In March 2008, the City of Los Angeles enacted the Baseline Mansionization Ordinance in response to an overwhelming public outcry to stop building McMansions on small lots. The ordinance implemented restrictions on the size of a home that could be built above ground, thereby reducing the architectural mass of a home visible within the neighborhood. This was done by establishing limits of size based upon lot area and zoning designation with a sliding scale of percentage floor area ratios (FAR). For example, if you have a 7,000 square foot lot in the R-1 zone, the ordinance provides for a maximum home above grade equal to 50% of the lot area or 3,500 sq. ft. In addition the ordinance provides for an additional 400 sq. ft. of garage area, 250 sq. ft. of exterior covered patios and 250 sq. ft. of detached accessory structures. Furthermore, the ordinance provided for a 20% bonus if one of two building articulation features were incorporated into the design or if LEED Certification was accomplished. Since a basement, fully below grade and hence, not visible in the neighborhood, is exempted square footage from the ordinances size limitations, a natural outgrowth of the new code is a sharp increase in the number of basements being built in Los Angeles. Structure Home has completed 6 basements in client homes since the code became effective and we are currently building two new basements with two more in the planning and permitting phases.

From the standpoint of architectural design, the trend of basement construction offers some great advantages. First and foremost, and consistent with the positive intentions of the anti-mansionization movement, reducing the mass of a building by pushing square footage below grade creates better looking streetscapes in the neighborhoods within our community. In addition, the design and functionality of a home can be enhanced in several ways. To begin with, basements typically house play rooms, gyms, home theatres, offices/studios, guest quarters, wine cellars, storage and the like. This organization of space not only improves the function of the home by segregating these types of uses to a more private space within the home but also opens space on the prime above-grade living areas thereby improving the quality of the space enjoyed by the whole family on the first and second floors of the home. Therefore, basements offer significant advantages that make them even more attractive to the discerning custom home client.

Since a basement is livable area built below the surface of the ground, there are several challenges that must be addressed including sub-grade excavation, soil export, protection of neighboring improvements, waterproofing, light and ventilation, emergency egress, water/sewage ejection, etc. As a result of the best practices employed to properly build and anticipate all of the physical circumstances inherent in sub-grade construction, the cost of basement space is higher and the time to complete a home is longer. These are the obstacles that a client wanting the advantages of a basement must overcome. On a positive note, the building technology and products available to mitigate the potential issues with this type of construction are so far superior today than ever before that basements properly executed, can and do provide beautiful living areas that feel as much a part of the home as the above ground areas. Hence, the value of the space is arguably as valuable as the portions of the home above ground. In fact, every Structure client who builds a basement...loves the space for all of the benefits it brings to the quality and use of the home.