Have you ever wondered why so many large chain stores have two sets of doors? No, it is not just to store shopping carts.
Where I live, any home that is around 100 years old (that hasn't seen any renovations) will very likely have two front doors. Putting it simply, you open one door, step into a small space, and there will be another door in front of you.
The space goes by many names, including: arctic entry, mud room, breeze room, vestibule, airlock, foyer, and more. For sake of simplicity, I am going to call them "entry vestibules."
Entry vestibules create a buffer between the outside and the inside of the building, preventing drafts. This can help greatly with temperature regulation in both the winter cold and summer heat. I can't find number details on energy saving, but the fact that large chains still build them may hint of their importance for money-saving.
In homes, this space also typically serves as the mud room ( a place for shoes and jackets).
In the name of "first impressions," and open concept designs, vestibules are often the first thing to go during renovations, and I think that's a real shame.
Totally tracks. I first experienced these in Chicago, ie “the Windy City”. Every business has either these vestibules or a rotating turnstile type door. I didn’t get why until I came to a place without one and every time the door opened freezing cold air blasted in.
It's interesting that all the old houses used every method to save energy and costs including multiple doors, heavy curtain around windows and strategic tree placement to keep homes cool in the summer and warm in the winter. All these ideas which were super common just got forgotten or ignored. Adding these back with new better insulation materials can make a huge energy saving. Dumb that we stopped
Well businesses use them because there is so much traffic coming and going. Hope you don't have that much at your place.
I could only think that we have better weatherproofing around doors now (and better doors themselves too with better insulation). And the rest of the house is better insulated and air tight too, so less of a need. We used to have screen doors that cut the wind as well, don't see many of those but those could come back. Interesting idea but I can't really see them coming back, especially with many new houses being those small skinny houses.
It's blocks airflow when only one door is open. A cache of sorts. Insulation isn't really the issue, since a single door allows free airflow, regardless of how well insulated the door is.
It's also part of why revolving doors are useful (though those also help with stack pressure in multi-story buildings).
It does two things: 1) a cache when one door is open, 2) and prevents drafts (from improper sealing around the door) like OP said. Insulation of the door is another component of the second part.
Smaller houses had them too. I have been in a ton of houses from the early 1900s or late 1800s that had the entry vestibules.
You are right that advances in insulation and HVAC have made them less common. Another factor is people tend to come in through a garage, so there is a mud and/or laundry room there that acts in the same capacity. Older homes usually only had a back door and a front door with no garage so the main point of entry for the homeowners was the front door. Larger homes did sometimes have a porte cochere with a side entry to the home with a mud room, those houses usually had a garage built onto the home where the porte cochere was.
So I started this comment as a reply, but I felt like people would also like to hear about this as someone who cares about mud rooms when pretending I can afford to buy a house window shopping.
I grew up in a rural/small town area where mud rooms are still highly valued to this day. Small houses will also occasionally have mud rooms, even if it's just a weird little hallway. In this area, the mud room usually has built in shelving and enough space to put a shoe rack plus sometimes the washer/dryer. Most commonly, it's about the same sqft of a full bathroom if the washer and dryer aren't in there; only a little bigger if they are.
I usually see them with hard wood, tile or linoleum floors to make them easy to clean, and a cheap, rough rug from Menards gets thrown on top to wipe and leave shoes.
Another, and probably more common, thing is a covered and insulated all-season porch. Usually it has screened, cheap windows and spans most of the length of the side it's on. This has less insulating power than a mud room, but with the trade off being a socializing space while semi outdoors and bug free. In the 150 yo house I grew up in, it even had a bathroom because it was a farmhouse. This house didn't have any screens, it was honestly more like a mud room than a porch; however there's also a local terminology thing about size being important in the distinction between mud rooms and porches.
It won't be very long. The house bubble will settle over the rural Midwest. It's already begun. 3br 1bath 1k sq ft are already north of 300k. The one dollar tree in town won't support it. Trailer parks are already getting bought up by equity. We need guillotineabules, not vestibules.
I've had two houses over a hundred years old. The first was a "shot gun shack". As soon as you'd open the front door in the winter the thermostat would click. Had some front doors installed dividing the living room from what we called the foyer. It made a big difference. My house now has a mud room at the side door. I've kept the original door which I'm sure isn't energy efficient so it cuts down on draft
Basically every dutch home has one. Both houses and apartments. We call it the gang. Or hallway? It's usually where the coats are hung, toilet is and stairs are.
@Blair Older houses in my country also have them, and they're called just like that: vestibules. And what's interesting is that the buildings from the communist era also have them. I grew up with them being called simply "holul de la intrare" (literally just "the entry hallway"). Indeed, it's a place where everyone leaves their jackets and shoes so that they do not bring all the dirt inside the house. In fact, my studio has an entry hallway as well, but I rarely close the door fwiw.
Newer buildings, if I recall correctly, tend to blur this demarcation, as they try to turn everything in an open space (so that it looks bigger) - as such, there's usually no door that leads to that little hallway - probably because having an AC makes it less important to have another door after you get inside the house. But I saw that it's still properly marked by walls, so you know in your mind where to leave your shoes, your jacket etc.
I knew some folks who had this beautiful old Victorian house with a mud room. They covered the entire arched ceiling in wine corks and the floor in $153.82 in pennies.
Also, I can't wait to see the Technology Connections video on this amazing energy saving technology.
Where I am if it's inside the house, like the outer door's wall is insulated, than the room is a foyer/mud room. If it's outside the house, i.e. the outer door's wall is not insulated, then it is a sundeck.
If there is only one door and the outer area is exposed with just a railing instead of a wall it's a porch/patio.
It is very common in Montreal, that's where you take your boots and jacket off close the door behind you before opening the other, don't let the snow in.
Around me the main current use case of these rooms is for landlords who have broken up a bigger detached house into multiple units to separate these units with 2-3 doors leading off into different units.