Regulatory Compliance and Permitting in Canoga Park
Converting a Canoga Park garage into a legal Accessory Dwelling Unit requires strict compliance with municipal building codes, hydraulic calculations, and mandatory field inspections. We navigate regulatory approvals through local agencies to ensure every rough-in and finish plumbing assembly meets health and safety mandates. This systematic process transforms non-habitable storage space into a fully functional, legally compliant residential living environment.
Operating within ZIP codes 91303 and 91304, our plumbing projects adhere directly to the California Plumbing Code and local municipal amendments. The city enforces rigorous oversight across sanitary drainage, potable water delivery, and natural gas distribution to protect structural integrity and municipal water infrastructure. Securing civil permits prior to sawcutting or pipe installation remains essential for avoiding stop-work orders and ensuring successful project closeouts.
LADBS Plan Check and Inspection Requirements
Obtaining plumbing approval for a garage conversion requires submitting detailed engineering schematics for plan check review prior to starting construction. We prepare complete hydraulic calculations and isometric line drawings to pass plan review at the municipal building department. Once permits issue, our installations must successfully undergo two mandatory on-site municipal inspections to earn final operational certification.
Before physical excavation begins, detailed architectural and mechanical plans undergo review at the local department branch or online portal. Plumbing submittals must include explicit engineering schematics that outline structural load distribution and spatial layout. We compile comprehensive submittal packages that eliminate plan review revisions and keep project schedules on track.
- Drainage Fixture Unit load calculations verifying downstream main line sewer capacity.
- Isometric line drawings for domestic water supply, waste line, vent piping, and natural gas lines.
- Precise spatial routing for main water shut-off valves dedicated exclusively to the conversion unit.
- Exact locations for backflow preventers, cleanout access points, pressure-regulating valves, and seismic gas shut-off valves.
Once plans receive municipal approval and work permits are active, inspectors conduct two mandatory on-site field reviews. The underground and rough-in inspection occurs while concrete trenches, wall framing, and ceiling cavities remain fully exposed. Piping networks must pass a hydrostatic water pressure test consisting of a 10-foot head of water column or a 5 PSI air test to confirm zero leakage prior to backfilling or drywall installation.
The final plumbing inspection takes place after all fixtures, trim, water heating units, backflow devices, and shut-off valves are fully installed and connected. Our technical teams verify that every fixture operates within design pressure and flow parameters before requesting the final sign-off. Obtaining this final approval allows the city to issue the Certificate of Occupancy for the residential conversion.
Title 24 and CALGreen Plumbing Mandates
California Title 24 Energy Efficiency Standards and CALGreen environmental mandates enforce strict flow rate limits on newly permitted garage conversion plumbing fixtures. We design low-flow potable water supply systems that maximize efficiency while maintaining optimal working hydrostatic pressure. Meeting these green building codes reduces energy consumption, conserves municipal water resources, and ensures immediate permit approval.
Residential plumbing fixtures installed across San Fernando Valley conversions must meet specific operational flow thresholds under environmental state regulations. We select high-efficiency fixtures certified by the Los Angeles Department of Building and Safety to guarantee full compliance during final inspection. These efficiency caps ensure optimal resource conservation across the property.
- Water Closets (Toilets): Maximum 1.28 gallons per flush utilizing high-efficiency dual-flush or single-flush technology.
- Bathroom Lavatory Faucets: Maximum 1.2 gallons per minute evaluated at 60 PSI static pressure.
- Kitchen Faucets: Maximum 1.5 gallons per minute evaluated at 60 PSI with temporary 2.2 gallons per minute spray bursts.
- Showerheads: Maximum 1.8 gallons per minute evaluated at 80 PSI requiring pressure-balance shower valves to prevent thermal shock.
Sub-Slab Plumbing Rough-In and Concrete Trenching
Installing drain, waste, and vent lines beneath an existing garage slab requires precise diamond sawcutting, dirt excavation, and structural base restoration. We break through concrete pads to embed underground piping networks at correct gravity slopes before backfilling and repouring high-strength concrete. This process establishes sanitary drainage paths without compromising the foundation strength of the converted building structure.
Garage foundations in Southern California were poured as solid concrete slabs-on-grade intended strictly for vehicular parking and general storage. Converting these utility structures into habitable living quarters demands full sub-slab excavation to place underground waste lines for kitchens, bathrooms, and laundry facilities. Our structural trenching protocols preserve foundation stability while accommodating all necessary drainage infrastructure.
