ᐅ How many windows should a house have?

roookeee schrieb:

based on the state building code

roookeee schrieb:

based on DIN EN 17037, which suggests 20-25% as a general rule of thumb

But these are only guidelines!
They apply to living spaces. Although a bedroom is also a living space, if you only use that room for sleeping, then a 15m² (161.5 sq ft) bedroom with average window size is sufficient. In contrast, a multi-purpose or living room can benefit from significantly more window area, considering that you do many activities at the dining and living room table. Also, a good distribution of windows based on knowledge of the sun’s position in the north and south is important. Natural light supports well-being and good visibility.

roookeee schrieb:

Of course, I could just take the standard floor plan from the builder, then it meets 10% of the state building code everywhere, and on the upper and ground floors each room only has windows facing one direction 🙂 But I don’t want to live like that.

Then you need to hire an architect who will design a light-filled house for you.

roookeee schrieb:

So now we ask ourselves

Why ask when it comes to common sense?
Where there is a window, you don’t need artificial light during the day. A storage room can do without a window. But if you enter that room 10 times a day, at least a small window is helpful so the light switch does not wear out. In the kitchen, daylight is nice where you will likely stand and work or prepare food about 10 times a day. For children’s rooms, two windows on two walls are ideal because they light the room more evenly for various activities, although that’s often not possible.

I would never measure just the glass with a tape measure. The window size is considered the relevant guideline.
And if you plan or have planned the floor plan with some common sense, it is designed around daily routines. Everyone knows they feel more comfortable in a room with daylight than in one with a small window. Each of us has lived in apartments or houses and understands windows and light incidence.
And as I understand it, this is about a normally sized single-family house without extra wings or studios, not a status symbol where the house blends into the forest or anything like that.
If you already have a floor plan, you can ask here in the appropriate subforums — one should also consider whether you have a sense for designing exterior facades and partition walls or not.

WilderSueden schrieb:

If you need to discuss something, the best approach is to sit down with the architect and talk about whether window X can be enlarged or if a window can be added at location Y. The architect can usually answer that quite well based on experience. An experienced architect also makes sure that the windows on different floors don’t look randomly arranged but appear harmonious.

Well, this isn’t really about custom planning, but rather the fear of not recognizing a "lower quality" general contractor’s proposal:

roookeee schrieb:

Of course, I can just take the standard floor plan from the builder with 10% compliance to the regional building code everywhere [...] If they only want to sell us the minimum building code requirements to save money [...]

The idea that a builder would increase their margin by reducing window area is unrealistic. I have never seen “window area according to DIN” or “lighting provided on site” listed in any scope of work description, even from low-cost providers.

roookeee schrieb:

Unfortunately, I couldn’t find anything about this online, which is why I’m asking here.

If you find absolute silence on a topic even on the vast internet, either you’re using the wrong search terms or (more likely here) you’re the only enthusiast interested in this. Not a single home provider advertises exceeding standards for window areas (to put it very bluntly: “not a single one at all”)!

---

https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/

roookeee schrieb:

Of course, I could just go with the builder’s standard floor plan, which means meeting only the minimum 10% building code requirement everywhere and having windows facing only one direction per room on both the upper and lower floors 🙂 But that’s not how I want to live. It’s not about designing everything ourselves, but about being able to communicate effectively, to talk about it even as amateurs, and to suggest special requests like more natural light. If the builder wants to push the bare minimum code just to save money, but doubling that would clearly be better and we could save money elsewhere, I want to be able to bring that up.

Wow. So you plan on having two windows per room?
Keep in mind that windows also strongly influence how you can furnish a room effectively.
By the way, light can also be a nuisance... when watching TV, working on a screen, or sitting at the table...
In my office, I have a window facing south, and I sit perpendicular to the incoming light. Do you think it would make sense to have another window "behind" my desk on the west side? Probably not, right? 😉
And in the living room, on the south wall where the TV is mounted, I don’t have a window either 🙁

If you want to participate in the discussion, you need to get familiar with the topic. Buy the standards and get started. No one can do that for you in just a few lines on a forum.

