| Climate and Location | Hot-humid, cold, dry, coastal, high-altitude, or mixed climate. | Define the local climate zone, seasonal temperature range, solar exposure, rainfall, humidity, and wind conditions before selecting the system. | Window performance depends heavily on outdoor temperature, moisture, solar radiation, and exposure conditions. | Project climate data, orientation plan, local building-code requirements, and exposure classification. | High |
| Thermal Insulation | Lower heating and cooling demand while maintaining indoor comfort. | For the complete window, specify a low U-value appropriate to the local code and energy target. Use the whole-window value rather than the frame-only value. | Glass, frame, spacers, seals, and installation all influence real thermal performance. | Whole-window U-value, centre-of-glass U-value, solar heat gain data, and calculation method. | High |
| Solar Heat Control | Reduce overheating in sunny or warm regions without losing useful daylight. | Choose the solar heat gain coefficient according to orientation, shading, latitude, and cooling strategy. Lower values generally reduce solar heat entering the building. | A suitable solar-control strategy can reduce cooling loads and improve occupant comfort. | Solar heat gain coefficient, visible transmittance, shading design, and glazing configuration. | High |
| Daylight and View | Provide natural light and external visibility while controlling glare. | Balance visible transmittance, window-to-wall ratio, room depth, orientation, and external shading. | Higher visible transmittance can improve daylight but may increase glare or solar gain if not managed. | Visible transmittance, daylight simulation, glare assessment, and elevation drawings. | Medium |
| Air Tightness | Limit uncontrolled air leakage and drafts. | Set a maximum air-leakage rate based on the applicable national or regional standard and test the complete operating unit. | Air leakage can increase energy use, reduce comfort, and allow moisture movement through the building envelope. | Laboratory air-infiltration test report, test pressure, product size, and installation-seal details. | High |
| Water Penetration Resistance | Protect interiors from wind-driven rain, especially in coastal or storm-prone locations. | Select a tested water-resistance level suitable for the building height, exposure, façade position, and local rainfall conditions. | Water resistance is affected by drainage paths, seals, joints, installation, and surrounding façade design. | Static or dynamic water test results, pressure level, drainage details, and installation method statement. | High |
| Wind Load and Structural Capacity | Maintain safe operation and limited deflection under local wind pressure. | Calculate design wind pressure from location, building height, terrain, exposure, opening size, and building geometry. | Oversized or high-level windows may require stronger frames, hardware, glass, and fixing systems. | Structural calculations, pressure-test report, maximum tested size, glass thickness, and fixing schedule. | High |
| Acoustic Performance | Reduce traffic, aircraft, industrial, or neighborhood noise. | Define the required indoor noise level and select the complete window assembly based on laboratory sound-insulation results. | Frame joints, trickle vents, perimeter seals, glazing composition, and installation gaps influence sound performance. | Weighted sound-reduction rating, test frequency range, glazing build-up, vents, and perimeter sealing details. | Medium |
| Safety and Security | Prevent accidental falls, forced entry, and unsafe operation. | Use safety glazing where required, restrict openings in vulnerable locations, and specify tested locking and hardware systems. | Safety requirements vary by building use, opening height, occupancy, and local regulations. | Safety-glazing classification, impact-test evidence, opening restrictor details, lock test report, and hardware schedule. | High |
| Fire and Egress | Support emergency escape, rescue access, compartmentation, or fire-rated façade design where applicable. | Confirm opening dimensions, clear opening area, operating force, fire rating, and location-specific egress rules. | A window that meets thermal or security requirements may still fail emergency escape or fire-compartment requirements. | Clear-opening dimensions, operating instructions, fire-resistance test report, and code-compliance statement. | High |
| Material and Corrosion Resistance | Achieve reliable service in humid, polluted, or marine environments. | Specify compatible frame materials, protective finishes, fasteners, drainage, and sealants for the exposure category. | Salt, humidity, pollutants, and incompatible metals can accelerate corrosion and shorten service life. | Finish classification, corrosion-resistance test, material compatibility statement, and maintenance instructions. | High |
| Durability and Service Life | Minimize failures, replacements, and maintenance over the asset life. | Specify tested cycle counts for operation, weather-seal durability, hardware serviceability, and replaceable components. | Initial purchase price does not represent total cost if seals, rollers, locks, or finishes require frequent replacement. | Endurance-test results, warranty terms, spare-parts availability, maintenance intervals, and repair procedures. | High |
| Accessibility and Operation | Enable safe, simple operation for children, older people, and users with limited mobility. | Review handle height, opening force, sill height, clear width, ventilation position, and automation requirements. | Correct operating design improves usability and reduces the risk of misuse or damage. | Operating-force data, handle layout, accessibility details, user instructions, and control-system compatibility. | Medium |
| Ventilation and Indoor Air Quality | Provide controlled fresh-air intake without compromising weather resistance. | Coordinate openable windows, background ventilators, mechanical ventilation, insect screens, and purge-ventilation requirements. | Windows alone may not provide adequate ventilation for every building type or occupancy pattern. | Airflow rate, ventilator acoustic data, filter details, control strategy, and ventilation design drawings. | Medium |
| Sustainability and Embodied Carbon | Meet project environmental targets and reduce life-cycle impacts. | Compare frame material content, recycled content, durability, repairability, transport distance, and end-of-life recyclability. | Long service life and responsible material selection can reduce replacement frequency and environmental impact. | Environmental product declaration where available, recycled-content statement, material declaration, and recycling guidance. | Medium |
| Compliance and Certification | Demonstrate that the selected system meets the destination-market requirements. | Map every required performance value to the applicable local code, recognized test method, and project specification. | Test methods, classification systems, and documentation requirements differ between markets. | Independent test reports, conformity documents, technical datasheets, drawings, and approved installation details. | High |
| Project Size and Customization | Handle standard modules, large openings, unusual shapes, or repeated unit types. | Confirm maximum and minimum tested dimensions, allowable aspect ratios, mullion requirements, corner details, and tolerance limits. | Custom sizes can affect structural performance, production time, packaging, transport, and installation risk. | Shop drawings, production tolerances, maximum unit sizes, sample approval, and interface details. | High |
| Installation and Interface | Integrate the window with insulation, membranes, cladding, sills, flashings, and internal finishes. | Use a coordinated installation detail that provides continuity of air, water, thermal, and vapour-control layers. | Even a high-performing window can fail if the perimeter installation is poorly designed or executed. | Installation manual, perimeter-joint details, tolerances, fixing specifications, sequencing plan, and inspection checklist. | High |
| Logistics and Lead Time | Meet construction milestones across international procurement routes. | Confirm production capacity, approval lead time, packaging, shipping conditions, customs documents, spare-unit strategy, and delivery sequence. | Long-distance supply chains increase the importance of accurate drawings, protective packaging, and replacement planning. | Manufacturing schedule, packing list, shipping dimensions, inspection plan, delivery terms, and contingency plan. | High |
| Budget and Total Cost of Ownership | Balance purchase price with energy, installation, maintenance, replacement, and disposal costs. | Compare complete installed cost and life-cycle cost rather than frame price alone. | Lower upfront cost may lead to higher energy use, repairs, installation complexity, or early replacement. | Itemized quotation, installation cost, maintenance schedule, warranty scope, expected service life, and energy assumptions. | High |