Slab Cutting, Excavation, and Structural Support
Sub-slab rough-in requires mechanical diamond sawcutting, controlled earth trenching, aggregate bedding, and moisture barrier restoration. We sawcut precise channels along planned drainage routes, excavate soil to required depths, and cushion piping on aggregate sand beds. Restoring the sub-slab vapor retarder prior to concrete repouring prevents sub-surface moisture from penetrating the new interior living space.
Our technical crews execute sub-slab excavation through a disciplined, step-by-step structural procedure:
- Diamond Saw Cutting: We utilize diamond-blade walk-behind saws to cut clean 12-inch to 18-inch wide channels along designated drainage runs.
- Soil Trenching and Bedding: Soil is excavated to depths between 12 and 24 inches, followed by placing a 4-inch bed of crushed aggregate or washed sand to cushion pipes against ground movement.
- Sub-Slab Vapor Barrier Restoration: Exposed 10-mil or 15-mil sub-slab vapor retarders are overlapped by 6 inches and sealed with specialized vapor tape.
- Concrete Pad Restoration: We pour high-strength concrete mix over backfilled trenches, finishing the surface perfectly flush with the adjacent slab floor.
Drain-Waste-Vent Pipe Sizing and Gravity Sloping
Underground Drain-Waste-Vent systems require properly sized Schedule 40 ABS or PVC piping installed at continuous downward gravity slopes. We size each branch line based on total drainage fixture units to prevent solids accumulation and sewer gas backups. Comprehensive roof venting maintains balanced atmospheric pressure across all traps, preventing siphonage during peak residential usage.
Underground DWV networks must utilize Schedule 40 piping manufactured in full compliance with criteria established by the International Association of Plumbing and Mechanical Officials. Proper pipe sizing ensures waste streams move smoothly without forming blockages over time. We calculate pipe dimensions and vertical vent terminal routes during the initial design phase.
- Toilet Drain Lines: Require a minimum 3-inch pipe diameter to handle high-solids waste streams effectively.
- Branch Lines (Kitchens, Showers, Laundry): Require 2-inch piping to transport high-volume grease, soap suds, and liquid waste.
- Lavatory Sink Drains: Require 1.5-inch or 2-inch piping tied directly into vertical vent stacks.
- Continuous Slope Requirements: Horizontal drainage piping 2 inches or smaller must maintain a continuous downward slope of 1/4 inch per foot, while pipes 4 inches or larger require 1/8 inch per foot.
- Venting Architecture: Every fixture trap must connect to a vent stack extending through the roof or re-venting into a main dry vent stack to maintain atmospheric equilibrium.
Water Supply Line Sizing, Metering, and Pressure Regulation
Delivering reliable potable water to a converted garage involves running dedicated copper or PEX-a supply branches from the primary service connection. We calculate volume demand and evaluate local street pressure to select optimal pipe diameters and pressure-regulating devices. This engineering approach guarantees consistent flow rates across all interior fixtures simultaneously without subjecting piping to high-pressure stress.
Potable water networks servicing converted structures must meet rigorous safety and hydraulic standards. Inadequate supply sizing causes dramatic pressure drops when multiple fixtures operate at once, leading to user dissatisfaction and accelerated pipe wear. Our technicians engineer custom supply piping routes that balance static pressure and volumetric flow.
Water Main Connection and Submetering Options
Connecting a garage conversion to municipal potable water can be configured through a shared main line submeter or a separate dedicated utility meter. We evaluate municipal water utility rules and client financial preferences to recommend the most efficient service configuration. Installing digital submeters provides clear tenant billing tracking without incurring unnecessary municipal utility connection fees.
Water service for San Fernando Valley conversions can be arranged through two distinct service models:
- Shared Master Meter with Submeter: The conversion connects downstream of the main property water meter, where a digital submeter tracks conversion usage independently for tenant billing.
- Dedicated Municipal Water Service: A separate utility meter is requested from the city, requiring street trenching, connection fees, and an approved exterior meter box installation.
Water supply runs must utilize Type L rigid copper or PEX-a cross-linked polyethylene tubing for long-term durability. We size the main supply branch feeding the conversion at 3/4-inch or 1-inch diameter to preserve volume when multiple fixtures function concurrently. This sizing approach ensures robust flow throughout the unit.