But to approach this just from the perspective of minimum building code requirements… are you an engineer at Audi or Siemens? 😉

WilderSueden schrieb:

You’re overcomplicating it. Even as a layperson, you can usually get a feel for whether a room will be bright or dark. If there’s a need for discussion, the best approach is to meet with the architect and talk about whether window X can be enlarged or if a window can be added at location Y. They can usually answer that quite well based on experience. An experienced architect also ensures that the windows on different floors don’t look randomly placed but appear harmonious.
Basically, in a one-and-a-half-story house, you naturally have a slight disadvantage. And also if you want a closed kitchen.

Thank you, that helps. For the moment, we will plan to make some of the currently planned windows a little bigger and reserve some budget for additional windows that we currently consider a nice option, so we will have enough flexibility in our discussion with the architect.

ypg schrieb:

But these are only guidelines!
And they apply to living areas. Although a bedroom is also a living area, if you are only using the room for sleeping, a 15m² (161 sq ft) bedroom with an average-sized window is sufficient.

Thanks for this as well; this kind of assessment helps us better categorize things, and it seems we overlooked the part about living areas several times.

11ant schrieb:

The idea that a home builder would make their profit by reducing window area is unrealistic. I have never seen phrases like “window area according to DIN” or “lighting by the builder” in the description of construction work, even with discount providers.

In my opinion, some home builders do promote standard floor plans that really only include the minimum number of windows. Of course, this can depend on the price segment of the provider, that’s true. For example, kitchens that wrap around a corner often only have windows on one wall, and those windows tend to be quite small. But our perception of the construction sector may be quite selective here.

xMisterDx schrieb:

No one can answer that for you in just a few lines on a forum.
But approaching this based on the minimum requirements of the regional building code... are you an engineer at Audi or Siemens? 😉

Of course, the first thing we thought when we started planning our house was: read the regional building code first, and THEN decide what we want / like / consider reasonable, so you’re definitely right!
The question here in the forum was about orientation, not exact specifications (as described in the initial post). Some of the answers have already helped to put things into better perspective.

No regular homebuilder reads a state building code at the start of their research—usually only when something in their specific development plan seems questionable and they want to understand how far the local authority is stretching the rules beyond the state building code’s standards. I advise prospective builders in all federal states except Mallorca, and I have never read through a state building code without a specific reason. It’s a reference book, not a novel!

roookeee schrieb:

In my opinion, some home builders promote standard floor plans that really only have the minimum number of windows. This might, of course, relate to the provider’s price segment, probably true. For example, there are often kitchens that extend around a corner but then have windows only on one wall, which are usually quite small. Our perception of the construction area can naturally also be very selective.

I would rather call it looking through a distorted lens. Not a single provider advertises floor plans with only a minimal number of windows (and as I already said, they have no interest in cutting corners there). Catalogs promote competitive models across all price segments. The most frequently cited floor plans are those considered attractive and often used as a basis for custom designs. A provider who skimped on windows there would be cutting off their “marketing channel via image platforms.”

roookeee schrieb:

For now, we will plan some currently planned windows slightly larger and hold back some funds for optional extra windows, which we currently view as a nice variant, so we have enough flexibility in discussions with the architect.

You have—at least if you mean the draftsmen or technical specification assistants from the providers—a romanticized idea of “architect meetings.” Better show here what you have planned so far—then you will get more concrete advice than you might want ;-)

---

https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/

11ant schrieb:

No regular homeowner reads a state building code

Oh… is that so? I disagree.

11ant schrieb:

I advise prospective builders in all federal states except Mallorca

But certainly not all of them!

11ant schrieb:

It’s a reference book, not a novel!

That’s why you can still take a look at it, read it… even if only by skimming.

roookeee schrieb:

In my opinion, some home builders advertise standard floor plans that really have only the minimum number of windows.

They actually advertise houses with lots of extras. The valid scope of work description for the standard model is usually much more basic. You’re probably referring to the cheapest model of a series with a starting price.
Windows might be the most visible feature. However, every trade includes a standard version; what is considered comfort is usually available at an extra cost.
Tip: there are also general contractors who don’t charge separately for windows.