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.
(Image Sources: Image 1 | Image 2)
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.
Nice cat airlock
Fun fact: The german term I learned for his literally translates to the “windcatch”.
Edit: It’s “Windfang” in German
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).
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.
