ᐅ Oversizing of Window Openings

Hello everyone,

When measuring for facade work, it is generally standard practice (according to VOB) to include window areas smaller than 2.5sqm (27 sq ft) in the total surface area, meaning these are not deducted.

So far so good.

Now I have been wondering to what extent a window directly adjacent to a balcony door can be deducted. To illustrate this, I have attached a drawing: the window and balcony door are directly connected (no reveal or similar in between), with the frames of the door and window directly adjoining.

Individually, the areas are 2.1sqm (23 sq ft) for the balcony door and 1.9sqm (20 sq ft) for the double window, meaning they would normally be included in the measurement. However, it seems logical to me that this combined area should be deducted.

In various quotes, the estimated total surface areas vary significantly (more than 30sqm (323 sq ft) difference between the lowest and highest quote).

Perhaps this could be a point worth discussing?

As far as I know, the opening is considered as a whole, since what matters is not the installed component but the opening itself. In my opinion, this opening should not be oversized. However, it is possible that the reveals might be calculated separately.

I basically see it the same way. The VOB states that openings, niches, etc., up to 2.5 m² (27 ft²) in individual size are measured separately. One could, of course, argue that windows and balcony doors each consist of two separate parts and should therefore be considered individually... However, I also agree with Koempy that the opening itself should be counted.

With a total area of 300 m² (3,229 ft²), 30 m² (323 ft²) equals a 10% "error." This cannot be explained solely by your element. You should ask around...

Yes, I will definitely inquire again. It is not 300 square meters (3,229 square feet). But there are several such cases in total, amounting to about 15 square meters (161 square feet).