Engineering is the profession aimed at modifying the natural environment, through the design, manufacture, and maintenance of artifacts and technological systems. It might then be contrasted with science, the aim of which is to understand nature. Engineering at its core is about causing change, and therefore management of change is central to engineering practice. The philosophy of engineering is then the consideration of philosophical issues as they apply to engineering. Such issues might include the objectivity of experiments, the ethics of engineering activity in the workplace and in society, the aesthetics of engineered artifacts, etc.
Engineering is the practical application of science. This is accomplished through knowledge, mathematics, and practical experience applied to the design of useful objects or processes. Professional practitioners of engineering are called engineers.
Residential frame engineering typically involves the structural engineering design of the frame structure of a house. Rather than a set of structural plans drafted by an architect or lumber supplier, engineered framing plans are developed by a licensed engineer.
A typical set of engineered drawings for a house will include - Roof framing, Ceiling joist framing, Floor joist framing, Wall bracing and General notes and details.
The level of detail to which a roof system is engineered varies greatly among engineers. At a bare minimum, the roof framing plans should show the rafter layout, specify the size and spacing of the rafters, and specify the allowable span of the rafters. Some engineers today provide only this minimal amount of detail on the roof framing plans they generate. Other engineers provide a much higher degree of detail. In addition to the items mentioned above, they show the location of all roof supports (i.e. struts) and show all purlins with dimensions to tie down their location. Generally speaking, the more detailed the roof framing plan, the higher quality the roof frame engineering.
Ceiling joist framing
The ceiling joist layout shows all of the ceiling joists over the rooms (typically over the second floor of a 2-story house, or over the first floor of a 1-story house). The size of the joists will vary depending on the spacing of the joists, as well as the span. Whether or not the joists are designed for attic storage loads will also affect the size of the members.
Depending on the location of the project, the type of lumber used may vary. The allowable spans for several common lumber species can be found in the 2015 International Residential Code, published by the International Code Council.
Floor joist framing
The floor joist framing layout looks similar to the ceiling joist layout. However, where the ceiling joists may consist of 2x6s, 2x8s, 2x10s and 2x12s, the floor joist layout will typically show 2x12 joists only. In some cases, where loads and spans dictate, and deeper floor joist system may be required. Deeper floor systems include wood I-joists and open web trusses.
Wall bracings plans specify the amount and type of sheathing or lateral bracing that is needed for the house to withstand the applicable design wind speed. In higher wind speed areas, the wall bracing plans may additionally specify embedded or post-installed hold-downs, pre-fabricated steel wall panels, steel moment frames, etc.
General notes and details
The general notes and details will contain standard construction recommendations and typical construction details. General notes and details provide information that supplements the structural drawings.
There are several benefits to having residential framing plans engineered. Some of these benefits include:
Load path analysis to ensure roof loads are properly and efficiently transferred down to the foundation
Value engineering - beams with significant spans are designed for bending capacity and their deflections are checked using engineering analysis, and are not simply taken from a table based on historical precedence
Value engineering means better performance while minimizing costs
Fewer delays obtaining permits and during construction
Peace of mind knowing the structure complies with code and sound engineering principles