If SOLID Were Followed Properly, Engineering Codes Would Stop Looking Like Document Bundles and Start Behaving Like Platforms
Most engineering professionals do not wake up in the morning thinking about software architecture.
They think about loads, drawings, deadlines, approvals, safety, cost, site realities, and the uncomfortable fact that a single misinterpretation in a code clause can travel all the way from a PDF to a poured foundation.
And yet, many of the frustrations we experience with modern technical standards are exactly the frustrations that software engineers experience with badly organized systems.
Too much in one place. Too many hidden dependencies. Too many exceptions buried inside general rules. Too many sections that seem to answer three different questions at once. Too many revisions that feel like a full-system shock rather than a controlled update.
That is why I increasingly believe this:
A mature engineering code should not be structured merely as a stack of document types. It should be structured as a platform with layers.
This is where the SOLID principle becomes unexpectedly powerful.
Not because civil engineers need to become software developers, but because SOLID gives us a very sharp language for asking whether a document system is well-designed, maintainable, and safe to evolve.
And that question matters right now.
India’s recent experience with seismic-code revision shows that code reform is not only about better science. It is also about document architecture, implementation readiness, update strategy, and institutional trust. Public reporting says the 2025 revision of IS 1893 was withdrawn in March 2026, effectively restoring the 2016 version, after concerns about consultation and the impact on ongoing projects and costs.
That episode should teach us something deeper than “the revision was controversial.”
It should teach us that how a code is organized is almost as important as what the code says.
What SOLID means, in plain language
For readers from a non-software background, SOLID is a famous set of design principles used to build software systems that are easier to understand, extend, and maintain.
But if we strip away the programming vocabulary, SOLID is really about something much more universal:
How do you divide a complex system so that each part has a clear job, interacts cleanly with the others, and can evolve without breaking the whole?
That is not only a software question. That is also a code-writing question. A standard-writing question. A governance question. A national engineering-capacity question.
Let me translate the five SOLID principles into documentation language.
S — Single Responsibility Principle
Each part of a document system should have one clear job.
A hazard section should define hazard. An analysis section should explain analysis. A site-response section should deal with soil and ground effects. A building-specific section should deal with buildings.
The moment one chapter begins mixing hazard philosophy, soil behavior, analysis exceptions, detailing triggers, and asset-specific provisions in one place, it may still be technically correct, but architecturally it has become heavy.
That is the first smell of a monolith.
O — Open/Closed Principle
A document system should be easy to extend without constantly rewriting the foundation.
If a new seismic technology emerges, or if base isolation needs a revised treatment, or if new nonstructural protection requirements must be added, the standard should be able to absorb that by adding or refining a module.
It should not require rethreading the whole code family each time.
L — Liskov Substitution Principle
A specialized section should behave like a valid specialization of a general section, not like a contradictory parallel universe.
If the general provisions define seismic demand logic, then the building chapter should refine that logic for buildings. It should not silently redefine the same concepts in a way that forces designers to choose which truth they prefer.
In documentation terms, specialization should mean inheritance with discipline, not duplication with drift.
I — Interface Segregation Principle
A user should not be forced to read large amounts of irrelevant material just to perform one legitimate task.
A bridge engineer should not be burdened by building-specific clutter. A building designer should not have to mentally filter tank logic. An AEU specialist should not have to excavate nonstructural rules from deep inside structural chapters.
A good standard is not merely complete. It is also well-targeted.
D — Dependency Inversion Principle
Specialized sections should depend on stable abstractions, not on ad hoc local assumptions.
In code language, the stable abstractions are things like:
These should form the stable kernel.
Then building rules, bridge rules, industrial rules, nonstructural rules, and special technology rules should all depend on that kernel.
That is the difference between a platform and a patchwork.
SOLID is not only for software. It is also for documentation
This is the point I most want non-software professionals to notice.
When we say a document is “clear,” we usually mean the sentences are readable.
But clarity has a second layer.
A document may be grammatically clear and still be architecturally messy.
