering

Structural engineering carries a significant responsibility in every building project. It rarely becomes the most visible part of a design, yet it shapes how a structure stands, moves, responds, and protects the people who use it.

In this PhilBIG Show conversation, Engineer Thomas Chua of TC Structural Designs joins Architect Chammy Arceo of Fulgar Architects to discuss the discipline behind safer buildings. Their exchange brings together the concerns of architects, clients, contractors, engineers, and project owners who want to understand how structural decisions affect real projects in the Philippines.

The conversation moves from business growth to technical practice, from collaboration to construction site problems, and from earthquake safety to the cracks that clients often notice only after a structure has already been completed.

Building a Firm Around Culture and Responsibility

Engineer Chua’s path into business started early. He shared that entrepreneurship had been present in his family background, with a grandfather who ran a business in Divisoria and exposed him to office work during childhood. That early experience shaped his interest in eventually building something of his own.

He began his career as an employee, then gradually accepted projects on the side. After a year and a half of employment, he saw that his independent work had started taking more of his focus. He decided to pursue it full time, with the mindset that he could always return to employment if the business did not continue.

TC Structural Designs started in 2018 as a solo practice. Before the pandemic, Chua handled the work without employees. During the pandemic, demand for houses grew as people reconsidered the limits of condo living and began looking for homes with gardens, yards, and larger spaces. That shift helped the firm expand. He hired a CAD operator he had previously worked with, then added another engineer. The company eventually grew to a team of nine, including engineers, CAD staff, and administrative support.

For Chua, building a firm required attention to culture. He explained that attitude, willingness to learn, and fit within the company environment became central to hiring. Technical skill mattered, but the company culture needed people who could grow, communicate, and work well with the team.

That same culture shapes how he leads. Structural engineering can be fast-paced and stressful, especially as clients and project teams expect quicker turnarounds due to advances in software and design processes. Chua shared that he tries to reduce unnecessary pressure on his team by keeping communication open and watching over their mental well-being. He wants people to speak up when they feel tired or overwhelmed because fatigue can affect the quality of work.

What Structural Engineers Actually Do

A major part of the conversation clarifies the role of structural engineers. Chua explains that structural engineering is a branch of civil engineering. While many people associate civil engineering with general construction, the field includes several areas such as geotechnical engineering, transportation engineering, and structural engineering.

For TC Structural Designs, the focus is on vertical structures. The firm works on houses, commercial buildings, condominiums, warehouses, and other projects involving columns, beams, foundations, and the structural systems that carry loads. Chua explains that roads and bridges fall outside the firm’s main expertise, since those projects often involve transportation engineering along with structural work.

The conversation also touches on a common misconception in the Philippine context. Chua notes that there is no separate PRC license that specifically identifies someone as a structural engineer. Civil engineers can design, sign, and seal structural plans once they pass the board exam. For those who want to strengthen their structural engineering credentials, membership in the Association of Structural Engineers of the Philippines or graduate studies can help establish specialization.

This point matters because clients often use the term structural engineer without understanding how the profession is formally defined in local practice. It also shows why experience, specialization, professional judgment, and continuing learning become important markers of competence.

When Architecture Meets Structural Engineering

Many architectural projects now explore bold forms, longer cantilevers, planted columns, dramatic spaces, and more expressive structures. Chua connects this shift to advances in design and engineering software.

Architectural software has made complex ideas easier to visualize and revise. Structural engineering software has also advanced, allowing engineers to model ambitious designs, analyze forces, and check whether a system meets code standards. What once required difficult manual computation can now move through modeling, analysis, and verification with greater efficiency.

Chua makes it clear that software does not remove the need for collaboration. When an idea becomes too difficult, inefficient, or structurally demanding, the conversation returns to the architect and engineer. The goal becomes finding a practical middle ground that respects the design intent, satisfies the client, and protects structural performance.

This is where the relationship between architect and structural engineer becomes essential. Good collaboration allows creative ambition to move toward buildable reality. It also gives clients a clearer understanding of what a design requires before construction begins.

Managing Difficult Sites Before They Become Costly Problems

The discussion also addresses challenging sites, especially sloping lots, cliffside properties, and projects with dramatic views. These locations can attract clients because they promise scenery and privacy, but they also introduce structural and cost implications.

Chua explains that the most important step is managing the client’s expectations early. In structural engineering, many problems have possible solutions, but those solutions carry cost, complexity, and construction requirements.

For very sloping terrain, retaining walls, cut and fill work, soil protection, and related structural measures can become extremely expensive. Chua notes that these items can approach the cost of the house itself. Because of this, clients need to understand the implications at the start of development, before the design moves too far ahead.

This lesson matters for both architects and clients. A beautiful site can still demand heavy structural preparation. A responsible project team helps the client see the full picture early, then looks for a solution that fits the requirements, budget, safety goals, and design intent.

Coordination, BIM, and the Speed of Modern Projects

Large projects bring multiple disciplines together. Structural engineers work with architects, mechanical engineers, electrical engineers, electronics engineers, fire protection specialists, contractors, and other consultants. Chua explains that commercial buildings and high rise projects require constant coordination because many systems must fit within the same space.

Tools such as BIM and Revit help project teams identify clashes among architectural, structural, and MEPF elements before they become construction problems. This coordination gives teams a chance to resolve conflicts early.

For smaller houses, coordination can sometimes be less formal because the systems may seem simpler and the project moves quickly. Chua still emphasizes that communication remains important. Some issues are tackled during construction due to speed, but better coordination at the design stage helps reduce avoidable problems.

Construction Reality and the Value of Problem Solving

One of the most practical parts of the discussion centers on what happens when construction does not perfectly match the plans. Chua explains that no plan is completely perfect. Missing details and site discrepancies can appear. When problems arise, engineers and architects must solve them.

