India’s public sector construction has undergone a fundamental specification shift. Government buildings, universities, hospitals, metro stations, and institutional campuses built before 2020 were routinely constructed with standard aluminium windows and single-pane or basic double-pane glass. In 2025 and 2026, that default no longer exists — not because the market has voluntarily moved, but because mandatory compliance frameworks now require demonstrably better performance.
The Energy Conservation Building Code (ECBC) 2017, the Bureau of Energy Efficiency (BEE) star rating system for commercial buildings, and the GRIHA certification framework — which the Government of India has made mandatory for all centrally funded buildings above a certain scale — collectively establish fenestration performance standards that standard aluminium windows with clear glass cannot meet. For architects, consultants, and procurement officers working on Delhi NCR government and institutional projects, understanding which window specifications qualify and what documentation is required is not optional. It is the difference between a project that passes its energy compliance review and one that requires redesign.
This guide covers both.
The Regulatory Landscape: What Delhi Government Projects Must Meet
ECBC 2017 and its Composite/Hot-Dry Climate Zone Requirements
Delhi falls under ECBC 2017’s Composite climate zone. The code’s mandatory requirements for commercial buildings (which includes most government and institutional typologies) specify:
- Maximum Window-to-Wall Ratio (WWR): 40% for most building types in the Composite zone
- Maximum SHGC (Solar Heat Gain Coefficient): 0.25 for most orientations with WWR above 20% — a stringent requirement that eliminates standard clear glass from compliance
- Maximum U-value for the overall window assembly (glass + frame): Varies by projection factor, but for unshaded facades typically requires overall window U-value below 3.3 W/m²K — achievable with double glazing but not with single glass
For government buildings pursuing ECBC Enhanced or Super-Efficient targets (required for some central government projects), the requirements are stricter: SHGC below 0.25 and overall window U-value below 1.5–2.0 W/m²K, which requires thermally broken frames and Low-E double glazing at minimum.
GRIHA 5-Star Mandatory for Central Government Buildings
The Government of India circular requiring GRIHA 5-Star certification for all centrally funded government buildings above a threshold scale applies directly to major institutional construction in Delhi NCR — including ministry buildings, CPWD projects, educational institutions under central funding, and public hospitals above specified bed counts. GRIHA Criterion 11 (Energy Performance) scores fenestration SHGC and U-value as part of the mandatory energy compliance package. GRIHA documentation requires certified glass performance data, frame U-value calculations, and a per-orientation SHGC compliance calculation.
BEE Commercial Building Star Rating
For institutional buildings where BEE star rating is being pursued (increasingly common for government buildings seeking to demonstrate sustainability credentials), fenestration performance is included in the energy compliance pathway. Higher star ratings require better window performance specifications.
What Window Systems Actually Comply
The specification that meets all three frameworks for Delhi’s Composite climate zone:
Frame: Thermally broken aluminium — required to achieve overall window U-values below 2.0 W/m²K for enhanced compliance targets. Standard aluminium frames (U-value 5.0–6.0 W/m²K) pull the area-averaged overall window U-value above enhanced compliance thresholds when combined even with quality glass. For any GRIHA target above 3 stars or ECBC Enhanced compliance, thermally broken frames are effectively mandated by the performance calculation.
Glass: Low-E coated double-glazed unit with soft-coat sputtered Low-E on surface 3. Performance targets for Delhi Composite zone:
- SHGC: 0.23–0.28 (meets ECBC mandatory 0.25 maximum for unshaded south and west facades)
- U-value (glazing unit): 1.1–1.4 W/m²K (argon fill recommended for government projects with enhanced performance targets)
- VLT: Minimum 40% for occupied spaces (daylighting credit in GRIHA requires adequate visible light transmittance — over-tinted glass that achieves SHGC compliance at the expense of VLT loses daylighting points)
For east-facing facades: The ECBC M-factor calculation using morning shadow from adjacent buildings and the building’s own projection factor may allow a slightly higher nominal SHGC on east facades. Consult ECBC Table 4.4 for the specific M-factor applicable to your building’s geometry.
