Architect based in Istanbul with professional experience in architectural design, construction site coordination and project management. I have an academic background in sustainable building design and life cycle assessment (LCA).
I have been working across design office and construction sites, developing my interdisciplinary skills. My work focuses on vernacular and human-centered design. I try to explore the relationship between everyday life and spatial context.
Life Cycle Assessment of Carbon Fiber Reinforced Polymers Used as Reinforcing in Concrete in Comparison with Steel Reinforcing Bars
Yıldız Technical University · Architecture·2025·Supervisor: Prof. Dr. Gökçe Tuna
10B
tonnes
of construction waste produced every year. The building industry accounts for 32–60% of global raw-material extraction.
This is where the research begins. Not with material innovation — but with the scale of the problem it is meant to address.
01 — The Problem
A material with nowhere to go
Carbon Fibre Reinforced Polymers — CFRP — are increasingly used in construction for their extraordinary strength-to-weight ratio. Aerospace, automotive, civil infrastructure: the demand is rising fast. But there is a problem accumulating quietly alongside that growth.
CFRP cannot be recycled the way steel or concrete can. When it reaches end-of-life, it is typically either landfilled or incinerated — both routes releasing toxic gases, polluting soil and groundwater, or both. Several European countries have already banned landfill disposal of CFRP. The waste is piling up faster than the recycling technology can handle it.
The question I started with as an architect was simple: if this material is being brought into buildings, what happens to it when those buildings end?
02 — Global Research Landscape
The world is paying attention
Between 2015 and 2024, research publications on CFRP in construction grew sharply. The map below shows countries with active research programmes. Hover to see publication counts.
Publications on CFRP in construction — Scopus, 2015–2024
03 — Master Thesis · Yıldız Technical University · 2025
Life Cycle Assessment of CFRP used as reinforcement in concrete
SupervisorProf. Dr. Gökçe Tuna
DepartmentArchitecture · Structures Programme
MethodLCA · ISO 14040 / 14044
IndicatorsGWP · AP · ADPf
Most comparisons between CFRP and conventional steel are made by weight: one kilogram of CFRP versus one kilogram of steel. By that measure, CFRP loses — it produces roughly 10 times more CO₂ per kilogram during production. But that comparison contains a fundamental error. It ignores the reason CFRP exists.
CFRP is not used because it is cheap or abundant. It is used because a small amount of it can do the structural work of a much larger amount of steel. The correct question is not "which material is greener per kilogram?" — it is "which material causes less environmental damage when used to do the same structural job?"
That reframing changes everything.
04 — The Experiment
One beam. Two materials. Same strength.
I designed a hypothetical reinforced concrete beam: 6 metres long, 30 × 50 cm cross-section. Both versions carry identical loads — 330 kN·m nominal moment. The only variable is the reinforcement material.
STEEL REBAR
420 MPa · S420
93.41 kg
required
VS
8.2× more mass
CFRP REBAR
850 MPa · with safety factor
11.38 kg
required
Both beams carry the same load — 330 kN·m. The difference is mass: steel needs 8.2× more material to achieve equivalent tensile strength. Each icon above represents one rebar. This ratio is what flips the environmental comparison.
05 — The Result
The comparison that flips
Three environmental indicators were measured across three criteria: Global Warming Potential (GWP), Acidification Potential (AP), and Fossil Resource Depletion (ADPf). The charts below show why the choice of comparison unit determines the conclusion (Stoiber, N., vd.).
Per kilogram — the wrong question
When you compare 1 kg of each material, CFRP appears far more damaging.
Per MPa — the right question
When you compare equal structural capacity, the picture reverses.
−60%
GWP reduction when switching from steel to CFRP bar (per MPa basis)
−50%
Fossil resource depletion advantage of CFRP bar over steel (per MPa basis)
+50%
AP remains higher for CFRP even per MPa — the one category where steel still wins
Environmental impact for the hypothetical beam
600 cm × 30×50 cm beam · same tensile capacity · normalised, steel = 1
One factor that does not appear in the production-phase numbers above is durability in use. Unlike steel, CFRP does not corrode — it maintains its structural integrity in humid, coastal, and chemically aggressive environments where steel reinforcement typically requires maintenance or replacement over time. A building that needs fewer repairs, and can remain in use longer before requiring demolition and replacement, carries a substantially lower environmental burden over its full lifetime. In this sense, the long-term environmental case for CFRP in construction is stronger than the production figures alone suggest.