San Fernando Valley Water Pressure Management
Static water pressure across Canoga Park frequently ranges between 75 PSI and 95 PSI due to municipal distribution pumping systems. We install pressure-regulating valves and thermal expansion tanks to reduce incoming pressure to safe residential levels. Managing dynamic pressure prevents water hammer damage, protects delicate fixture cartridges, and satisfies regional plumbing codes.
Excessive municipal water pressure places severe stress on internal valve stems, flex lines, and appliance solenoids. The California Plumbing Code mandates installing a master pressure-regulating valve whenever incoming pressure exceeds 80 PSI. We calibrate these valves to establish a steady indoor working pressure between 50 and 60 PSI.
Creating a closed-loop system with a pressure regulator requires installing a thermal expansion tank on the cold water line feeding the water heater. As water heats, thermal expansion creates pressure surges inside closed pipe networks. The expansion tank safely absorbs these volume spikes, preventing dangerous pressure buildup and protecting system integrity.
Sewer Line Tie-Ins and Waste Management Systems
Connecting a garage conversion drainage system to the main sewer lateral depends on structural elevation, ground slope, and lateral distance. We analyze property topometrics to implement either direct gravity flow connections or heavy-duty sewage ejector pump systems. Strategic installation of exterior cleanout access points guarantees long-term drain line maintainability and code compliance.
The tie-in point where conversion waste enters the primary building sewer represents a critical structural transition. Miscalculating fall slopes or selecting incorrect fitting combinations leads to chronic waste accumulation and recurring main line stoppages. We conduct pre-construction sewer camera inspections to confirm line depth and structural integrity.
Gravity Flow Connection vs. Sewage Ejector Systems
Gravity flow drainage offers the most simple waste disposal path when existing sewer laterals sit lower than the garage slab. When structural elevations prevent natural gravity fall, we install submersible sewage ejector pump systems within recessed basins. This dual-approach capacity allows us to solve severe elevation constraints without altering primary foundation structures.
Selecting between gravity flow and pumped waste conveyance involves evaluating exact site elevations and structural fall requirements:
- Gravity Flow Connection: When garage slab elevation exceeds the main 4-inch sewer lateral elevation, waste flows naturally using directional wye fittings and long-turn sweep elbows.
- Sewage Ejector Systems: When garage floors sit below the sewer lateral or lack 1/4-inch per foot slope, a submersible sewage ejector unit is installed inside a sealed basin.
- Pump Operation: Heavy-duty grinder pumps force liquid and solid waste upward through a 2-inch pressure discharge line equipped with full-way check valves and ball isolation valves into the gravity sewer.
Mandatory Cleanout Access Points
Municipal plumbing standards enforce mandatory cleanout access points along private drainage networks to enable ongoing sewer maintenance. We strategically place exterior directional cleanouts near foundation walls, long pipe runs, and major directional fittings. Accessible cleanouts ensure rapid hydro-jetting and snake clearing without disrupting interior conversion living spaces.
Local building codes dictate specific cleanout placement to ensure complete drainage network accessibility:
- Building Drain Cleanout: Positioned outside the garage foundation within 2 feet of the exterior structure wall.
- Directional and Run Cleanouts: Required every 100 feet on long straight pipe runs and at any directional change exceeding 135 aggregate degrees.
- Property Line Cleanout: Located near the property perimeter where the private building sewer transitions toward the municipal main or alley easement.
Field Challenges and Technical Case Studies
Executing complex garage plumbing conversions presents unique structural obstacles, ranging from thick foundation grade beams to decaying historic sewer laterals. We leverage advanced trenchless technologies and specialized pumping solutions to overcome severe field challenges safely. Our detailed case studies highlight real-world field engineering strategies that resolved critical job-site issues efficiently.
In our decades managing residential conversion projects across the San Fernando Valley, we have resolved complex structural and hydraulic barriers. Encountering unexpected job-site conditions demands immediate technical adaptation and close coordination with city plan examiners. Below are two representative field projects detailing how our engineering teams resolved critical plumbing challenges.
Case Study 1: Resolving a Footing Grade Beam Obstacle via Ejector Integration
Encountering an unexpected 18-inch thick concrete grade beam during a garage conversion threatened to compromise building structural stability. We resolved this obstacle by engineering an above-grade branch piping system connected to a commercial sewage ejector pump pit. This custom layout bypassed the footing entirely, passed municipal inspection, and preserved full structural pad integrity.
