Fenestration - Week 2
Experiential and Environmental Impacts
Openings (or lack thereof) in the building envelope have the potential to make or break a design. One of the biggest mistakes you can make is to wait to design the openings at the end of the project. While openings should be informed by the building’s form, there are also a number of experiential and environmental factors that should ideally be in some stage of consideration even at the beginning of the project.
Experiential Factors
(Natural) Light As an artist, one of the most important factors of whether I like a space or not is the level of natural light. I find natural light to be less harsh on my eyes than artificial, so I always try to find work spaces that are near windows. One of my favorite examples of a well-naturally-lit space is Renzo Piano’s UNESCO Workshop in Genoa, Italy. Almost the entire roof consists of skylights, but the space doesn’t feel overly-bright. It feels like a calm yet energetic space to work in. For me, this would be the epitome of a productive space.
On the flip side, there are spaces that require a more controlled use of natural light. Libraries, for instance, may have spaces with natural light pouring in, but can’t have direct natural light on the books. The same is true for museums - direct sunlight = fading and UV damage, which is the last thing you want in spaces dedicated to preserving art and artifacts. In these cases, there are two common approaches: either natural light is forgone in favor of artificial lighting, or openings are used to control and introduce light in a way that won’t damage occupying objects, often by diffusing or redirecting rays so they don’t hit objects directly.
(Want to read more on openings and lighting? Watch for a link to another post in the coming weeks)
Ventilation and Fresh Air Another important factor to consider is whether or not to use operable openings - that is, openings that actually open and close, as opposed to stationary, fixed-in-place openings. Again, this will depend on use of space - are you designing a meeting room, or an art gallery? The latter will most likely require both temperature and humidity control, so if openings are present, you would want to go with the non-operable option. In any space that doesn’t have specific temperature or humidity needs, the choice of operable or non-operable is a little more open. There are benefits and drawbacks to either option.
Operable windows are going to let in more air, even if they’re not open. In colder climates, this can a big drawback. Those in the northern US know that even the tiniest crack in a window’s seal can bring a room’s temperature down by five to ten degrees (Fahrenheit) easily in the winter. However, they can be extremely beneficial in the more temperate months - when it’s too cool to turn on the AC, but too warm for heat, and the whole house becomes stuffy if nothing’s running.
Fresh air is also generally better for you than air that’s been pumped through a mechanical system, where the same air and everything in it, from germs to dust, is being recirculated through the space multiple times. It’s also been shown to be tied to improved health and productivity in workplaces. Unless you’re in an area with heavy pollution, opening a window can do wonders for freshening up a space.
Non-operable windows are generally more preferable aesthetic-wise. In areas where bugs are an issue (read: everywhere), screens are often used to keep those bugs out. Aesthetically speaking, a mesh screen blocking views and interrupting the seamless look of that beautiful tall office or apartment building aren’t viewed favorably. Sure, you could forgo the screen, but do you really want to deal with wasps flying in through your bedroom/classroom/office window?
Environmental Factors
The environmental aspect is going to come down to whether or not you want to employ passive design strategies - that is, design strategies that work with nature to regulate the interior environment of a building. These sorts of systems require less man-made energy than active systems like HVAC, and leave a smaller carbon footprint. In passive design, openings are used as primary sources of light, ventilation, and temperature regulation.
Well designed windows and shading devices can bring in necessary warmth in the winter, and keep it out in the summer. Combined with other design elements, one or two properly placed windows can easily regulate the temperature in a small single-family home. Similarly, a combination of openings, shades, and light shelves can comfortably light a space without being overbearingly bright.
Placement and size of openings also determines how air will flow throughout the space - if your only two openings are on the same wall air flow will be limited, but placed on opposite or adjacent walls they can create cross flow to keep entire spaces cool and well-ventilated.
While importance of one factor or another might change from project to project, the level of consideration shouldn’t. The decision to exclude openings from a space should be just as well researched and thought out as the decision to include a 30′ wide operable skylight. Consider the use and users of your spaces and get an idea of the need for openings early on, and keep those considerations at the forefront of your mind as you design.












