Shade First: A Comfortable ADU Starts with the Sun
A compact home can feel generous when daylight is intentional. Before choosing the largest window or the darkest frame, look at where the sun reaches the property—and where you actually want to sit, cook and sleep.
For this Journal entry, we are focusing on design choices rather than new ADU legislation. The following ideas are a starting point for a property-specific discussion in California or Arizona.
Start with orientation
Draw a simple compass on your site sketch. Mark neighboring walls, trees, useful views and the windows that would face each direction. Then ask how the kitchen, bedroom and outdoor sitting area will feel at different times of day.
The U.S. Department of Energy’s passive-solar guide recommends north-facing windows and generously shaded south-facing windows in warmer climates. It also identifies overhangs, trees and awnings as ways to manage seasonal sunlight. Their dimensions and placement need to respond to the actual site, rather than a standard decorative detail. Read the DOE guide.
Our design suggestion: consider a shaded threshold between the living room and yard. A modest covered entry or protected sitting area can organize the transition outdoors without relying on a large wall of glass.
Compare performance, not just frame color
A dark bronze or black frame may suit the architecture, but its color does not tell you how the complete window performs. Ask for the product’s certified ratings:
U-factor: a lower value means less heat transfer through the window.
Solar heat gain coefficient (SHGC): a lower value means less solar heat passes through.
Visible transmittance (VT): a higher value means more visible light passes through.
These are different measures. Compare them together instead of treating more glass as an automatic improvement. ENERGY STAR explains the NFRC ratings.
ENERGY STAR’s window criteria vary by climate zone. Choose products for the project location; a window selected for one region is not automatically the best option for another. See the climate-based selection guidance.
Use a model as a conversation starter
Explore our California series for layout inspiration, or compare the forms in our Contemporary series. A courtyard, recessed entry or shaded opening is worth discussing in relation to your property’s orientation and neighboring spaces.
Try an illustrative footprint in the property planner and bring these three questions to your consultation:
Which rooms receive direct sun, and when?
Where would shade improve everyday use?
Which window ratings and shading details suit this location?
Our planner and visualizations are concept studies, not a survey, energy model or permit determination. Project-specific energy and local permitting requirements still need review. Paid plan downloads remain unavailable while payment and fulfillment are being finalized.
Discuss your project with our online studio. Follow @adu_design_studio for companion design notes.
