Generally all buildings either, new or additions, need to address each of the above items. Structural matters  relate to the ability of the building to stand-up under its own weight and the weight of the items in the building; earthquake or lateral concerns relate to the ability of the building to withstand the forces of an earthquake or during a large storm; and finally energy concerns relate to the efficiency of the building in its utilization of fuel.  Each item is reviewed by the regulatory agencies during the checking process and, therefore, needs to be addressed in your package to the government agency to allow you to secure a building permit.
 

STRUCTURAL DESIGN

Structrual compliance occurs when all the wood members of the building are sized for (that is determined to be able to carry) the particular loads (weight) required.  The loads start occurring at the roof and accumulate as they move down to the ground as additional loads i.e. floors, walls, etc. are added. All loads must be carried all the way to the ground.  Then the foundation is designed based on the total loads from the roof to the foundation.  The Uniform Building Code has determined some basic and standard loads for buildings and the sizes of the structural elements in those situations, but they are only for general situations. Additionally, rules thumb and code minimums exist for residential construction, i.e. one story foundations are 12" wide; two stories are 15" and three stories are 18" wide, but these are only general average conditions, so if you are planning something unique or out of the normal simple construction, these conditions will need to be checked proven to the building department. This is accomplished with structural calculations that are prepared a licensed architect or engineer and submitted to the agency for approval.
 

EARTHQUAKE DESIGN

Earthquake approval is similar except that the concern is for lateral loads rather than vertical loads. In lateral the concept is to insure that the building can absorb overturning (attempts to push the building horizontally, or off its foundation). The idea is to have the structure resist those forces through shear Walls, braced frames or moment frames, that are then connected to the foundation through hold downs. A shear I is a solid wall with a plywood covering that has been nailed to the studs in a certain way. A braced frame is a stud wall with an angled brace running diagonally through the wall. A moment frame is usually a steel member that is placed in the construction that has rigid connections at the corners that resist bending. The least expensive is a shear wall and the most expensive is a moment frame.
 

ENERGY DESIGN

Energy concerns are addressed by using a passive system or an active system to heat or cool the house. In an active system a device like your furnace is used to create heat and it uses fuel to do so. Under a passive you use the sun, and convection currents to heat and cool the house. This does not use fuel, however it is very difficult to construct a totally passive house. Therefore, knowledge and utilization of passive system supplemented by an active system is recommended. The amount of passive reliance will depend individual desires and aesthetic concerns. Insulation, dual pane glass, thermal massing, and ventilating are passive systems, whereas baseboard heat, forced air furnaces or radiant heating supplied from a boiler are active systems. Usually active systems are less expensive at purchase but cost more to operate. I Therefore, life cycle costing is a relevant topic in making a decision on the type and extent of a system used. In addition, the State of California has limited the amount of energy a residence can use based on its size and the project must show, through calculations, that the project complies with the law ( Title 24).