Windows, windows, windows !!
Such an expensive exercise..right?
Well yes, and no depending on who you talk to and for what time frame you are talking about. Let me explain.
Windows as a component are considered expensive because they actually are. However let us put things in perspective. We are talking for components of a building that are basically part of the building envelope as a permanent fixture, just like the walls, floors, roof/ceilings. They play a very significant role in the thermal behaviour of a home, office and any type of habitable building. Effectively glass itself has the thermal properties of a piece of copper; heat moves through it like a lightning. You cannot change windows as you would go about changing the wall colour of a room.
And here comes a very interesting point. The description of a glazing unit vs its U and SHGC value/performance. So which one is more relevant?
Well, similarly to insulation and various insulation materials such as Cellulose fibre, Glass fibre, Polyester, Wool, Polystyrene, Polyurethane, Rockwool, etc all are graded based on their thermal performance with the R-value unit. So an R2.0 of any of the above will provide an R2.0 performance. Identically, U and SHGC do just that. They provide the benchmark for the thermal performance of the glazing unit irrespective of the physical form either the unit is Single, Double, Low-E, Tinted, Sliding, Awning window, Timber frame, Aluminium frame, etc.
So always look for U-value and SHGC for a glazing unit and consider these figures more than the description of the glazing system.
Since a house is built for a few decades in mind, running costs as well as the environmental impact of the building should be a major consideration and should take precedence over a granite kitchen bench-top in cases that budget is the issue. One would ask; what is the sweet spot between spending more or less for windows? Well, thermal comfort benchmarks set by the government take part of this guess work out of the equation especially at low performing designs. Another consideration is, do I want to feel the cold in the middle of the night causing me to become unwell? Do I want my home to feel comfortable without using A/C as much or at all?
If you have any questions, please do contact me.
Thank you for reading.