Patio Covers, Carports and overhangs

A 4' or more roof overhang can be designed into the roof truss itself. These are great for providing extra shade on the home and additional space to install solar panels on the roof. Of course, if the overhang get large enough, it will need extra supports but that is just part of the design. 

The biggest problem with large overhangs is it increases the uplift forces from the wind. Roof trusses must be heavier duty than normal and very securely fastened to the structural frame. This also presents a slightly higher fire risk if involved in a wildfire situation. Using the proper, non-combustible materials significantly reduces that risk. I would only recommend overhangs greater than 2' on single-story levels. You loose much of the comfort provided by a large overhang if it is 2 or 3 stories up. However, if you have a 2nd level wrap around roof deck the larger overhang is effective again.

The overhang (or eves) in an Ironwood Home are always boxed in with full length vents, designed to prevent insects and burning embers from getting in. This is a great place to install exterior perimeter lighting, outlets for holiday lighting and security cameras. 

Patio covers, whether used on the ground floor or over a roof deck, are essential to outdoor living space comfort. They are also my preferred location for solar panels and water heating however it is probably not enough space for all of them. 

I am undecided if we should attach the patio cover to the main home structure or build it as a self-supporting system. If we attach it, there are increased pathways for thermal transfer to the interior of the home and for water leaks into the walls. Because the patio cover will move more in the wind and expand and contract daily it will open up these pathways. A free-standing structure will place posts near the building and take away some of the clean look of the exterior. Coordinating the location of these posts is critical so one does not end up in front of a window. I'm leaning towards attaching the inboard side to the roof trusses, not the exterior wall since the roof structure already has a thermal break from the interior of the home. The risks here is high-wind conditions. The roof attachment increases wind loads on the roof itself. It really comes down to where you are building and the predominant weather conditions.

I am a big fan of carports, preferred over a garage. That may be because I live in California where shade and a little cover from the rain is most important. I have never used a garage to park a car. They always become storage and workshops but are were not designed for that use. Now I design large storage rooms and workshops into the home and carports next to it. This make future remodeling of the interior easier. A garage has a depressed slab from the rest of the home, if you want to turn the garage into an extra bedroom you will either fill in that depression or live with the step up and down. If it was always level with the home it feels more natural.

The carport is an excellent place for more solar panels. My dream design is a solar covered carport with it's own battery pack. The solar charges the batteries during the day and the batteries charge my car over night.

Carports are much less expensive to build than adding 1 or more structural frames. They don't need a concrete drive surface and it removes the need for rated walls between the garage and home. None of these are hard to do but if you are looking to build the most home for the least money, everything counts.