A House with Abundant Daylight

Sustainable House in South Texas by ArquiNature Studio

CREDITS
ArquiNature Studio
Conceptual Design: Liliana Beltran
Project Development: Gladys Lopez
Energy and Lighting Consultant: Beltran Daylighting Lab

Program: This single-story affordable house was designed to be adaptable as a home-office and to accommodate occupants with ADA requirements. The owners requested a sustainable, low-energy house that connects to nature. Multiple simulation tools were used throughout the design and project development to ensure an energy-efficient building with enhanced daylighting.

Design Solution:
The design addressed challenges posed by the small, trapezoidal infill lot and the hot, humid climate of Southern Texas. The existing live oak tree was integrated as a central element of the house design, serving as a focal point visible from all living spaces. The house features cathedral ceilings and a rectangular layout along the east-west axis, incorporating several bioclimatic strategies: daylighting, ventilation, shading, high insulation, minimized infiltration, a high-performance envelope, and light-colored materials with high albedo and low emittance. Casement windows (100% operable) in two directions maximize cross-ventilation in regularly occupied spaces.

Most windows are large (5’ x 4.5’) to provide ample daylight and unobstructed views of the outdoors. These triple-pane turn-and-tilt windows are Passive House certified, predominantly facing south with minimal openings to the north, east, and west. During the hottest months, the house is shaded by overhangs and the garage, while in winter, the south-facing windows allow sunlight and heat into the living spaces.

The living areas are connected to a detached west-facing garage by an east-facing covered veranda with a high blue wall that echoes the Texas sky. The house is strategically oriented to harness prevailing southern winds for natural ventilation throughout the living spaces, connecting areas, and garage during the hottest months. The veranda allows occupants to enjoy the morning sun, supporting circadian rhythm regulation and vitamin D production.

Sidelight windows, skylights, and clerestories provide abundant natural light throughout the day, minimizing the need for electric lighting until sunset or overcast days, which are rare in this region (less than 14% annually). Measured Equivalent Melanopic Lux (EML) across the living spaces exceeds 500 EML, surpassing the WELL Standard minimum of 275 EML for more than four hours under clear skies. Leveraging daylight has the potential to significantly enhance the overall health of building occupants.