Homework #6 4.492 Daylighting November 5, 2004 Ed Rice The Carpenter Center for Visual Arts, Harvard University Analysis 4 th and 5 th Floor Studio Spaces The Carpenter center for Visual Arts was completed in 1961, and was designed by the architect Le Corbusier. The center provides a home for the Harvard University department of visual studies. Spaces within include studios, exhibit spaces, faculty and administrative offices, a café and various support spaces. The immediate context consists of 4-5 story university buildings and some trees. The two streets that bound the site run roughly North-South (fig1) and most building are rectangular in plan, and are aligned with the streets. Le Corbusier, chose to rotate his building roughly 30 degrees in plan (fig 2). Most of the space in the square floor plan is for exhibition purposes. The spaces within the curvilinear extensions are studio and office areas. Fig1-2. Site/Orientation Plan Fig 2a. Plans showing areas of study 1
5 th Floor Studio For the purposes of this study, I chose to analyze the studio space on the 5 th floor. This space is a smaller area than the typical floor layouts. This space could be described as a penthouse surrounded by the roofscape of the larger building below. Working at the top of the building, the architect had many options for using daylight at his disposal. (ie. toplighting, and sidelighting from (4) unobstructed exposures). For comparison purposes, I also looked at the studio space below on the 4 th floor (see fig 2a). The 5 th floor studio space receives daylight from exposures to the east, south, and west. On the east wall LC uses bearing walls canted in plan 30 degrees. This aligns the walls with the street relative to the building orientation shift and allows exposures to the northern daylight. Setbacks from the street (fig 2) help this cause by opening up patches of sky. This is more important for the lower floors. Daylight from the north direction only, is then allowed to enter the space indirectly. This strategy is consistent with the eastern and western facades of the square volume. Fig 3. Luxometer readings Fig 3a. Isometric view of space 2
Fig. 3b. Sections looking north. Fig. 4a Fig. 4. South shading overlay The space gets much more daylight and some direct sun from its southern exposure. This side of the space has both horizontal and vertical shade which, like the angled bearing walls on the north side, is integral to the structural stiffening of the building and is built of poured in place concrete (fig 3,a,b). LC had used this shade design extensively in hotter climates (ie Chandigargh, India). It is interesting to note that the lower sun angles experienced at our latitude allow some patches of sunlight between 10 and 2 PM during the winter months from October to March. (fig 4). On the west there is a fully glazed wall, getting lots of daylight throughout the day. A bit of direct sun is experienced in the summer months near dusk. In general, the space received more than enough daylight, readings ranged from 100-2700 lux during sunny sky conditions at 10 AM. The space was usable as an art studio without any artificial lighting for the majority of the day. 3
Throughout the building, monolithic glass panels (ie non-insulated), are directly glazed into reglets in the concrete, provide a high rate of heat conduction across building envelope in the heating season. It did seem that the concrete lintel was retaining some solar energy as heat. It remains to be seen whether this solar gain is significant enough to overcome heat loss through the concrete in the winter. I noticed that the studio was far more frequently used than other spaces. I also noticed that students who had set up work close to the southern exposure had chosen to remain facing the north wall. P Recommendations In my opinion, lots of daylight in this space makes it a favorite for students, as evidenced by higher degree of occupancy than other areas. Exposures on three sides add to the light levels and this aspect should be maintained when making changes to improve visual comfort. Indirect glare from the adjoining roof terrace and the secular surface of a skylight is a problem. The fulfillment of the original plan for planted roof garden would cut down on the glare from the roof surface (fig 5,6). In addition, a movable shade at the south side would allow the user to block the direct sun fully if needed. The daylight from the west window wall is welcome, but the large patch of sky exposed produced some glare for students should they choose to orient themselves to the north. A lintel, or light shelf placed high would still allow daylight but would cut into the view of the bright patch of sky (fig7). Similar high lintels are used elsewhere in the project (fig 8). In a visit to the building during the late evening, it became apparent the flexibility of having opening s on three sides of a space. As light levels drop in the east, the western exposure is able to maintain light levels in the 200-300 lux range, as observed at 4:00 PM. Fig 5. Roof seen from 5 th floor Studio Fig6. Planted roof terrace at 2 nd floor Fig 7a. View West 4
Fig 7b View west showing proposed lintel. Fig 9. 4 th Floor studio luxmeter readings Fig.8 High lintel on west façade. 4 th Floor Studios In contrast, the studio space on the 4 th floor had similar canted bearing walls to the east, which provided indirect daylight from the north. While this strategy reduced glare almost entirely, artificial lighting was required after only 5 meters when levels dropped below 100 lux. This finding suggests that the space might have been more useful as exhibition space, rather than the current usage as studio space. After reviewing the drawings, the space had been originally designed as exhibition. Most of the reflective surfaces had been painted darker colors, diminishing the amount of redirected light. (fig 9-10). Fig. 10 4 th Floor studio. 5
Recommendations and Conclusion: On the 5 th floor, the flexibility offered by multiple exposures seems to be much better for insuring higher light levels during the day and during different sky conditions. While the southern exposure posed a challenge, I would not suggest blocking these openings with permanent shades. Overcast conditions were not observed at the 5 th floor, but it seems that electric lighting would not be necessary. The space was observed to have nearly enough daylight at 4:00 PM due to the large western exposure (though some electric lights were turned on at the north). For spaces that are more continuously occupied, daylight from multiple sources makes sense. Though the light coming into the 4 th floor studio was well focused, the space was far to dark to be used without electric lighting. Overcast conditions would further exacerbate this. Suggestions include the installation of skylights, or the usage of this space for other as an exhibition gallery or library stacks. 6