San Diego sits at 32.7° latitude. The summer-solstice sun climbs to 80.7° above the horizon at solar noon — almost straight overhead. The winter-solstice sun peaks at 33.8°, low and long from the south. That 47-degree swing is the single most important number in California passive design, because one south-facing overhang can shade summer sun completely and admit winter sun completely — for free, forever, with no moving parts.
The strategies that carry the load
| Strategy | Cost premium | Where the savings show up |
|---|---|---|
| Right orientation on the lot | $0 (design decision) | 20–40% lower annual cooling load |
| South-facing overhangs sized for the sun | $1–3 / sf of overhang | 60–80% less summer heat gain through shaded glass |
| Light shelves and clerestories | $2–5 / sf of window | Daylight 40–70% of daylight hours |
| Cross-ventilation geometry | $0 (design decision) | Eliminates most AC use in San Diego |
| Polished concrete floors as thermal mass | $3–8 / sf vs finish flooring | 5–8° cooler afternoons; night flushing |
| MWELO-compliant drip landscape | 15–20% over spec landscape | 40–60% lower water bills |
| Rainwater capture + laundry-to-landscape | $2,000–$8,000 | Landscape water offset in wet years |
Daylight without glare
Light shelves — horizontal reflectors placed above eye level at south windows — bounce daylight off the ceiling and push it two to two-and-a-half times the ceiling height into the room. In a room with a 10-foot ceiling, that is 20–25 feet of usable, glare-free daylight. Clerestory windows placed high on south walls admit even, diffused overhead light without the glare of a big picture window at eye level. Vertical fins in front of east and west glass, angled to the sun path, handle the low-angle morning and afternoon sun that horizontal overhangs cannot reach.
Cross-ventilation and stack effect
San Diego gets a reliable sea breeze from the west-northwest mid-morning through late afternoon and a 20+°F diurnal swing between afternoon high and pre-dawn low. Cross-ventilation — operable openings on opposite walls of the same room, low on the windward side and high on the leeward side — flushes the interior with cool ocean air during the day. Stack ventilation — a tall central room with a high window that opens — pulls warm air up and out overnight and lets the thermal mass reset for the next day. In a well-designed San Diego home, ceiling fans replace air conditioning for most of the year.
Water-smart site planning
California's Model Water Efficient Landscape Ordinance (MWELO) sets a maximum Estimated Total Water Use for the landscape based on hydrozones — plants grouped by water need. Drip irrigation replaces spray heads. Native and Mediterranean plants replace turf. Graywater from laundry and rainwater from roofs offsets potable water in wet years. Building shadow — the north face of the house, or the west side under a projecting overhang — is a real landscape asset: it stays cool in summer, holds moisture, and supports plants that would burn in full sun.
Related: renovation and addition guide, ADU permit reality check, and land and passive services.
Questions we hear
What is passive design and does it actually work in San Diego?
Passive design shapes buildings so orientation, shading, ventilation, thermal mass, and daylighting do most of the comfort work before mechanical heating and cooling are considered. San Diego's climate is one of the best in the country for it: a 47-degree sun-angle swing between summer and winter solstice, reliable west-northwest sea breeze, and a 20+°F day-night temperature swing that lets thermal mass work at night. A well-oriented San Diego home with sized overhangs, cross-ventilation, and shaded west glass can eliminate most active cooling for 8–10 months a year.
How much more does passive design cost to build?
When passive strategies are designed in from schematic design, the construction premium is typically 2–5% — mostly overhangs, light shelves, better window specs, and thermal mass floor finishes. Operating energy use typically drops 30–60% over the life of the building. On a $1M budget that is $20,000–$50,000 spent once to save $2,000–$4,000 every year in utility bills, before rebates or Title 24 outperformance credit. The cheapest passive strategies — orientation, opening placement, room arrangement — add zero cost when decided at first-plan stage.
What passive strategies actually matter for a California home?
The strategies that carry the load are: orienting the main living rooms and glass south, sizing south overhangs to 40–50% of window height so summer sun is blocked and winter sun is admitted, minimizing or vertical-finning west glass, pairing operable openings for cross-ventilation, adding a tall room for stack ventilation, placing thermal mass where south sun can hit it, and using light shelves under high south windows to push daylight 2–2.5 times the ceiling height into the room. On the site side, MWELO-compliant drip landscape, hydrozoning, and building shadow as landscape asset are the highest-leverage moves.
NALU® is a registered trademark of Nalu Architecture, Inc. Architectural services are provided through Chris Schumm, AIA, California Registered Architect, License No. C-36569. This page is general planning information for 2026, not an opinion on a specific site. Every engagement is scoped and contracted individually.