For north-facing facades: SHGC requirements are less stringent (direct solar radiation doesn’t fall on north facades in Delhi). The primary performance requirement shifts to U-value for winter heat loss management, and acoustic performance becomes the dominant specification driver for institutions near arterial roads.
The Documentation Package for GRIHA/ECBC Compliance Submission
For Delhi government and institutional projects, the fenestration compliance documentation package typically required for GRIHA or ECBC submission includes:
1. Glass performance certification. Performance data for the specified glass unit — SHGC, U-value, and VLT — tested to EN 673 or NFRC standards and certified by an accredited testing laboratory. This must be from the glass manufacturer and specific to the glass unit being supplied (not a generic specification for the glass type).
2. Frame U-value calculation. Per ISO 10077, the frame U-value must be calculated and documented. For thermally broken aluminium frames, this typically falls in the 1.6–2.2 W/m²K range. For standard aluminium frames, the U-value (5.0–6.0 W/m²K) typically disqualifies the window from enhanced performance compliance.
3. Overall window U-value calculation. The area-weighted average of centre-glass U-value, edge-of-glass U-value, and frame U-value, calculated per ISO 10077. This is the value compared against the ECBC or GRIHA threshold.
4. SHGC compliance calculation per orientation. Using ECBC Table 4.4 M-factor methodology, each facade’s weighted average SHGCeff must be demonstrated to fall within the prescribed maximum. The calculation must be specific to the building’s geometry (window sizes, projection factors from overhangs or adjacent structures).
5. Window schedule. A schedule documenting the glass and frame specification for each window type in the project, cross-referenced to the compliance calculations above.
Thermaline® provides the glass performance data sheets, frame U-value calculations, and overall window U-value documentation in the format required for GRIHA and ECBC submission. For projects requiring M-factor calculations, our technical team works with the project architect or energy consultant on the facade-specific analysis.
Competitor Reality for Government Procurement
Delhi’s government and institutional project market attracts a broad range of window suppliers at the procurement stage. Understanding the competitive landscape helps procurement officers and project architects evaluate claims accurately.
ALCOI is actively marketing itself as India’s leading aluminium window brand for 2026-27 through press releases distributed on wire services, claiming to “set the standard” for the construction landscape. Their product range covers casement, tilt-and-turn, and sliding systems. However, published documentation specifically for GRIHA compliance submissions — SHGC data, frame U-value calculations in ISO 10077 format, ECBC Composite zone compliance calculations — is not prominently accessible in their public materials. For a government project that requires this documentation, verify availability before specifying.
Koemmerling Aluminium Systems (formerly AluPure), recently rebranded in December 2025, brings German engineering backing and genuine thermal performance credentials. Their transition to the Koemmerling brand represents access to over 125 years of German fenestration engineering. However, the rebrand means institutional procurement officers should verify that GRIHA compliance documentation packages are available in their new branding framework and that India-specific ECBC Composite zone calculations (as distinct from European energy code calculations) are offered.
Prominance operates primarily in the uPVC segment and would not typically be the specified material for large-format institutional aluminium curtain wall or window applications.
Thermaline® has direct experience providing the technical documentation required for GRIHA and ECBC compliance submissions on Delhi NCR institutional and government projects. Our EcoCasement® and EcoSlide® systems, together with our commercial fixed-lite configurations, cover the range of fenestration typologies typical in government building projects. We provide:
- Certified glass performance data sheets in submission format
- ISO 10077 frame U-value calculations
- ECBC Composite zone SHGC compliance calculations per orientation
- BEE and GRIHA documentation support throughout the submission process
Procurement Guidance for Government Projects
For procurement officers and project teams handling government building window procurement in Delhi NCR:
Specify performance, not product names. Frame U-value, glass SHGC and VLT, and overall window U-value are the measurable criteria that compliance reviewers check. Specifying these values, rather than brand names, ensures the procurement delivers compliance-ready products and protects against post-award substitution of inferior specifications.
