Window is one of the most problematic products for any Developer. Leaving aside the architectural significance, many developers face problems in timely completion of project and delays in getting completion certificate. RERA has also imposed 5 year maintenance responsibility on the developer and norms are getting stricter every year.
Changing needs from construction perspective
The construction industry has seen huge growth in the past few years. This growth may accelerate in the coming years. Every premium project has floor to ceiling windows and the size reaches 6 m in length. The building height has roughly doubled in the last 10 years which has made projects more difficult to manage.
Villa projects & row houses have become very popular after COVID, but here also the window size has increased in height. Facade decoration has become more important and it is necessary to achieve a design match with windows.
Wind load calculations
All developers have to be cautious about wind load safety for windows in high rise buildings. Even glass has to be of adequate thickness.
The calculations are quite simple starting with the wind load specified under Building Standards for the location of building. Based on the height of the window, the deflection of mullion is calculated to confirm that the window selected complies with ASTM standards.
Safety calculation can be asked from the window supplier, who can also submit actual test reports. The calculations are more difficult for complex shape of buildings, where a facade consultant can give assistance.
Past, Present and future of Windows
Many developers in the past have used wood, but it is no longer viable for large projects. Even for villa projects where customers ask for wood, it is difficult to manage the project with carpenters. Faster completion is possible only with factory made products, including kitchen and wardrobe.
Mumbai has been the first city in India to develop high rise buildings starting from 1960’s and has used aluminium windows for a long time. Given the ferocity of monsoon, the step cill has been used extensively to stop water from coming inside. There are many suppliers but the battle with the monsoon is continuing.
UPVC is also popular for new homes and high rises. Many buildings with signature white colour profiles can be seen in all cities. UPVC has its origin in Europe where it is known as a vinyl or energy efficient window. Since weather is cold, the main feature required is the ability to retain heat inside the house. Windows are small and need for ventilation is less.
The new regulations coming in India are making it necessary for developers to use safe and tested windows. This new generation of windows is often known as ‘System Windows’ which is the most common window used in all developed markets.
Also Read: Types Of Aluminium Window – Its Definition Features And Benefits
What is a Systems Window?
There is no commonly accepted engineering definition of a Systems Window. However as the name signifies:
- A System Window design would conform to ASTM, JIS or any of the international standards.
- The important specifications in respect of windows are wind load resistance, water ingress, noise & air penetration, UV resistance etc.
- Test results would be available to confirm compliance to the standard.
- Documented process would exist in respect of materials, manufacturing and fitment at site to assure that the window as manufactured are conforming to standard.
Many manufacturers offer System Windows and the share is constantly increasing in comparison to untested windows offered by extrusion companies. Only cross section or thickness are not indicative of strength as the design of window and hardware is more important.
System Windows and possible last mile gap
System Windows are undoubtedly better, but the last mile quality is in the hands of the window manufacturer. To explain:
Many System Companies work through fabricators who are expected to follow the documented process in respect of materials, manufacturing and fitment at site. There is a scope that may not happen.
Window Companies on the other hand are safer. Manufacturing is done in-house and quality assurance and warranty is in scope of the manufacturer.
Tostem takes this a step further using a pre-engineered design of windows, which is shipped to site in a box and only fixing is done by trained installer. Since 90% quality control is with Tostem, the final quality at site is very good.
Conclusion
The market preference is quickly shifting in favor of System aluminium which is a ‘safe to use’ product in all weather conditions. Architects also prefer aluminium for its fit & finish, safety & ease of use and very less need for service. The design freedom and slim design enhances the aesthetics of the building.
