When a government department, financial institution, hospitality group, or large corporate organization issues an RFP for switchable glass, the specification can look straightforward.
Switchable Glass. Transparent when powered. Opaque when switched off.
But that is not a specification. It is a product category, and in high-stakes projects, the difference matters.
A loosely written RFP can leave enough room for multiple interpretations, allowing products with very different materials, optical performance, electrical systems, manufacturing standards, and expected lifespans to compete on the same tender.
The result? A project may appear to save money at procurement stage, only to pay considerably more through premature replacement, maintenance, performance complaints, electrical issues, or remedial work later.
For architects, consultants, project management consultants, and procurement teams, the better approach is simple: specify measurable performance and engineered system requirements, not just the name of the product.
Here are three commonly overlooked loopholes that deserve attention in your next switchable glass RFP.
Loophole 1: Vague Interlayer Requirements
The Problem: "Any Suitable Interlayer"
One of the most important components in laminated smart glass is also one that can easily disappear into a generic tender specification: the interlayer.
An RFP that simply permits "PVB or equivalent" without defining the required material performance can create a significant quality gap between competing products.
Why Does This Matter?
Buildings operate in real environments. Humidity, temperature fluctuations, UV exposure, and long-term environmental stress can all affect laminated glass assemblies. An interlayer that does not provide the required resistance to moisture can contribute to issues such as edge yellowing, clouding, and delamination over time.
For a prestigious hotel, a financial institution, or a government facility, replacing large areas of installed glazing because of premature deterioration is far more disruptive than selecting the correct specification at the outset.
The Specification Fix
For demanding architectural applications, the RFP should clearly define the required interlayer technology rather than leaving the choice completely open.
Privetek recommends specifying thermosetting EVA (Ethylene Vinyl Acetate) manufactured using certified German lamination protocols, including the Evguard standard, with a high degree of cross-linking.
The objective is not simply to specify a particular material name. The objective is to establish a laminated glass construction designed for long-term performance and improved resistance to moisture-related deterioration, particularly in demanding or humid environments.
A good RFP should therefore define:
- Interlayer material and construction
- Required moisture resistance
- Applicable manufacturing and lamination standards
- Required cross-linking/performance characteristics
- Long-term durability expectations for the intended environment
The lesson for specifiers is straightforward: if the interlayer is left vague, the tender may compare products that are not genuinely equivalent.
Loophole 2: "Transparent When Powered" Without Optical Benchmarks
The Problem: A Subjective Definition of Clarity
"Transparent when powered" sounds reasonable.
But what does transparent actually mean?
Without measurable optical criteria, one supplier's "clear" glass can look very different from another supplier's.
This becomes particularly important in spaces where visual quality matters: boardrooms, executive offices, trading floors, hospitality suites, healthcare environments, observation areas, and premium architectural interiors.
A panel may technically switch from opaque to transparent while still exhibiting excessive haze, reduced clarity, or an undesirable milky appearance.
And the problem becomes even more noticeable when glass is viewed from an angle.
The Specification Fix
Optical performance should be expressed through measurable requirements rather than subjective descriptions.
For example, an RFP can establish benchmarks such as:
- Visible Light Transmission (VLT): >85% in clear mode
- Haze factor: <3%
- Clear mode should maintain a clean, transparent appearance without visible milky undertones
- Performance should be evaluated across relevant viewing angles, not only from a straight-on position
These requirements give consultants and procurement teams something objective to compare.
They also make it harder for a product with noticeably inferior optical performance to qualify simply because it technically satisfies the phrase "switchable glass."
Why This Matters on a Major Project
Imagine specifying premium switchable glass throughout a corporate headquarters and discovering after installation that different areas have noticeably different levels of clarity.
The product may technically function. But function alone isn't enough. In high-end architecture, optical consistency is part of the finished building's quality.
A strong specification therefore asks not only:
Does the glass switch?
It asks:
How clear is it when switched, how much haze does it have, and how does it perform when viewed from different angles?
Loophole 3: No Defined Electrical Safety or System Requirements
The Problem: Treating Switchable Glass as Ordinary Glass
Switchable glass is not simply a pane of glass. It is an electrically controlled architectural system.
That means the glass itself is only part of the specification. Transformers, power distribution, busbars, controllers, wiring, protection systems, and installation methodology can all influence the performance and reliability of the completed installation.
When an RFP leaves these requirements undefined, there is potential for incompatible or low-grade electrical components to enter the supply chain.
That can create issues ranging from micro-flickering and inconsistent switching to power distribution failures and compliance concerns.
On a small installation, this can be inconvenient. On a large project with hundreds or thousands of square meters of switchable glass, it can become a serious operational problem.
The Specification Fix
The electrical architecture should be clearly defined within the tender documentation.