It may have correct equations, correct tables, and correct terminology, yet still be hard to use because its logic is badly distributed.
This is very common in technical standards.
The writing itself may not be the real problem. The allocation of responsibility is.
One clause becomes too important. One annex secretly carries half the system. One table gets overloaded with concepts that should have been separated. One part becomes “general” in name but practically “mixed-use” in content.
That is why I often say:
Taxonomy is not architecture.
Splitting a standard into Parts 1, 2, 3, 4, and 5 does not automatically make it modular. It may simply create multiple files that still behave like one tangled monolith.
A truly modular standard is not defined by how many PDFs it has. It is defined by whether each part has a clean responsibility and a clean dependency relationship with the others.
The seismic-code example makes this concrete
The 2016 version of IS 1893 Part 1 itself states that it contains general provisions on earthquake hazard assessment applicable to buildings and structures covered in later parts. In other words, even the “general” part acts as a shared core for multiple asset types.
Publicly available summaries of the 2025 family showed a move toward a broader multi-part structure, including separate parts for buildings and other structure classes. Public workshop material also emphasized practical interpretation of IS 1893:2025 together with IS 13920:2025, which shows how tightly the ecosystem of hazard, design, and detailing remains coupled in practice.
That is precisely why the SOLID lens is so useful.
It lets us ask:
These are not software questions anymore. These are code-governance questions.
What a SOLID documentation architecture would look like
If SOLID were followed properly, the seismic code family would be split less like a set of “document types” and more like a layered platform.
The first layer would be the kernel.
This kernel would contain only the most stable shared abstractions:
This layer should not contain building-specific exceptions, bridge-specific behavioral quirks, or nonstructural anchorage details. Its job is not to solve every problem. Its job is to establish the common language of the system.
Then would come the site and geotechnical layer.
This is where soil type, site amplification, SSI, liquefaction, and ground behavior belong. Soil is not a building topic. It is a cross-cutting dependency. Treating it as such immediately improves clarity.
After that comes the analysis layer.
Equivalent static, response spectrum, time-history, and any other approved analysis methodologies belong here. This layer should define how demand is generated, not where all those demands are ultimately consumed.
Then comes the behavior layer.
This layer defines response reduction philosophy, ductility classes, irregularity categories, torsional logic, overstrength assumptions, drift-control philosophy, and other common structural-behavior abstractions.
Then the nonstructural and utilities layer.
Architectural elements, services, equipment, piping, façade attachments, and utility systems deserve a proper interface of their own. They should not be treated as an afterthought inside unrelated structural text.
Only after all that should we arrive at the asset modules:
These are not supposed to reinvent the world. They are supposed to consume the shared abstractions above and apply them to their specific domain.
Finally, we can have special technology modules such as:
That is what a real platform looks like.
Not one heroic document that tries to be everything, but a clear dependency chain:
kernel → site → analysis → behavior → nonstructural → asset-specific modules → special technology modules
Why this matters even for people who do not care about software at all
Because this architecture changes the daily life of real engineers.
A young structural designer no longer has to ask, “Where exactly is the real rule hiding?”
A reviewer no longer has to interpret a clause whose meaning depends on remembering text from three distant chapters.
A software vendor no longer has to guess which output assumptions downstream codes expect.
A regulator no longer has to fear that every revision is a total-system event.
And perhaps most importantly, an update to one area does not automatically feel like an earthquake inside the standard itself.
That is the real benefit of good architecture: controlled change.
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A good standard should behave like a well-run organization
Think of a good hospital.
Emergency medicine is not the same department as radiology. Radiology is not the same as procurement. Procurement is not the same as patient records.
Yet they all depend on common hospital-wide rules: identity, safety, escalation, hygiene, accountability.
That is exactly how a standard should work.
Common rules at the core. Specialized departments on top. Clear handoffs between them. Minimal confusion over who owns what.
A bad standard is like a hospital where one office controls billing, triage, X-rays, medicine storage, infection control, and ambulance routing, and then everyone wonders why every process feels slow and brittle.