The research presented here is grounded in tensile strength — the property that makes CFRP most competitive. Compression strength remains a current limitation: CFRP performs less well under compressive loads, which means it is best suited to structural elements that work primarily in tension — beams, slabs, and tensile reinforcement — rather than columns or compression-dominant members. The material's application should follow its mechanical logic.
The thesis also modelled a future scenario: if CFRP is produced from bio-based precursors such as lignin rather than PAN (a fossil-fuel derivative), the environmental performance improves substantially across all categories. The material's current weak point is its manufacturing process — not the material itself.
CFRP, already valued for its mechanical advantages, is a promising low-impact alternative for sustainable construction — provided the comparison is made on structural terms.
— Onur Yıldız, Master Thesis, YTÜ 2025
Studio Projects · 2018–2023
These projects mark the years of rigorous inquiry, studio critique, and first encounters with structure, site, and programme.
Istanbul is not a backdrop. It is a teacher. Every threshold, every alley, every wall that has been repaired a dozen times and remembers each repair — this city has shaped the way I think about space more than any building I have studied. These are five places I return to.
01
Bomonti
View
Click to explore
In the middle of one of Istanbul's densest neighbourhoods, Bomontiada and the Feriköy flea market show how a single open courtyard or an unhurried market can become the most animated point in an otherwise tightly packed urban fabric — drawing people precisely because the city briefly opens up around them.
View
View
"A second thought or a short quote about this place."
02
Balat
Balat's streets were never planned — they accumulated over centuries, curving and narrowing in ways that no grid could produce. That unplanned quality is precisely what makes the neighbourhood feel inhabited rather than organised: the street becomes an extension of the home, where daily life spills out onto doorsteps and cobblestones shared by people of different cultures who have been neighbours here for generations.
View
Click to explore
View
The scale forces a slowness that wider streets cannot. The Ecumenical Patriarchate sitting at its heart is perhaps the clearest sign of how many histories this small neighbourhood still holds.
View
03
Çukurcuma
View
View
Çukurcuma sits close enough to the centre of Istanbul to feel connected, but its narrow streets and frequent dead-ends create a pace that belongs to a different era entirely. Antique shops spill onto the pavement, facades carry the ornament of another century, and the absence of through traffic turns every blocked alley into a niche that the neighbourhood quietly claims as its own.
Click to explore
It is one of those rare places where locals and expats occupy the same streets and both feel equally at home.
View
04
Moda
Moda is a Kadıköy district where streets spill downhill toward the Marmara, framing the water at the end of every slope as though the city were constantly reminding you of its geography. The old tram lines still cut through the cobblestones, and the buildings lining these streets have watched Istanbul from the Asian shore for well over a century. Plane trees arch over the pavements, small parks give the area a human scale that feels increasingly rare in this city.
View
View
Click to explore
View
In recent years, boutique bars, small theatre stages and comedy clubs have settled into its ground floors — keeping the streets animated long past sunset.
05
Eminonu
View
Click to explore
Eminönü still carries the marks of the Ottoman empire in its bones — entrances to ancient inns open onto courtyard gardens in streets you'd never expect, and buildings from entirely different centuries meet at the same crossroads without apology. The chaotic collision between bulky old apartments, loud bargainings in front of the shops and the constant human rush might sound unaesthetic, but it is precisely this clash that gives the place its spirit.
View
Nostalgia arrives uninvited every time.
View
These five places are not destinations. They are a way of seeing.
A library of references — not a list of influences to be cited, but things I return to. Films that taught me about light. Books that changed how I read a room. Buildings I have stood inside and felt something shift.
"Architecture is the will of an epoch translated into space."