Other Items You May Need
Meeting Geographical and Site Specific Requirements
These plans, and associated documents have been prepared to comply with the latest adopted base code version of the International Residential Code (IRC). Typically, states adopt the base code with their own adjustments. For example, the State of Washington regulates residential construction under the Washington Residential Specialty Code, which is based upon the IRC, with specific adjustments to meet unique requirements within Washington.
Each state’s unique requirements vary – many related to climate or seismic conditions within the state. These plans comply with base codes for fire/life/safety requirements. Additional structural sheets are available to address wind/seismic requirements of the states of Oregon and Washington. For other states, or countries, it will likely be necessary to work with an engineer to comply with the structural requirements of the location.
Many jurisdictions also impose energy efficiency requirements that are unique to the climate. In such cases, additional drawings, details, calculations and worksheets may be necessary in order to obtain a permit. Often the general contractor, working with HVAC and/or insulation sub-contractors, will be able to meet the compliance requirements.
Each state in the US adopts a building code as their base code. Over the years, there have been several national code standards for states to choose from, but now the International Residential Code has become very widely accepted as the standard base code. For this reason, we choose to follow the IRC in developing our plans. Unfortunately, each state can modify the base code with their own state adopted amendments, and may choose not to adopt certain sections of the base code. Energy requirements are a common section that is heavily modified or replaced by a different model code, by each state.
So, meeting the myriad of national, state and local codes can be a challenge. These plans will likely require additional information before being ready to submit for permits. A great place to start is with your local building department, where you will be obtaining your building permits and inspections. Most building departments will have a website, brochures or handouts which describe the submittal requirements that will need to be met. In a few states, all plans must be created or reviewed by a design professional – such as an engineer or architect – who is licensed in that state.
It is wise to allocate additional coordination time, and budget, to meet these requirements. Our staff knows to never promise that our plans, without modification, will meet every requirement of every jurisdiction in the country. The reality is that additional information is likely to be required, and we may not meet the qualification requirements (state licensing, etc.) to address those cases for the customer. We do offer follow-up support, via telephone and email, to address as many code-related issues as we can.
The base code requires that the design of your structure meet certain requirements. The code allows for a couple of ways to meet these requirements. The first method is known as “prescriptive” wall bracing, and is built into the code as prescribed building elements that must be included at specified positions of the building. Prescriptive methods are acceptable as long as the structure’s design fits within certain limitations (wall height, window size/location, etc.). The second method is to demonstrate, by engineering analysis, the forces imposed upon the structure, and the design of structural elements to withstand those forces. Whereas the prescriptive method imposes certain limitations on the design of the structure, the engineering analysis of the building allows for greater flexibility in the design, while ensuring it can withstand the actual natural forces the structure will experience.
In almost all cases, Home Plans NW designs will require engineering analysis (not designed to prescriptive method). This analysis is required to be conducted by a professional, such as an engineer, who is licensed by the state in which the structure will be built. Furthermore, the analysis is specific to the exact building site – for this reason, we do not have “pre-engineered” plans that can be built anywhere. An engineer will need to review the plans and provide an engineering analysis report and additional drawings and specifications to go along with your plans for permit submittal. You should allow for additional time and expense to complete this process.
When the design includes retaining walls, these will also require engineering. Although the code provides for some prescriptive basement and concrete/masonry wall designs, these only work in limited situations. The use of site-engineered retaining walls allows for much greater design flexibility and ensures that the walls are designed specifically for the design loads, unique soils, fluid pressures, and drainage characteristics at the building site. It makes little sense to place the most expensive investment a family typically makes onto a foundation that is not designed for the unique characteristics of the land on which it is set.
The physical characteristics of the building site may necessitate additional analysis by licensed professionals, such as engineers, geologists, or even archaeologists. A geo-technical engineer may be required to assess the risks of ground movement and the impact of ground water on the design of the structure’s foundations, for example. These issues can be especially challenging where certain soil types are involved, or where faults, slides or other surface features are expressed. The probability/risk of things like flood, wildfire, landslide, high wind or earthquake should be considered and analysis of how to address these concerns may be required as part of your permit process. In some cases, historical preservation, ecological conservation or some other restriction may come into play. It is recommended to check with your planning department to review any known concerns, well ahead of obtaining your plans and starting your project.
Development Code and Design Standards
The rules of the municipality for the regulation of development and construction are spelled out in the development code. Within this code, rules about allowable size, location, construction type, function, access, and aesthetics of new structures are typically included. Design standards provide further detail on the form and aesthetics of the structure, including such things as position and size of garages, location of entry, the inclusion of architectural features, and certain minimum sizes of spaces and features like yards and porches. Visit your planning department or its website to locate and review the development code and design standards before you begin your project so that you can make sure the design you have chosen will meet all requirements; otherwise, your project will be delayed and require revisions before it will be permitted.
Energy Code and Building Envelope
The IRC model code includes energy code and building envelope specifications for climate zones across the US. In this section, information such as insulation R-values, window U-values, and envelope sealing are covered. This section of the model code is commonly modified or replaced by states, counties, and municipalities. In some localities, additional paperwork, calculations, and/or building heating/cooling modeling may be required. Check with the building department to verify the requirements where you intend to build. In some cases, it may be necessary to hire a qualified consultant to complete the compliance requirements. It may be necessary to modify the design to meet requirements, once the design has been analyzed with respect to the local energy code requirements.
Many subdivisions include Home Owner Associations (HOA), which impose additional requirements and reviews that you will need to satisfy, even if you have obtained your building permits. Depending on the scope of the HOA rules, it is possible that you can be required to alter the house design that you propose to build. For this reason, it is important to check with your HOA before you complete your house design work, and before you submit for your building permits. Even if you are not regulated by an HOA, there may be other design covenants and restrictions that apply to your project.
Experience and data gained over years of fighting fires have revealed that the size of the structure impacts the success in limiting damages and injury. The larger the structure, the greater the volume of water that is required in order to suppress a fire. Depending upon the location of your building site and the availability of water resources in order to fight a fire, additional fire-related features may be required in the design of the structure. Fire separation of spaces, the incorporation of fire-resistant materials, or even the addition of fire sprinklers may be required for your project. Check with your building department or fire marshal, especially if the structure you plan to build is relatively large. (Size may vary by location, but greater than 3,000 sq. ft. is often large enough to require such measures.)
The site plan drawing shows your property boundaries and the proposed position of the house, including its height. How much detail is needed on this drawing differs with each jurisdiction. Typically, an accurate outline of the house, including the location of the garage and overhanging rooflines, balconies, or decks, is required. Dimensions from the house to the property lines will be required. Also, information about the slope of the property, such as elevation marks or grade contours, and the location and extent of the driveway, walkways and patios are typically shown. Check with your permit jurisdiction – they will often have a handout describing what is required on the site plan. Your builder may be able to coordinate this information for you. In some cases, more than a basic site plan may be needed. If your house is not connected to a municipal sewer and water system, you will need to provide detailed information about wells and septic fields. Other items may include documenting site drainage, trees, and vegetation; site surface grading; preservation of sightlines; shadow studies to verify solar access on adjacent properties; etc.