He gives an example involving concrete compressive strength. A project required a specific concrete strength for certain columns, but the wrong concrete was ordered and poured into several members. The team then conducted testing, including rebound hammer testing and ultrasonic testing, to understand the actual condition of the concrete and check for issues such as honeycombing. After testing, the engineers ran calculations based on the results and considered possible solutions such as retrofitting, adding columns, or revising the architectural plan.

This example shows why structural safety depends on implementation. A structurally sound design needs proper materials, correct specifications, and disciplined construction. When a site decision fails to follow the plan, the project team must investigate, calculate, and respond with the right remedy.

What Structural Engineers Design for During Earthquakes

Earthquake safety becomes one of the most important topics in the episode. Chua discusses public concern around the West Valley Fault and the possibility of a major earthquake. He explains the difference between magnitude and intensity, a distinction many people confuse. Magnitude refers to the strength of the earthquake source, while intensity relates to how shaking is felt in a specific location.

Chua also explains that structural design follows code requirements. For many seismic sources in the Philippines, engineers consider a range of magnitudes in design. He notes that even if the West Valley Fault is associated with a magnitude of 7.2, the code considers a larger range for design purposes. When the code, the plans, and the construction requirements are followed, the structure should be able to withstand the earthquake force considered in design.

He also clarifies a key point for clients. Earthquake safety does not always mean that a building will remain fully livable after a major event. The life safety goal is that the structure should stay standing during the earthquake, allowing people to exit safely. Afterward, engineers assess the damage and determine the needed repair.

This explanation gives clients a clearer understanding of what structural design promises. It protects life by guiding how a building should behave under extreme force.

Why Buildings Need Ductility

Engineer Chua introduces ductility as an important part of structural safety. During earthquakes and typhoons, structures should be able to flex. A structure that behaves too rigidly can become brittle. Engineers use detailing, concrete, and steel reinforcement in the right balance so that the structure can show signs of distress without sudden collapse.

This is why cracks do not automatically mean immediate failure. In some cases, cracking can show that a structure has absorbed force and developed signs of distress. The important question is what kind of crack appeared, where it appeared, and whether it points to superficial movement or a deeper structural problem.

Understanding Cracks in Buildings

Cracks often alarm homeowners and building owners, so Arceo asks how clients can tell which cracks matter. Chua explains that the first step is to distinguish between superficial cracks and structural cracks.

Superficial cracks often appear in finishes, plaster, or partition walls. Partition walls usually do not carry structural loads. They rest on the structure, and their main effect is their weight. Cracks in these walls do not automatically mean that the main structure is failing. They may appear because of normal movement, settlement, or sway during wind or earthquakes.

Settlement cracks are also common in the first year after a building is completed, as the soil supporting the structure adjusts. If the project has proper soil testing and the settlement stays within allowable limits, these cracks may remain manageable. Contractors often observe them for a period, then repair them once movement stabilizes.

Structural cracks require closer attention. Chua identifies flexural cracks, shear cracks, and spalling as examples that clients should take seriously. Flexural cracks may appear when a beam bends and lacks sufficient strength, size, or reinforcement. Shear cracks often appear at an angle, commonly around 45 degrees near beam supports. Spalling can appear in older buildings when concrete breaks off and reinforcement begins to corrode inside the member.

He also notes that wall cracks can serve as clues when they keep recurring, widen over time, or appear alongside other signs of movement. In those cases, engineers need to investigate the cause rather than simply patch the surface.

Repair, Retrofitting, and the Cost of Late Fixes

When a crack appears, Chua explains that engineers first identify the cause. Sometimes they observe the crack for a month or two to see whether it grows. If the crack stops moving and the structure shows no signs of structural failure, repairs may be straightforward. If the cause is structural, the issue requires deeper investigation, testing, and a proper repair strategy.

Chua also points out that many structural issues can be fixed if the client has the budget. Retrofitting becomes common when owners want to preserve an old house because of sentimental value or heritage. Still, he emphasizes that it is better to get the structure right from the beginning. Retrofitting can become expensive, and in some cases, it may cost enough that demolition and rebuilding become the more practical option.

This is one of the strongest lessons of the episode. Safe building practice begins before problems appear. Proper structural planning, correct implementation, quality materials, and coordinated professional work can prevent costly repairs later.

A PhilBIG Moment Built on Growth

Toward the end of the conversation, Engineer Chua reflects on his PhilBIG moment. For him, the idea has evolved over time. At the beginning, it was landing his first large project. Later, it became the ability to hire engineers and grow the company.

He shares that he had no formal training in running a business or managing people, so each milestone matters. The growth of TC Structural Designs gives him moments to celebrate, especially because that progress includes the people who work with him. Appearing on the PhilBIG Show also becomes one of those milestones.

His reflection closes the conversation with a grounded view of professional growth. Structural engineering is a technical discipline, but the practice also depends on leadership, trust, teamwork, and the willingness to carry responsibility for the safety of others.

Building Safely Starts with Better Understanding

The work of structural engineers often stays behind the scenes, yet it affects every building user. Their decisions shape how structures carry loads, respond to earthquakes, coordinate with architecture, and survive the realities of construction.

Engineer Thomas Chua’s conversation with Architect Chammy Arceo offers a practical reminder for the Philippine building industry. Safer buildings come from clear coordination, proper implementation, honest client conversations, and respect for the structural discipline that holds every project together.

For architects, clients, contractors, and project owners, the lesson is direct. Building safely starts with asking the right structural questions early, following the plans carefully, and treating structural integrity as a central part of responsible building practice.