Set new standards now and build
a sustainable legacy for future generations.

Sol-Lux Alpha is San Francisco's first multi-unit Passive House and true Carbon Neutral Living and Transportation system. A Net Zero Energy (NZE) building produces as much energy as it uses, whereas a Net Positive (N+E) structure produces more energy than it uses, which can then be put toward charging electric vehicles on site or exported back to the local grid. In this development model, enough renewable energy is stored within the building for it to run without grid power for extended, even indefinite, periods of time.

Pioneering Nanogrid Features


Solar Photovoltaics (PV)

The building's power comes from an innovative raised trellis with 96 Bi-Facial BIPV solar modules from a local supplier, SunPreme. This 35.5 Kw array will produce up to 30% MORE power (up to 46 Kw) due to the “bi-facial effect” of having solar receptors on both the top and underside to utilize reflected and ambient light energy from the deck and surrounding city below. These modules also allow filtered light through so as to gently shade the luxurious deck, lounge, and outdoor kitchen spaces on the roof.

Storage and Management

Sony Lithium Iron Phosphate battery banks provide 104.5 Kwh of Energy Storage for the nanogrid building. This means that if the electric grid goes out, due to natural disasters or any other grid disruptions, the building will stay powered for all major systems, including 120V charging for Electric Vehicles. The Energy Storage System (ESS) and Energy Management System (EMS) are provided by project partners Blue Planet Energy of Hawaii. The Sony / BPE system carries a 10 year, 8000 cycle life warranty to 60% of original capacity. 8000 cycles is equal to almost 22 years, if the batteries are fully cycled once a day.


Advanced Passive House Construction

Virtually Air-tight Construction

Air infiltration is a major source of inefficiency in all types of buildings. The Passive-House system virtually eliminates infiltration-related heat loss with carefully sealed, and rigorously tested, exterior joints and penetrations. Of course, this creates a very water-impervious barrier, as well.

Ventilation, Cooling and Heating

Passive House buildings are continuously ventilated with fresh, filtered outside air through Energy Recovery Ventilators (ERVs). This device allows the clean heat, cooled air and controlled humidity to stay inside as the stale inside air is exchanged for fresh outside air.

High-Efficacy Lighting

Combined with an abundance of natural daylighting, the energy-efficient LED fixtures installed throughout the building reduce Sol-Lux Alpha's lighting electric energy consumption dramatically. Additional strategies, such as ultrasonic motion detectors to reduce ”vampire loads” in receptacles, have also been incorporated.

Luxurious Eco-friendly Materials

The FSC certified, non-formaldehyde, very low to zero VOC materials selected for construction finishes promote a healthy and safe indoor environment, durability and high-performance, as well as optimize the lifecycle of materials while requiring less maintenance. US EPA "Watersense" Certified plumbing fixtures and valves will be installed throughout.

Water Heating

Sanden CO2 Heat Pump Water heaters are approximately 35% more energy efficient than conventional “Heat pump water heaters” (HPWH). Conventional HPWH’s are already 2 to 3 times more efficient than conventional electric models, resulting in energy saving of over 70%. Sanden’s patented CO2 refrigerant technology has 1/1000 the global warming impact as refridgerant used in other HPWH’s.

Drought-tolerant Landscape

As San Francisco's pioneering multi-unit net positive structure, Sol-Lux Alpha also recognizes its responsibility to conserve California's precious supply of water. Drought-tolerant plants in the roof deck planters minimize required irrigation. The southwestern light well, off the kitchen and entry space, is designed to have wall to wall planting shelves for vertical vine plants and herb gardens.

Water Catchment System

The Raised PV Solar Trellis above the roof deck/garden space is also designed as a water catchment system. Water will be stored within “Rain Water Hog” catchment tanks integrated into planters on the roof. This water will be used to irrigate the vertical gardens in the light well, and also for an emergency water supply.

High-Performance Building Insulation

The windows and doors of a conventional home are usually the “biggest losers” of energy. Passive House windows and doors employ very strict limits on air infiltration and thermally-modeled insulative qualities. Further lowering heating and cooling energy costs, Sol-Lux Alpha incorporates High Density Blown-in-Blanket Insulation (BIBS), and other enhanced insulations, providing energy-modeled excellent thermal resistance — additionally reducing unwanted outside noise intrusion.


Exceptional Certifications

Sol-Lux Alpha is the first building in San Francisco to achieve an "alternate path of compliance" to SF's rigid Green Building Code. Using three certifying bodies, testing resulted in unmatched efficiencies for energy and water use, as well as utilizing the highest standards of sustainability.


The Passive House Institute US (Phius), maintains and certifies the highest standards for site energy efficiency in the world today.

Energy Star

The US Energy Star program guides builders and homeowners to the highest efficiency home appliance and other home energy products available in the USA today.

US EPA WaterSense

The US EPA WaterSense program helps save water and protects the environment by promoting WaterSense labeled products for homes, yards, and businesses, while taking various other simple steps to save water each day.

Department of Energy Zero Net Energy Home

The United States Department of Energy has developed a builder/partners program dedicated to the future of building science and energy generation for Zero Net Energy and Net Positive Energy homes in the USA. Klein Limited Partners, along with US DOE partners, Sarter Construction & Design and Off The Grid Design are proud to build Sol Lux Alpha far above even the DOE program's highest standards.

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