The ADU is wrapped with thick exterior insulation—a PERSIST envelope, which offers unmatched performance in thermal, air, moisture, fire, and pest resistance.
PERSIST is: Pressure Equalized Rain Screen Insulated Structure Technique. A robust continuously-adhered weather barrier air seals the sheathing. The structure and weather barrier are then thermally protected by thick insulation with minimal thermal bridges. Wood siding is fastened to strapping to allow the walls to breathe to the exterior as a 'rain screen.'
This is the perfect wall.
The thermal performance of this envelope allows the ADU to easily offset its carbon footprint over time and to operate as a zero-energy structure with active solar energy harvesting.
High-performance windows set into a Tight Frame structure allow generous glazing and natural cross-ventilation, while avoiding compromise in envelope performance.
How does thermal performance stack up to the 2018 WSEC?
· Roof (U 0.016): 1.6 times better
· Walls (U 0.028): 2.0 times better
· Slab (F 0.300): 1.8 times better
With a modeled EUI of 10.6 kBtu/sf/year, the ADU is 4.2 times better than the national average.
Energy modeling and cradle-to-cradle life-cycle analysis help us meet aggressive sustainability targets: Zero Energy (ILFI), Zero Carbon (ILFI), Zero Energy Ready Home (DOE), Indoor AirPlus (EPA), and others.
The ADU features passive solar strategies, utilizing abundant winter solar heating from south-facing glazing. An 8:12 roof pitch is ideal solar exposure, yielding an expected 3,544 kWh / year in Seattle, WA.
We expect a PERSIST home to last 200+ years.