CASK House

Modern interior with a wooden accent wall, staircase, and blue armchairs. A person walks up the stairs. A round wooden table and pouf are on a patterned rug beneath a contemporary chandelier.
Small house with wood and stucco exterior, surrounded by trees, featuring a front porch with a green chair and a bicycle.

Zero Net Energy, High Performance Home

TYPE: New Construction, High Performance, Net-Zero Energy.

SIZE: 1690 sf

LOCATION: Nevada City Area, Northern California

DATE: 2015

DESIGN: Mela Breen | Atmosphere Design Build

CONTRACTOR: Atmosphere Design Build

STRUCTURAL ENGINEER: Mark Jokerst, SE

MECHANICAL: Balance Point Home Performance

PUBLICATION: Dwell Magazine: Special Issue October, 2016

Photography: Kat Alves

Rustic house with wooden siding and metal roof surrounded by pine trees.

With an eye toward creating a sustainable future for a young family of four, the design for this home focuses on integrating ecological building strategies, energy efficiency, and an accessible open floor plan that is flexible enough to adapt to the family’s changing needs. The house is situated on a sunny south facing site, with glimpses through the native oaks of the local creek canyon below. The house opens to the south and sits close to grade minimizing the inside-outside transition. Covered terraces and porches provide the appropriate solar shading and expand the living area for the modest house during the many seasonable Northern California months.

Rustic wooden porch with corrugated metal roof, natural log support post, green Adirondack chair, potted plants, and surrounding greenery.

Combining a super-insulated, airtight, building envelope with optimized solar design to drive energy loads to very low levels and s simple form and massing allowed for a cost-effective high-performance building envelope. The has superior thermal comfort and excellent indoor air quality that creates a healthy indoor environment.

Modern kitchen with blue cabinetry, stainless steel appliances, wooden island, open shelves, large windows, and pendant lighting.

Inspired by natural building materials and raw industrial loft spaces, the owners wanted to create a home that both celebrates the “imperfect” qualities of handmade structures and that also has a clean contemporary feel. A weathering steel metal roof, native log post details, polish concrete floors, salvaged wood, and locally sourced materials and products are used to underscore the aesthetic and ecological goals.

Modern kitchen with blue cabinetry, concrete countertops, and stainless steel appliances. Open wooden shelves hold colorful dishes and a green kettle sits on the stove. A large window brings in natural light.
Interior with a sliding barn door made of reclaimed wood, leading to a bright room with a bookshelf filled with books and a globe. The hallway features modern pendant lighting and a plant near the window.
Wooden staircase with wire railing above a cozy nook with a blue patterned pillow and a fluffy beige throw.

“We are all responsible for so many sources of energy consumption in our daily lives that we were intrigued by the possibility of reducing the ecological footprint of our home. During our research, we found that some emerging “green” technologies still cost more to adopt early on yet there were also several approaches that were cost effective and energy efficient (making it hard to imagine why they aren’t standard practice). We were excited about building a passive solar house long before we knew where, when or how we would eventually make it happen. Letting the sun and shade take care of most of our heating and cooling during the appropriate seasons is such a simple and effective idea (and who doesn’t want a wall full of beautiful south facing windows?!). As a result of the passive solar design, plenty of insulation, and excellent air sealing (all simple strategies), the temperature of our house stays steady and comfortable year-round with very little energy input from a heat pump. We also chose to have everything in our house run on electricity so we could reach net-zero energy consumption with solar panels. Not paying any energy bills is nice but there is also a bigger sense of energy independence that feels very liberating. Regardless of the slow-moving politics or quickly accelerating climate change, we have removed ourselves from one piece of the problem.”

— Shanti Cavanaugh

Small rustic house at sunset with wide windows and natural wooden beams, surrounded by trees and gravel path.

High Performance Highlights

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Assembly

The structure was built using advanced framing techniques, thermal free bridge construction details and thoughtful structural engineering to minimize wood usage. The well insulated includes a The roof is R-80, walls are R-30 with continuous exterior insulation, and the slab is insulated and thermally broken. Triple pane fiberglass windows provide comfort and excellent air tightness.

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Climate Control

A balanced heat-recovery ventilation system (HRV) ensures constant fresh, filtered air, throughout the home without any substantial heat loss.

A single ductless mini-split is the primary heating and cooling source (with a second auxiliary mini-split added to the loft space to help with stratification).

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Energy

The all electric building has a 6.9 kW solar photovoltaic array that provides a renewable energy. Backup batteries provide resiliency for power outages and load shifting. Net-zero energy usage, under met-metering, includes car charging.