During a conversion project on Roscoe Boulevard in Canoga Park, our trenching team discovered an unreinforced concrete slab containing an unexpected interior grade beam bisecting the floor plan. Traditional sawcutting through this heavy structural beam would have destabilized the perimeter foundation and triggered expensive structural re-engineering. We immediately halted excavation to formulate a non-destructive alternative.
Our engineering team redesigned the Drain-Waste-Vent strategy by elevating interior branch lines within raised subfloor framing to avoid trenching through the grade beam. We installed a heavy-duty Liberty Pumps sewage ejector unit inside a recessed pit located along the exterior perimeter wall. The ejector pump lifted effluent vertically through a 2-inch pressure discharge line overhead, completely bypassing the concrete beam before tying into the exterior sewer lateral. Municipal plan examiners reviewed and approved our revised isometric schematics without causing construction delays.
Case Study 2: Upgrading a Collapsed Clay Sewer Lateral via Trenchless Pipe Bursting
A collapsed 1950s vitrified clay sewer lateral beneath a newly paved concrete driveway threatened project budget and schedule viability. We utilized trenchless pipe bursting technology to pull a seamless high-density polyethylene pipe through the ruined clay lateral. This non-invasive method restored full hydraulic capacity, eliminated root intrusion, and saved significant hardscape restoration expenses.
On a project along Sherman Way, pre-construction video camera inspection revealed severe root intrusion, offset joints, and structural fracturing along a 65-foot clay sewer lateral. Connecting 13 additional Drainage Fixture Units from the new garage conversion to this compromised line would have caused frequent backups and violated city hydraulic capacity standards. Traditional open-trench excavation across the concrete driveway would have added 9,500 US Dollars in hardscape replacement costs.
Our team executed a trenchless pipe bursting replacement to preserve the existing hardscape driveway. We excavated two localized launch pits at the house exit and property line, then pulled a heavy hydraulic breaker head through the old clay pipe. The breaker head shattered the damaged clay pipe outward while simultaneously pulling a seamless 4-inch High-Density Polyethylene pipe into place. This trenchless installation expanded total hydraulic capacity, eliminated root intrusion points, and saved the property owner substantial hardscape repair expenses.
Technical Specifications and Code Comparison
Evaluating precise engineering parameters ensures garage conversion plumbing systems comply fully with regional building codes and environmental standards. We maintain detailed technical matrices outlining minimum pipe dimensions, mandatory slope requirements, and fixture unit load values. These baseline references assist engineering teams, contractors, and city inspectors during field validation phases.
Standardizing plumbing components guarantees reliable performance and prevents costly code non-compliance rejections during inspections. Below are three detailed technical tables summarizing code specifications, construction phase requirements, and fixture load allowances for residential conversions.
Technical Plumbing Specifications and Code Standards
Understanding exact pipe sizing, operating pressure ranges, and California Green Building efficiency limits is essential for flawless plumbing execution. We construct every sub-assembly in strict accordance with California Plumbing Code standards and local building department amendments. The table below details core technical specifications governing residential garage conversions in Canoga Park.
| Plumbing Component | Minimum Pipe Size | Required Slope / Pressure | CALGreen / CPC Efficiency Limit | LADBS Code Reference |
|---|---|---|---|---|
| Main Sewer Exit | 3-Inch or 4-Inch | 1/4 inch per foot (3-inch pipe) | N/A | CPC Chapter 7 / LADBS |
| Water Closet (Toilet) | 3-Inch Drain / 0.5-Inch Supply | 1/4 inch per foot slope | Max 1.28 Gallons Per Flush | CALGreen Title 24 |
| Shower Enclosure | 2-Inch Drain / 0.5-Inch Supply | 1/4 inch per foot slope | Max 1.8 GPM at 80 PSI | CPC Chapter 4 |
| Kitchen Sink & Disposal | 2-Inch Drain / 0.5-Inch Supply | 1/4 inch per foot slope | Max 1.5 GPM at 60 PSI | CPC Chapter 4 / LADBS |
| Lavatory (Bathroom Sink) | 1.5-Inch Drain / 0.5-Inch Supply | 1/4 inch per foot slope | Max 1.2 GPM at 60 PSI | CPC Chapter 4 |
| Main Water Supply Line | 3/4-Inch or 1-Inch | 50–60 PSI Working Pressure | Lead-Free Brass/Copper/PEX | CPC Chapter 6 |
| Natural Gas Main Run | 3/4-Inch or 1-Inch | 0.5 PSI Working Pressure | CSST / Schedule 40 Black Iron | CPC Chapter 12 / LADBS |
Rough-In vs. Finish Plumbing Phase Matrix
Dividing plumbing installation into sub-slab, top-out, and finish phases ensures systematic quality control and organized inspection sign-offs. We enforce strict material verification and pressure testing protocols at each construction stage prior to advancing. The matrix below outlines tasks, materials, and mandatory inspections across all project phases.
