How green buildings benefit owners and occupants
Amit Khanna, design principal, AKDA, explores if office buildings should go ‘all glass’ when sustainable buildings are the need of the hour
Instead of green buildings, I prefer to use the term sustainable buildings. From an owner’s perspective, a sustainable building provides three main benefits. The first is the substantial reduction in energy consumption, since the biggest long term expense to an owner is the energy consumed by the building. Good building envelope design can reduce the amount of energy required to heat/cool the building, as well as reduce the need for artificial lighting during daytime.
The second is the increased likelihood of being able to attract tenants based on a sustainable design. End-users, whether renters or buyers or simply visitors, have a growing appreciation for the value generated by sustainable buildings for the larger environment. The third benefit is the various incentives offered by governmental and independent agencies for those who invest in sustainable buildings. These are offered in the form of tax deductions, lower energy tariffs, or the ability to source raw materials for items like solar panels at subsidised rates.
Occupants are also beneficiaries of sustainably designed buildings in a number of ways. The first benefit is the increased well-being of occupants of buildings designed with natural ventilation and natural materials, reducing “sick building syndrome”. This is due both to the better air quality within the building and the availability of open green spaces incorporated within the building. Secondly, those who use sustainably designed buildings incur the benefits of a naturally lit living and working environment. Additionally, the smart features of such buildings, such as occupancy sensor based interior lighting, motion-based intruder monitoring, automated time-based exterior lighting, etc., offer increased convenience and security to building occupants.
Should office buildings go ‘all glass’?
Well, the simple answer is that they should not!
Glass is an excellent material for exterior cladding, but the appropriate use of glass is mandatory before it can be classified as the right material for office buildings. There are many factors which determine whether or not glass is being used correctly on a building facade.
First, the size of glass should take into account the scale of the building, the overall design and views from inside the building. A balance must be struck between the larger sizes required for view, and the smaller sizes recommended for handling purposes, replacement cost and ease of fixing.
Secondly, the thickness of glass is an important consideration. To merely use 6mm glass for large surfaces is not recommended. The design of the facade must take into account the wind load on the panels and the correct thickness of glass must be chosen.
Thirdly, the choice of insulated, toughened and laminated glass is often seen as a mutually exclusive selection. However, the correct solution often relies on a combination of these for the best result. Insulated glass reduces heat transmission, while toughening and laminating strengthen the glass, while increasing sound insulation. Thus, it may be possible to specify a double insulated glass with one side toughened glass, while the exterior side may be laminated for security.
Also, the orientation of the building determines the choice of whether to select tinted, reflective or clear glass. The colour of the glass, along with the tint/reflective film should be employed based on the movement of the sun and presence of neighbours, etc.
Lastly, the possibility to integrate other materials into the overall building design can help reduce the visual impact of an all glass building. Popular choices include stone and aluminium panels, however solar panels are also becoming popular as a possible material to supplement glass in exterior cladding.