About ModernGrannyFlat — San Diego's ADU and Granny Flat Specialists
ModernGrannyFlat is a multi-disciplinary team based in San Diego that specializes in modern, eco-friendly, and affordable accessory dwelling units (ADUs) under California's evolving ADU laws. As a dedicated granny flat builder and ADU contractor, they collaborate with trusted architects, local contractors, and engineers to deliver thoughtfully designed secondary units that maximize space, property value, and livability.
Whether a homeowner is looking to supplement their income through rental, extend their living space, or house family members, ModernGrannyFlat offers a full-service approach — from initial design concepts through permitting, bidding, and construction monitoring.
What Is a Granny Flat or ADU in San Diego?
A granny flat — also known as a companion unit, in-law unit, backyard unit, or Accessory Dwelling Unit (ADU) — is a secondary housing unit on a single-family residential lot. As an experienced accessory dwelling unit builder, ModernGrannyFlat works across several ADU types, including:
- Detached new construction
- Units attached to the existing home
- Space above the existing house
- Interior conversions from existing space (attic or basement)
- Garage conversions
As a seasoned garage conversion contractor and detached ADU builder, they bring design expertise and regulatory knowledge to every project type. Their award-winning San Diego Garage Conversion — recognized at the American Institute of Architects Awards 2019 in the ADU category — is a prime example of their ability to transform an existing garage into a fully functional, flexible, and sustainable living space.
ADUs in San Diego are subject to specific regulations. Key considerations include a maximum size of 1,200 sq. ft., setback requirements that vary by zone, solar requirements for detached ADUs, and rules around owner occupancy and utility connections. Importantly, ADUs cannot be sold separately from the main home and may only be rented for periods of 30 consecutive days or more.
California ADU Laws and What They Mean for Homeowners
Since 2017, California has passed a series of bills that have made building an ADU significantly easier and more affordable. ModernGrannyFlat stays current with these changes to ensure every project benefits from the latest legal advantages. Key legislative updates include:
- Assembly Bill 881: Eliminates minimum lot size requirements, reduces maximum setbacks to 4 feet, allows ADUs on multifamily lots, removes the need to replace off-street parking, and eliminates owner-occupancy requirements.
- Assembly Bill 670: Prevents HOAs or CC&Rs from blocking ADU construction on single-family lots.
- Senate Bill 13: Prohibits impact fees on ADUs under 750 sq. ft. and removes replacement parking requirements for garage conversions.
- Assembly Bill 68: Allows up to three units — an ADU and a JADU (Junior ADU, max 500 sq. ft.) — on a single-family property lot.
As a knowledgeable JADU contractor and in-law suite builder, ModernGrannyFlat helps homeowners navigate these regulations strategically. For example, on one La Mesa project, they intentionally submitted permits the day after traffic fees were reduced by 50% and designed the unit at 749 sq. ft. to avoid impact fees entirely — resulting in significant savings for the client.
Their process is structured across three phases: Phase 1 covers design and permits, including understanding client needs, completing building permit sets, and submitting to the city. Phase 2 involves detailed contractor sets and competitive bidding. Phase 3 is construction, with ongoing contractor monitoring until the ADU is ready to occupy.
ModernGrannyFlat believes in architecture that works in harmony with nature — sustainable, flexible, and designed to adapt to the changing needs of its inhabitants over time. They are a trusted backyard cottage builder for San Diego homeowners looking to make the most of their property.