| Phase | Core Tasks & Components Installed | Material Standards | Required Testing & Inspection |
|---|---|---|---|
| Sub-Slab Rough-In | Trenching, underground DWV lines, toilet flanges, shower drains, trap arms. | Schedule 40 ABS / PVC, sand bedding. | 10-foot head water column or 5 PSI air test; LADBS underground inspection. |
| Top-out Rough-In | Wall supply lines, vent stacks through roof, gas line drops, water heater rough-in. | Type L Copper, PEX-a, CSST gas piping. | 50 PSI gas pressure test; 80 PSI water pressure test; LADBS frame/rough plumbing sign-off. |
| Finish Plumbing | Setting toilets, faucets, shower valves, water heater, garbage disposal, trim plates. | USA-manufactured brass, stainless steel, vitreous china. | Flow rate checks, leak checks, fixture operational test; LADBS final approval & C of O. |
DFU Load Values and Piping Sizing Matrix for Residential ADUs
Calculating Drainage Fixture Unit values determines required pipe diameters and prevents hydraulic overloading within residential sewer networks. We assign specific fixture unit ratings to every kitchen, bathroom, and laundry fixture during plan creation. The following table illustrates standard fixture unit values and minimum drain-vent sizing parameters.
| Fixture Description | Drainage Fixture Unit (DFU) Value | Minimum Drain Trap Size | Minimum Vent Pipe Size |
|---|---|---|---|
| High-Efficiency Toilet (1.28 GPF) | 3.0 DFUs | 3-Inch | 1.5-Inch |
| Kitchen Sink (including Garbage Disposal) | 2.0 DFUs | 2-Inch | 1.5-Inch |
| Residential Clothes Washer | 2.0 DFUs | 2-Inch | 1.5-Inch |
| Shower Stall | 2.0 DFUs | 2-Inch | 1.5-Inch |
| Lavatory Sink (Single) | 1.0 DFU | 1.5-Inch | 1.25-Inch |
| Dishwasher | 1.0 DFU | 1.5-Inch | 1.25-Inch |
Water Heating and Gas Pipe Installation
Selecting water heating systems and installing natural gas lines requires balancing Title 24 energy efficiency mandates with structural spatial limits. We install high-efficiency gas tankless units or electric heat pump water heaters to deliver continuous hot water reliably. Integrating automatic seismic gas shut-off valves protects converted structures from fire hazards during earthquake events.
Domestic water heating accounts for a major share of residential energy usage in converted living spaces. Selecting the right water heater depends on available electrical capacity, gas line proximity, and physical mounting footprints. Our technical team evaluates energy models during plan check to optimize utility efficiency and minimize operational costs.
Energy-Efficient Water Heater Options
Homeowners can select between compact exterior gas tankless water heaters and energy-efficient interior electric heat pump systems. We install both water heating technologies in full alignment with energy compliance software calculations. Evaluating fuel availability, electrical subpanel capacity, and mechanical space determines the ideal hot water system for each conversion.
We offer two highly efficient water heating solutions for conversion projects:
- Tankless Gas Water Heaters: Wall-mounted condensing units deliver continuous hot water while conserving interior floor space, requiring double-wall direct venting through walls or roofs.
- Electric Heat Pump Water Heaters: Hybrid electric heat pump units extract heat from surrounding air, simplifying Title 24 compliance and eliminating gas line requirements.
- Electrical Specs: Heat pump units require a dedicated 240V circuit, a 30-amp breaker, and a condensate drain line.
Gas Line Sizing and Seismic Safety Shut-Off Valves
Extending natural gas service to a garage conversion requires precise pipe sizing and mandatory seismic safety valve installations. We size fuel gas lines based on aggregate BTU loads using heavy black iron or corrugated stainless steel tubing. Installing earthquake-actuated shut-off valves at the main utility meter safeguards property occupants during seismic activity.