Require compliance documentation as part of the tender submission. Ask tenderers to include glass performance certificates, frame U-value calculations, and SHGC compliance calculations per orientation as mandatory tender submission documents. Suppliers who cannot provide these at tender stage cannot reliably provide them at compliance review stage either.
Factor in installation specification. ECBC and GRIHA compliance reviews can include air infiltration measurements. A compliant window product installed with a non-compliant perimeter seal system (single-bead silicone rather than three-layer sealing) can fail air infiltration requirements even when the window itself would pass. Specify the installation methodology alongside the product.
Thermaline® is available to provide pre-bid technical briefings for Delhi government and institutional project teams — covering compliance requirements, documentation processes, and specification options specific to your project’s GRIHA star target or ECBC compliance level.
FAQs
What regulatory frameworks govern fenestration in Delhi/NCR government projects and what are their key requirements?
The regulatory landscape is defined by ECBC 2017 with Composite climate zone requirements, GRIHA 5-Star mandatory for centrally funded buildings, and the BEE Commercial Building Star Rating. ECBC 2017 sets limits such as a maximum Window-to-Wall Ratio of 40% in the Composite zone, a maximum SHGC of 0.25 for most orientations with WWR above 20%, and an overall window U-value typically below 3.3 W/m²K, with enhanced targets demanding SHGC below 0.25 and U-values between 1.5 and 2.0 W/m²K. GRIHA 5-Star requires certified glass performance data, frame U-value calculations, and per-orientation SHGC compliance as part of its Energy Performance criteria. The BEE star rating pathway includes fenestration performance in the energy compliance, with higher star levels requiring better window performance.
What window system specifications meet the requirements of ECBC, GRIHA, and BEE for Delhi’s Composite climate zone?
The compliant specification uses a thermally broken aluminium frame to achieve overall window U-values below 2.0 W/m²K for enhanced targets. Glass should be Low-E coated double-glazed with soft-coat sputtered Low-E on surface 3, aiming for SHGC in the 0.23–0.28 range, U-values for the glazing unit of 1.1–1.4 W/m²K, and a minimum VLT of 40% for occupied spaces. East facades may allow slightly higher SHGC due to M-factor calculations; north facades focus more on U-value and, for nearby roads, acoustic performance.
What documentation is required for GRIHA/ECBC compliance submission?
The package typically includes: 1) Glass performance certification with SHGC, U-value, and VLT tested to EN 673 or NFRC and certified by an accredited lab; 2) Frame U-value calculation per ISO 10077 for thermally broken frames (1.6–2.2 W/m²K) or 5.0–6.0 W/m²K for standard frames; 3) Overall window U-value calculation per ISO 10077; 4) SHGC compliance calculations per orientation using ECBC Table 4.4 M-factor; 5) Window schedule linking glass and frame specifications to the compliance calculations. Thermaline provides these data sheets and calculations in submission format.
Which competitors are active in Delhi/NCR government procurement and what should buyers verify?
Competitors include ALCOI, Koemmerling Aluminium Systems (formerly AluPure), and Prominance. ALCOI promotes itself as a leading brand but may not publicly provide GRIHA/ECBC submission documentation. Koemmerling has German engineering credentials but buyers should verify availability of GRIHA compliance documentation and India-specific ECBC calculations under the new branding. Prominance focuses on uPVC and is less typical for large-format institutional aluminium systems. Thermaline has direct experience supplying the required documentation for GRIHA and ECBC submissions.
What procurement guidance should government project teams follow for fenestration?
Specify performance metrics rather than product names, including frame U-value, glass SHGC and VLT, and overall window U-value. Require compliance documentation as part of the tender submission, such as glass performance certificates, frame U-value calculations, and SHGC calculations per orientation. Include installation methodology in the tender to account for air infiltration requirements, as non-compliant seals can cause failures even if the product meets other specs. Thermaline offers pre-bid briefings to explain compliance requirements and documentation options for GRIHA or ECBC targets.
