Why additions make sense in El Segundo
El Segundo's R-1 zone sets a minimum lot area of 5,000 square feet and a minimum lot width of 50 feet, and it allows an overall floor area ratio of 0.60. On lots like these, an existing home often has room to grow before it reaches the limit, which makes adding on a practical alternative to moving or rebuilding.
We design additions that respect those numbers from the start, so the project you price is the one the city can approve. That usually means deciding early whether to extend the ground floor, add a second story, or combine the two.
How the R-1 floor area rules work
Total building area on an R-1 lot cannot exceed a floor area ratio of 0.60, and the second floor of the main house is capped at 0.25. Floor area is measured to the inside of the perimeter walls and counts every floor of the house, attached and detached ADUs, habitable attic space, accessory buildings, and most balconies, decks, verandas and porches.
Several items are excluded, including basements as the code defines them, up to 500 square feet of garage, detached accessory structures of 120 square feet or less, and low first-floor decks and porches. Rooms with a floor-to-ceiling height of 14 feet or more are counted on both stories, so a double-height living room uses more of the allowance than its footprint suggests. We tabulate existing and proposed area on the site plan, as the city's submittal requirements ask, before drawing the design.
Height, setbacks and keeping it one home
In the R-1 zone, a pitched roof may reach 32 feet and a flat roof 26 feet, with no more than two stories. The front setback is 22 feet, side setbacks equal 10 percent of the lot width but never less than 3 feet or more than 6 feet, and the main house keeps a 5 foot rear setback.
An addition, other than a garage or an ADU, must share a common wall with the existing home and be internally integrated and connected to it. A detached studio or home office therefore has to follow the accessory structure or ADU rules instead, and we help you pick the path that matches how you will use the space.
Older homes and the 50 percent wall rule
Some older homes no longer meet every current setback or standard. Under the city's nonconforming buildings chapter, such a home can still be remodeled or expanded as long as no more than 50 percent of the original exterior perimeter wall height is removed, demolished or replaced, and the foundation stays in place. Go beyond that, and the entire building must be brought into conformity with current standards.
That rule decides how much of the old house a project can open up, so we map which walls stay, which come down, and how new framing ties in before demolition begins. The Director of Community Development may grant an administrative adjustment for life safety repairs or upgrades that exceed the threshold, but it must be granted before any wall beyond the limit is removed.
Building for airport noise
El Segundo sits next to Los Angeles International Airport, and since 1993 the city's Residential Sound Insulation Program has treated 1,905 homes for aircraft noise. The airport operator now administers the LAX program for eligible homes within designated noise contours.
For new buildings and additions, Building and Safety requires compliance with noise standards when a project falls within an RSI zone, using separate checklists for the 65 to 70 dB zone and the 70 dB and higher zone. We check your address against the city's RSI map early and specify windows, doors, wall assemblies and ventilation that meet the checklist for your zone.
Plan check and how we build your addition
Building applications, plans and documents are submitted through the city's E-Z Permit Hub, and plans are routed concurrently to the departments that review them. The city aims to complete Accelerated Plan Check within seven working days of fee payment, while Regular Plan Check is listed at one to four weeks depending on scope. Electrical, mechanical, plumbing, grading, demolition and retaining walls may need separate permits, and shoring plans may be required for excavations deeper than four feet or that remove support from a neighboring property.
Contractors and subcontractors working in El Segundo must hold a valid city business license, and the approved plans and permit cards stay on site for every inspection. We handle the submittal, corrections and inspections, plan the sequence with you, including whether you can stay in the house during parts of the work, and give you a written scope and price before construction starts.