ᐅ What is the recommended roof pitch?

Hello,
I would like to build a house with an exposed roof structure visible from the upper floor, featuring a shallow gable roof without an attic. What roof pitch is advisable (with the intended covering being tiles), and why? Is the following correct, and are there any additional considerations (in North Rhine-Westphalia)?

• At least 15 degrees when roof windows are to be installed (according to Velux);
• At least 22 degrees to ensure rain tightness (according to dach.de) ("classic flat roof tile");
• 30 to 45 degrees are optimal for photovoltaic panels or solar collectors (according to Thomas Königstein).

Are there significant cost differences depending on the roof pitch?

karl.jonas schrieb:

Hello,
I would like to build a roof structure visible on the upper floor, with a shallow pitched gable roof without an attic. What roof pitch is advisable (for a planned covering with tiles), and why? Is the following correct, and are there additional considerations (in NRW)?

• At least 15 degrees if roof windows are to be installed (according to Velux);
• At least 22 degrees to ensure rainproofing (according to dach.de) ("classic flat roof tile");
• 30 to 45 degrees are optimal for photovoltaic panels or solar collectors (according to Thomas Königstein).

Are there significant cost differences depending on the roof pitch?

Is there a development plan / zoning plan? What does it say?

There are significant cost differences depending on whether you build (or have built) a traditional rafter roof or a truss roof.

Furthermore, this topic might not even be relevant if you plan to build with a general contractor (GC). From my own experience, most GCs either refuse such work or charge an extremely high price for it.

However, if you build through individual contracts with an architect, it should be possible. A gable roof with a 45° pitch will likely be excluded for aesthetic reasons alone. A 22° pitched gable roof comes to mind immediately.

25° combines the best of all worlds...

We are also building with 25 and I find it almost perfect. If we could have gone a bit higher, we would have chosen 30 to have a bit more space upstairs. But 25 works well too 🙂

karl.jonas schrieb:

At least 22 degrees to ensure rainproofing (according to dach.de) ("classic flat roof tile");

You can actually achieve rainproofing with an underlay membrane already at 18 or 20 degrees.

karl.jonas schrieb:

30 - 45 degrees are optimal for photovoltaics or collectors (according to Thomas Königstein).

It depends on the orientation of the roof surfaces. East/West orientation often makes less sense.

There are pros and cons to every option. You should clearly define what is important to you: aesthetics, photovoltaic self-consumption, full feed-in of photovoltaic energy, …
I would go for about 20-22 degrees.