Sunday, February 22, 2009

Why Green Glass?

Over the past 5 years, I have seen many green glass windows and steel being replaced by new aluminum windows with clear glass.

I suppose that many residents feel that the old windows are too old for their own good and surely, new aluminum windows are better right?

Actually, if you think about it, the old windows have survived for 70 years or more, and while some parts are rusty, all they actually needed was a burning off of the many layers of over painting, to be repainted, and then re-oiled.

Have you also noticed how the old windows have window handles that let you not close them completely so that you can still have ventilation - in a secure manner - in the house even when you are not in and want to shut the windows?

That is something that is a design skill by the UK makers - Crittal Windows - which the new windows cannot provide - and honestly, aluminum being a softer metal, it is unlikely that they will last for as long as the steel originals!

Onto the topic of green glass.

Have you noticed that the green glass is used for the outside facing - i.e. East and West facing windows and clear white /frosted glass is used for the airwell windows?

This too is a design consideration.

For the outside windows that face the morning and afternoon sun, before there was air/con, it was important to cut out heat and glare. Thus the green was used as an early example of 'tinted glass' that would achieve the same effect against our harsh tropical sun. If you have been inside an original room with the green glass on a sunny day, you will notice this physical and psychological effect. It is still bright enough if you don't paint your internal walls a dark colour.

For the airwell, as it gets no direct sunlight, frosted white glass is used instead. This provides sufficient privacy for the residents, while reducing the need to turn on lights indoors during the day time as sufficient sun-light gets to enter the flat without adding to the heat. Which is both sensible, ecological and cost-effective.

Overall, these are design considerations that are more present in well designed old buildings than the new shiny ones we have today.

So, if you are thinking of ripping out your old windows, do re-think about it. Do you really want to throw away something that has stood the test of time and is suited to our climate, for a new and untested material/design?


  1. I look forward to more of such posts.

    Keep in coming!

  2. My husband and I are newbies (3 years) in the estate and have often wondered about the green glass. Thanks for sharing!

  3. Any ideas any sub-contractor still fabricate this type of steel window?