The hidden value of SOLID is not elegance. It is governance
This is the point engineers often underestimate.
SOLID sounds like a design philosophy, but in practice it is also a governance philosophy.
A code family designed this way becomes easier to:
The BIS standards-formulation framework itself emphasizes structured processes for revision, amendment, review, and withdrawal. That means the institutional machinery already exists for a staged, layered evolution of standards; what is often missing is a document architecture that makes such evolution less disruptive.
So the issue is not whether the country has a process.
The issue is whether the code family has been designed in a way that lets that process operate gracefully.
Documentation should have APIs too
Here is one more software idea that is useful even for non-software readers.
A good system has a clean interface: it tells other systems what it expects as input and what it produces as output.
Technical standards need that too.
A hazard-and-analysis platform should produce a standard package of outputs:
That package should then be consumed by detailing, materials, proof checking, software tools, approval workflows, and project documentation.
Once you see the system this way, a remarkable thing happens.
The standard stops looking like a pile of clauses and starts looking like a living engineering platform.
That is where our codes should be heading.
This is not an argument against tradition
Let me be clear.
I am not arguing that engineering standards should become fashionable software products. I am not arguing for jargon replacing engineering judgment. I am not arguing that a good clause can be replaced by a clever diagram.
I am arguing for something simpler and more conservative:
A safety-critical standard should be organized in a way that reduces ambiguity, isolates responsibilities, reveals dependencies, and allows change without institutional panic.
That is not a Silicon Valley fantasy.
That is ordinary engineering discipline.
The future of documentation is layered
In the coming years, standards will increasingly interact with:
The old style of writing codes as large narrative masses will become progressively more expensive.
Not because the clauses are wrong, but because the ecosystem around them is changing.
A code that is hard to digitize, hard to parse, hard to isolate, and hard to version will slowly become a governance bottleneck.
That is why the SOLID lens matters so much.
It gives us a way to ask not only, “Is the rule correct?” but also, “Is the document system fit for the next generation of engineering practice?”
That is the larger question.
My closing thought
If SOLID were followed properly, our codes would be split less like a shelf of separate booklets and more like a platform with layers, where each part has one responsibility, every specialist reads the interface that matters to them, and updates can occur without shaking the whole ecosystem.
In that world, the standard is no longer a maze.
It becomes an engineered system in its own right.
And perhaps that is the deeper lesson for all of us:
Technical standards should not merely contain engineering. They should themselves be engineered.
Appendix A: SOLID-style IS 1893:2025
As a SOLID-style code family, IS 1893:2025 should be organized by responsibility layers, not mainly by structure type. Publicly available copies of the 2025 family show that it was already moving toward a broader multi-part structure —
— with more parts under preparation — but that split is still mostly taxonomic. Part 5 also still pulls major topics like geotechnical aspects and architectural elements/utilities back from Part 1, which means the architecture is improved but not yet fully SOLID in the documentation sense. Also, as of March 2026, BIS withdrew the 2025 seismic code and IS 1893:2016 is back in effect, so what follows is best read as an ideal organization model for the 2025 framework rather than the currently operative legal arrangement.
Here is how I would organize IS 1893:2025 under SOLID.
A.1. Part 0 — Compliance and Use Profiles
This would be the front door of the code family. Its purpose would not be to define hazard or analysis, but to tell each user exactly which parts apply to a given project class. For example: ordinary RC building, steel industrial structure, bridge, base-isolated essential facility, or long-distance pipeline. This is the documentation equivalent of a façade: a simple compliance pathway over a more modular internal architecture. BIS’s own standards-formulation manual already supports structured publication, revision, amendment, concurrent running, and withdrawal, so a front-end compliance layer is institutionally compatible with how standards are managed.
A.2. Part 1 — Hazard Kernel
Under Single Responsibility, Part 1 should do only one job: define the common seismic kernel. That means:
This part should not contain building-specific, bridge-specific, or pipeline-specific exceptions. The public 2025 title itself already points in this direction by renaming Part 1 as “Design Earthquake Hazard and Criteria for Earthquake-Resistant Design of Structures — Part 1 General Provisions.” That title is actually a strong clue that Part 1 should behave like a kernel.
