The exemption for improving an existing house
Malibu's Local Implementation Plan, the zoning half of its Local Coastal Program, exempts improvements to existing single-family residences from the coastal development permit requirement in Section 13.4.1. The term covers fixtures and structures attached to the house and the structures normally associated with one, such as a garage, pool, fence, storage shed or landscaping. Guest houses and self-contained accessory units are expressly left out.
The Planning Department handles this with an exemption checklist that walks through each exception, and the applicant and owner sign a declaration that the answers are correct. If any exception applies, the project needs a coastal development permit instead. Either way, Planning signs off before Building Safety begins plan check, so we settle the coastal question at the start of design rather than after drawings are finished.
When a remodel or addition loses the exemption
The exemption does not apply when the house or the improvement is on a beach, in a wetland, seaward of the mean high tide line, in an environmentally sensitive habitat area, or within 50 feet of a coastal bluff edge. It also does not cover significant landform alteration in those places, the expansion or construction of a water well or septic system, or a house whose original permit said future improvements would need a permit.
Location near the shore adds a size test. For properties between the sea and the first public road paralleling it, within 300 feet of the inland extent of a beach, or in designated scenic resource areas, an increase of 10 percent or more in internal floor area, a height increase of more than 10 percent, or a significant detached structure such as a garage, fence, shoreline protective device or dock needs a permit. The 10 percent is cumulative, because a later improvement on a house that already used the exemption counts against it. On those lots we often size an addition around that line.
Remodel, replacement structure or new development
The Local Implementation Plan defines a remodel as an upgrade of the interior or exterior faces of a building without altering its existing foundation, footprint or building envelope. Under the plan as certified, replacing 50 percent or more of a single-family residence, measured by its exterior walls, is not repair and maintenance at all. Unless a natural disaster destroyed the house, that work creates a replacement structure that requires a coastal development permit.
That threshold matters for older homes with nonconforming setbacks or heights. The plan allows additions to a nonconforming structure when the additions themselves meet current standards, but demolition or reconstruction that replaces more than 50 percent of it generally requires bringing the structure into conformance. On parcels on the ocean side of public roads such as Pacific Coast Highway, a project that replaces half or more of the structure may also be reviewed against the plan's ocean view protections. We map which walls stay, and document it, before demolition begins.
Septic capacity and new bedrooms
Many Malibu homes rely on an onsite wastewater treatment system, and the city states that an upgrade may be required for any alteration, remodel or repair that adds bedroom equivalents or plumbing fixture units and so increases the load on the existing system. The city's Environmental Health office reviews project plans to confirm that an existing system can accommodate the proposed flows, or evaluates a newly proposed one.
This is often where a remodel's scope is decided. Converting a den into a bedroom or adding a bath may be enough to require a larger system, and expanding or building a septic system is one of the exceptions that removes the coastal permit exemption. A new system in Malibu requires a coastal development permit from Planning. We have the existing system evaluated before the floor plan is fixed, so the bedroom count you want and the system the lot can support are settled together.
Geology review for additions
The city's geotechnical guidelines, prepared with its Environmental Sustainability Department in 2013, sort additions by size. A small addition adds less than 750 square feet and no more than 50 percent of the existing floor area. Anything larger is a large addition, and large additions, along with projects in state seismic hazard zones, fault zones or hillside areas steeper than 4:1, are expected to include site-specific geotechnical exploration.
For a small addition or remodel on shallow footings, on flat ground outside liquefaction zones, landslides and fault zones, the guidelines allow conservatively assumed design values in place of a project geotechnical consultant, with continuous footings doweled into the existing ones. The City Geologist reviews the reports and plans that are required. We decide with your engineer early whether a soils investigation is needed, since it affects both the schedule and the foundation design.
Habitat, fire and the landscape around a remodel
On lots near sensitive habitat, the Local Implementation Plan excuses some work from the detailed biological study and from Environmental Review Board review: remodels that do not extend the existing footprint, and additions within the lawfully established graded pad that require no additional fuel modification. Keeping an addition on the existing pad can therefore keep a remodel on a simpler track.
City records place all of Malibu in a Very High Fire Hazard Severity Zone. In the areas it serves, the Los Angeles County Fire Department requires an approved fuel modification plan for remodeling of fifty percent or greater in fire hazard severity zones, and its Forestry Division reviews landscape and irrigation plans before construction or remodeling. We fold the landscape, the exterior materials and any fuel modification work into the same scope as the house.