For demanding commercial and institutional applications, the specification should address:
- Commercial-grade low-voltage architecture
- 48V–60V AC operating architecture, as appropriate to the engineered system
- Suitable transformers and power supplies
- Properly engineered busbars and power distribution
- Surge protection
- Internationally recognised electrical safety certifications
- System-level compatibility and testing
- Long-term reliability requirements appropriate to the building's expected lifecycle
The goal is to make sure the electrical system is engineered as part of the switchable glass solution, not treated as an afterthought.
After all, a premium glass product connected to an inadequately specified electrical system is still an inadequately specified installation.
The Bigger Problem: When "Lowest Price" Becomes the Only Comparison
There is a common misconception in procurement that products become comparable simply because they share the same product description.
They don't.
Two suppliers can both offer "switchable glass" while using different:
- Interlayer technologies
- Lamination processes
- Optical specifications
- Electrical components
- Safety certifications
- Quality-control procedures
- Testing protocols
- Long-term performance expectations
If the RFP does not distinguish between these variables, procurement teams can end up comparing different technical solutions as though they were identical products.
That is where the initial price can become misleading. A lower bid may look attractive on paper. But if the system subsequently develops optical defects, requires component replacement, suffers from electrical issues, or needs premature glass replacement, the original saving can disappear quickly.
For high-value projects, total lifecycle risk should be part of the procurement equation.
What Should a Strong Switchable Glass RFP Include?
A well-engineered specification should leave as little ambiguity as possible. At a minimum, consultants and project teams should consider defining:
1. Glass Construction
Specify the required glass build-up, thickness, safety characteristics, and laminated construction.
2. Interlayer Technology
Define the required interlayer material, moisture resistance, lamination process, and applicable standards.
3. Optical Performance
Set measurable requirements for VLT, haze, clarity, and viewing-angle performance.
4. Electrical Architecture
Define operating voltage, transformers, power distribution, busbars, protection, and relevant safety certifications.
5. Testing and Documentation
Require appropriate technical documentation, test reports, certifications, and quality-control evidence rather than relying solely on supplier declarations.
6. Lifecycle Expectations
Consider the intended application, environmental conditions, operating cycles, maintenance requirements, and expected service life.
7. System Integration
Specify how the switchable glass will interface with controls, building systems, and the project's electrical infrastructure.
This transforms the RFP from a generic product request into a performance-led architectural specification.
Specify the Performance. Protect the Project.
The purpose of a good specification isn't to make procurement more complicated. It is to make the procurement process more meaningful.
When a project specification clearly defines the materials, optical benchmarks, electrical architecture, safety requirements, and expected performance, suppliers are required to compete on genuine technical equivalence rather than simply offering the cheapest product that fits a generic description.
That is particularly important for projects where failure is expensive.
Whether the application is a national defence institution, a Tier-1 bank trading floor, a corporate headquarters, or a 5-star hotel, switchable glass should be evaluated as part of the building's long-term infrastructure, not merely as an interior design feature.
At Privetek, our approach is built around this principle. Through engineered switchable glass solutions developed in collaboration with Evguard Germany, we focus on the specifications that matter beyond the initial installation: material quality, optical performance, electrical architecture, safety, and long-term reliability.
Because the smartest procurement decision isn't necessarily the lowest initial quotation. It is the specification that prevents the wrong product from being selected in the first place.
Working on an Upcoming Tender?
If you are an architect, consultant, project management consultant, procurement professional, or developer working on a government, corporate, financial, hospitality, or other high-stakes project, a detailed technical specification can help eliminate ambiguity before the tender is released.
Comment below or contact Privetek to request our Architectural Master Specification Blueprint, designed to help project teams establish clear technical requirements and reduce the risk of sub-standard alternatives entering the tender.
Frequently Asked Questions
1. Why isn't "switchable glass" enough for an RFP?
It only defines the product category. A proper RFP should specify materials, optical performance, electrical requirements, safety standards, and durability.
2. Why does the interlayer matter?
A high-quality interlayer helps protect against moisture-related issues such as yellowing, clouding, and delamination. Thermosetting EVA can provide improved long-term durability in demanding environments.
3. What optical standards should be specified?
Set measurable benchmarks such as VLT above 85% in clear mode and haze below 3%, along with clear viewing performance from relevant angles.
4. Why specify the electrical system?
Smart glass relies on electrical components, not just the glass. Proper transformers, busbars, low-voltage architecture, surge protection, and safety certifications help ensure reliable operation.
5. How can a vague RFP increase project costs?
It can allow lower-grade alternatives to compete on price, potentially leading to premature replacement, maintenance, performance issues, and higher lifecycle costs.
6. What should a switchable glass RFP include?
It should define glass construction, interlayer, optical performance, electrical architecture, certifications, testing, and lifecycle requirements to ensure genuine technical equivalence.
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