As a hangar home designer, I occasionally get requests for a hangar home to be built on top of the hangar. Interestingly enough, I've not seen many of these actually built. In my own neighborhood of over 50 hangar homes we do not have a single instance of a hangar with a home on top. But throughout the Internet there are many pictures of such projects. I don't know the actual percentage of hangar homes that are built which use this format but I suspect that is a relatively low number. This may be changing. Here is one example of a home that I see popping up on the internet. As I understand it, it has not yet been built. But it is an appealing look. You might notice that the hangar does not appear to be very wide - and this is a duplex.
Placing a home over the hangar can be an excellent idea if faced with a tight (ie. small) building site. If properly designed, these types of structures can be efficiently build utilizing a relatively small ground floor area for relatively large usage space.
But on the negative side, these types of projects can look boxy. There are remedies (see below) but the nature of these structures tend to lend to a heavy "over/under" look. They also tend to force the hangars to be relatively small due to structural challenges which I will describe below. They can also quickly push the height restrictions since hangars need to be relatively tall and with the addition of a home on top can push some zoning limits. Another disadvantage is that the cars and the living area are on separate levels forcing one to use either stairs or an elevator to get up to the living space. Even two-story homes associated with hangars have a lower living level which will contain the kitchen and common living areas which is quite convenient for bringing in the groceries, accepting guests etc. It can be awkward having guests climb stairs to find the front door. If one is looking for a two-story home it is essentially impossible to do over a hangar because it will bring a height of much higher than many local zoning requirements will allow. Plus it will look very much out of balance.
The main structural challenge with a home built over hangar is that since we do not want any types of structural posts inside the hangar the hangar must be spanned by a beam of sufficient size to handle the loads. This tends to restrict the size of the hangars, either in width or depth. A reduced depth can allow us to bear the structure of the upper home on both the front and back walls and not create problematic floor joist spans. A reduced width will allow direct use of shorter structural members, again, reducing the span problem.
While beans can be easily designed to carry the required loads, the problem is, what we call in engineering, "deflection". Deflection is the tendency of a beam to drupe or bend downward as a result of the weight that it is bearing. This, in itself, is not a problem and can be controlled but it can lend to a phenomenon called "bounce". If the beam is not "stiff" enough it can cause the floor above to vibrate and bounce as a result of any type of standard human traffic. I've been in structures where this had not been properly accommodated, and could feel the floor moving and bouncing with just a few children running from one end of the structure to the other. The beams were "strong" enough to be safe but not "stiff" enough to prevent the bounce.
"Stiffness" is a function of many factors but the beam depth is a big one. The key solution to reduce bounce is to design the beam to maximize its depth. Its depth has to be significant compared to its length. The longer the beam, the deeper it must be.
There are ways to do this. A beam can directly be chosen due to its substantial depth but this can be an architectural challenge in that it might protrude quite a bit into valuable spaces. Another way is to "skin" a strategic wall in the home above and letting it act as a deep beam unto itself. This can be cleverly designed and can certainly handle the situation. In these types of beams, depth is more important than weight.
If one is looking to have as living quarters above the hangar, the easiest solution is to build a smaller hangar, either in depth or width. If an owner is happy with the hangar size such as this, it can be an excellent way to proceed.
To handle the boxy look one can add facade features as well as design outcroppings to add interest.
In my experience, the majority of hangar home owners like to have their homes look like a typical residence and to de-emphasize the overwhelming effects of the hangar. With good architectural design this is relatively easy to achieve. It is easiest to achieve when the home and hangar are spread over a larger site which allows the architectural elements of the hangar and the home to gracefully blend. Personally, this is my favorite way to attack such a project.
If you are looking to build a hangar home, certainly do not hesitate to consider every option available. An experienced hangar home designer can surely help. Whether you choose a side-by-side hangar home structure, or choose to place the home over the hangar, an excellent solution can always be found.
See Additional Articles on this subject. Home over Hangar Arrangements.