A.3. Part 2 — Site Response, SSI, and Geotechnical Seismic Criteria
In a strict SOLID split, soil and site effects should be isolated into their own module rather than being repeatedly referenced across asset chapters. This part would contain:
This is where the current public 2025 structure still looks non-SOLID: Part 5 explicitly sends geotechnical aspects and liquefaction back to Part 1, meaning the soil logic is not yet treated as its own clean responsibility layer.
A.4. Part 3 — Analysis Methods
Analysis should be a separate shared service layer. This part would contain:
That is Interface Segregation in action: the code should let every asset module call the same analysis engine rather than restating analysis philosophy again and again. Publicly, the 2025 split still keeps most of this burden concentrated in the general provisions and then makes building clauses refer back to it, which is cleaner than 2016 but not yet the ideal layered form.
A.5. Part 4 — Structural Behaviour and Performance Rules
This part should define once, for all structure classes:
Again, the public 2025 Part 5 shows that some of this is still bundled inside the building document itself, including revised force-reduction terminology, importance factors, and torsion improvements. Under SOLID, these would ideally be promoted upward into a shared behaviour layer so that buildings, industrial structures, bridges, and other assets inherit from the same abstractions.
A.6. Part 5 — Architectural Elements, Utilities, and Other Nonstructural Systems
AEUs are important enough that they should not live as a borrowed subsection inside the general provisions. A dedicated nonstructural module would contain:
The public 2025 documents show AEUs explicitly present, but Part 5 Buildings still points back to Part 1 for the AEU framework. Under a stricter SOLID split, AEUs would become their own interface module, because they cross structural, architectural, and MEP boundaries.
A.7. Parts 6 onward — Asset-Specific Modules
Only after the shared layers above are defined should the code branch into asset-specific implementations:
This still uses asset-wise parts, but now they become specializations, not containers for everything. That is the documentation equivalent of Liskov Substitution: each asset part should refine the general kernel without silently reinventing it. The public 2025 structure already listed many of these asset-type parts, including future ones under preparation, so the raw scaffold is there. What is missing is the stronger separation between shared layers and asset implementations.
A.8. Special Technology Modules
A SOLID framework would separate technology extensions from asset classes. So instead of burying base isolation only as a special building subtype, I would create explicit extension modules for:
This is the Open/Closed Principle: the code family should be open to extension by adding a module, but closed against repeated surgery on the core hazard and analysis kernel every time a new protection technology matures. The public 2025 family already includes Part 6 Base-isolated buildings, so this tendency exists; the SOLID improvement would be to make such modules more reusable across asset classes where possible.
A.9. Standardized Seismic Output Package
This is not necessarily a numbered BIS part, but it should exist as a formal annex, companion standard, or digital schema. All analysis routes should produce a common output package with:
That lets downstream consumers — RC detailing, steel design, nonstructural checks, software tools, proof-checkers, and approval authorities — all speak the same language. This is the documentation form of Dependency Inversion: downstream specialized codes depend on a stable abstract demand interface, not on ad hoc interpretation of scattered clauses. BIS’s standards manual explicitly emphasizes consistency in terminology, structure, cross-references, gazetting, amendments, and concurrent running, which supports this kind of formal interface thinking.
So, in one clean SOLID map
If I had to rewrite the family in one line, I would organize it as:
Companion annex/schema for standardized seismic outputs
That is more SOLID than a split that starts mainly with “buildings, bridges, tanks, industrial structures.”
The short verdict
So, as per SOLID, IS 1893:2025 should be organized less like a shelf of separate structural-type documents and more like a layered platform: first define the shared abstractions once, then let each asset-specific part consume them. The published 2025 family had already moved in that direction by separating general provisions from buildings and other structure types, but because Part 5 still imports major topics like geotechnics and AEUs back from Part 1, it remained only partially modular, not yet fully SOLID.
