When you’re thinking about ways to keep the heat inside your house where it belongs, one interesting project that’s often overlooked is the vestibule, also sometimes known as an airlock.
In addition to helping you cut winter heating and summer cooling costs, vestibules can offer lots of interesting design and remodeling possibilities. They can add curb appeal, resale value, and some additional, very practical square footage as well.
The vestibule is really a simple concept. It’s actually just an entry hall or room with a door at each end. A person entering the house from outside passes though the first door and into the vestibule, then through the second door, which leads into the house itself. This two-door system, often seen in commercial buildings such as retail stores and office buildings, is very effective at trapping heated or cooled air inside the room rather than allowing it to escape outside.
While they’re often used at the front of the house, vestibules can actually be added at any exterior door. The more traffic that particular door sees, the more effective the vestibule will be in keeping conditioned air within the home.
Vestibules serve a great second purpose in keeping your house cleaner and more organized. The room traps a lot of dirt and dust before it makes its way into the house, and it’s the ideal place to set up benches, closets, hooks, storage bins — whatever you need to make a comfortable and convenient spot for people to shed dirty boots and winter coats. A less formal vestibule at the back or side of the house can even contain a large sink and counter area, perfect for messy cleanups after gardening or even your latest fishing trip.
Some design considerations
What your vestibule looks like depends on where it’s located, and how you want it to blend with your home’s existing architecture. You actually have a little more leeway with a vestibule than with other types of additions, allowing for a combination of different building materials, decorating techniques, and even landscaping. Ideally, the design should be spacious enough to feel comfortable and to accommodate whatever furnishings you’d like it to have, but not so large that it dominates that side of the house — especially if it’s in front — or that it requires heating.
One idea is to simply create a vestibule out of an existing front or back porch. If your porch is already covered, this enclosure process may be no more involved than adding three walls and a door. If there is no porch currently there, you have the freedom to create a small roofed and walled-in area in any style that compliments your home’s design.
Here are a few things to consider in your planning:
1. The vestibule’s proportions should be in keeping with the general proportions of the house. A tiny vestibule will have an out-of-place, "tacked on" appearance in front of a large house with a wide, tall front facade, while an expansive vestibule can easily dominate the front of a small house.
2. Typically, you’ll want to select roofing materials that match the existing home, while siding materials can either match or compliment what’s existing. For example, wood siding on the vestibule might be a nice compliment to a brick house, especially if you can’t match the style and color of the original brick. Likewise, stone or brick on the vestibule might be a nice compliment to a house with wood siding.
3. Use enough windows and/or skylights to keep the vestibule feeling open and bright, especially if it’s small. However, remember that the more glass the room has, the colder it will be in winter, and the hotter it could potentially be in summer. Depending on the room’s orientation, you may also want to consider adjustments in the amount of glazing; with a south orientation, more glass will take advantage of passive solar heating during the winter, but a north exposure will remain colder during the winter, so you might want to reduce the glazing. Windows should all be double-pane and low-emissivity (low-e) to keep the space as energy efficient as possible.
4. Remember, this is not a space you’re going to heat, so don’t run a duct to it. If you do, you’re simply adding square footage to your heating bill, and defeating the concept of what the vestibule is there for. However, if you add a sink, be sure that the plumbing is well-insulated, or that a small space heater is provided to protect pipes from freezing during extremely cold weather.
5. Think of the vestibule more as an outside space than an inside one. Consider easy care materials, especially for the floor. Brick, stone or nonslip ceramic tile are all good choices that also look nice. Area rugs should be nonslip and easy to clean. If you’re going with the mudroom concept, consider furniture that will be easy to clean and will stand up to water, snow and mud.
6. Ideally, try to offset the exterior door of the vestibule from the interior one. In the event that both doors happened to be open at the same time, this offset design helps prevent cold air and even dirt and debris from blowing directly into the house.
7. Finally, remember that the construction of a vestibule, even if you’re just enclosing an existing porch, is still a structural addition, and will require building permits. Check with your local building department before starting any remodeling project of this type.