Hill Country living is a dream for many. The mild winters and summer recreation make it the optimal choice for both raising a family or enjoying retirement. One of the questions our clients frequently ask during the design phase is how the placement of their new home impacts its energy efficiency and overall ambiance. We love this question because a house that’s optimized for day lighting helps its owners see better, think with more clarity, be safer, save energy, and have an overall enjoyable lifestyle.
Good day lighting is a balancing act. During the winter, sunlight that streams through your windows adds free solar heat that lowers your heating bill. And during summer, you want to prevent direct sunlight from overheating interiors. So, it is important for homeowners to understand good day light and its interaction with the following factors:
HOME ORIENTATION AND DESIGN
The best way to control day lighting is to simply have your house positioned correctly to the sun. Ideally, the largest facade of your house will face south and have the most windows.
If that does not work in your location, we have a few tips for you.
North-facing windows don’t receive much direct sunshine. Light from the north is usually soft, pleasing, and free of glare, which provides the ideal ambient light. However, during winter months, homes with large north facing windows can easily lose heat.
East- and west-facing windows receive lots of direct sunlight and can be difficult to shade. East morning light is usually acceptable, even in summer, as it chases off darkness and adds cheery sunshine to interiors during the early part of the day. But, western light is more difficult to manage. The hill country sun is strong, thus it is vital to reduce the number and size of western facing windows for an energy efficient home. A great way to accomplish this is to place the garage on the western side of your home.
For those whose new home has an amazing western view, a good compromise is to spend a little more for energy-efficient windows with low-E coatings. They cost about 10% more than regular insulated windows, but they should pay for the difference in energy savings in two to six years. Additionally, foam insulation is superior for heat/cold reduction permeating into the home.
Naturally, you will want to stop hot summer heat from entering your house. Shades and blinds can block harsh sunlight; but keep in mind they won’t prevent heat unless they are designed to save energy. For example:
Venetian Blinds are great at controlling light. By tilting them upward, you can direct incoming sunlight toward the ceiling, turning it into the ambient light.
Traditional Curtains and shades are the ultimate low-tech lighting control. Translucent shades and sheer curtains block direct sunlight, turning it into the softer ambient light.
If you want to prevent sunlight from entering your home on the outside, overhangs or eaves are a good option. The Texas sun is high during the summer, and roof eaves keep most direct sunlight out of south-facing windows. During winter, the sun moves low across the southern horizon, sending warming sunlight under eaves and into south-facing windows. The ideal length for an eave in this area is 1 ½ - 2-ft.
It is important to consider how much light each room in the home requires. Optimal lighting needs are impacted by personal preference and age. The lighting industry has developed several ways to measure lighting needs. One way is with footcandles (fc), which is the amount of light that falls on one square foot. Typically, on a sunny day, the area outside a home gets about 10,000 footcandles and on a cloudy day, about 1,000.
A fraction of that light enters a home as ambient daylight (from 1% to 10%) which is enough to meet typical household needs. Here’s a quick guide:
Living room: 10-20 fc
Kitchen, general: 30-40 fc
Kitchen stove: 70-80 fc
Dining room: 30-40 fc
Hallway: 5-10 fc
Bathroom: 70-80 fc
If you are still interested in learning more about optimizing natural light during the design process contact TriBuilt today.