When gas appliances such as cooktops, space heaters, or tankless water heaters are integrated into the conversion layout, gas branch piping must extend from the main gas meter assembly. We calculate total BTU demand across all connected gas appliances to select adequate pipe diameters.
Municipal building regulations require installing an earthquake-actuated automatic gas shut-off valve on the discharge side of the primary gas meter. These mechanical valves automatically trip and stop gas flow during seismic movement of magnitude 5.4 or greater. Installing seismic valves prevents post-earthquake fires and protects the living structure.
USA-Manufactured Fixtures and Equipment
Specifying high-grade, USA-manufactured fixtures and commercial equipment guarantees exceptional durability, lead-free compliance, and long-term operating reliability. We partner with leading domestic manufacturers to source toilets, faucets, water heaters, and heavy-duty solids pumps. Utilizing top-tier equipment minimizes ongoing maintenance calls, protects property value, and ensures smooth final plumbing sign-offs.
Selecting commercial-grade plumbing components protects property owners against premature component failure and costly water leak damage. Cheap imported valves and low-grade fixtures frequently fail under high static municipal pressure. We exclusively install field-tested products from reputable American manufacturers.
- Plumbing Fixtures & Faucets: High-efficiency vitreous china toilets, cast iron or heavy acrylic bathtubs, and solid brass faucets from brands like Kohler, Moen, and American Standard deliver durable finishes and reliable flow controls.
- Water Heating Equipment: Commercial and residential water heaters manufactured by Rheem and Bradford White offer superior thermal efficiency and extended service life.
- Waste Disposals & Pumps: Heavy-duty food waste disposers built by InSinkErator and rugged sewage ejector pump systems manufactured by Liberty Pumps or Zoeller ensure dependable solids management.
Frequently Asked Questions
Addressing core technical and financial questions helps property owners make informed decisions regarding garage plumbing conversions. We provide direct answers regarding conversion installation pricing, utility submetering, sub-slab trenching, municipal permitting, and main sewer lateral connections. Our concise answers summarize key operational requirements for homeowners across the San Fernando Valley.
How much does plumbing installation cost for a garage conversion in Canoga Park?
Plumbing installation costs for a garage conversion typically range between 8,000 US Dollars and 18,000 US Dollars depending on overall project complexity. Core pricing factors include total linear feet of sub-slab concrete trenching, distance to the main sewer tie-in, whether a sewage ejector pump is needed, and the selected water heating technology. Total conversion costs across the San Fernando Valley average 68,000 US Dollars to 221,000 US Dollars depending on structural scope.
Do I need a separate water meter from LADWP for a garage conversion ADU?
No, municipal utility rules do not require a separate water meter for a residential garage conversion unit. Homeowners typically connect the conversion directly into the main home’s existing water supply downstream of the primary utility meter. Installing a digital private submeter on the conversion branch allows property owners to track utility consumption and bill tenants independently without paying city utility connection fees.
How do plumbers install drainage pipes beneath an existing garage concrete floor?
Plumbers cut structural channels through existing concrete floors using diamond-blade walk-behind saws along designated drainage runs. Soil is excavated to depths between 12 and 24 inches to lay Schedule 40 ABS drain pipe on a 4-inch aggregate bed maintaining a 1/4-inch per foot slope. Technicians repair the vapor barrier and pour fresh high-strength concrete flush with the existing floor pad.
What are the LADBS plumbing permit requirements for an ADU conversion in Canoga Park?
Plan review submittals must include architectural floor plans, fixture layouts, DWV isometric schematics, gas pipe sizing calculations, and CALGreen compliance schedules. Permits must be secured prior to cutting slab concrete or framing interior walls, followed by required field inspections for underground rough-in, wall top-out framing, and final fixture connections.
Can an ADU share the main house’s existing sewer line in Los Angeles County?
Yes, California state law and local building codes allow a converted unit to share the primary home’s existing sewer lateral. The main sewer line must be in sound structural condition—verified through video sewer camera inspection—and possess adequate pipe diameter (typically 4 inches minimum) to support the combined Drainage Fixture Unit load of both living units.
Sources
- Los Angeles Department of Building and Safety (LADBS): https://dbs.lacity.gov/
- International Association of Plumbing and Mechanical Officials (IAPMO) – California Plumbing Code: https://www.iapmo.org/
