Design Journal Entry - Module 4

1. Analyzing the Location: Jasper Ridge Biological Preserve

In the previous Modules, I had decided on the location of my site being around the Stanford campus. As I have moved here from London, the drier North Californian climate is something I appreciate, and would thus like to base the project in the local area. Additionally, Stanfords campus being full of eager students, makes it an ideal location for an exhibition space.

The key factors to deciding the location, were based around the climate (which will be discussed in detail below) and the proximity to campus. The later was an important consideration, as access to sustainable transport was a key goal I had outlined in Module 3. While the Stanford Dish area provided a location closer the heart of campus, and therefore accessible by bike, it also had some trade-offs. The steep incline of the hill, meant that it was unlikely students would cycle there during visits despite its proximity. Additionally, the barren landscape did not fit in well with the exhibition space’s topic of sustainability, and my design theme of integration into nature. As I had outlined in Modules 2 and 3, I intend on utlizing green-spaces as part of the building design, which the Biological Preserve of Jasper Ridge allows. The surrounding Searsville Lake, and diverse fauna & flora that accompany it, make for an ideal environment to teach the importance of sustainability.

While the 5.1 mile cycle from campus drive, makes for a sustainable and healthy journey, alternative transportation links shoudl be considered. According to Google Maps, there is already an existing bus network in the area, with a bus stop located at the start of Portola Rd (see the ‘X’ in the satelleite image below). As part of the site design, I would extend this bus route up Portola road, to the entrance of the Preserve (indicated by the ‘Pin’ in the image). With frequent and electric shuttle buses from campus, this 14 minute journey make the site accessible to all Stanford sutdents, and nearby residents. Additionally, this will reduce the vehicular traffic and parking in the area, thus not disturbing the local wildlife.

1.2 Detailed Site Location

The exact site location has been determined (highlighted in yellow in the Satellite image below) due to the following factors:

• Close proximity to the lake allows for natural cooling in the hot summer months and potential greywater usage.
• Proximity to existing road network, thus allowing for transportation of building materials without distrubing/damaging surrounding flora (one of my Module 3 goals)
• Views of the lake provide aesthetic benefits and follow the theme of ‘natural integration’
• Flat topography (see screenshot of Revit imported topography below) at site requires less soil excavation/importing which was one of the design targets
• Limited existing vegitation, so less trees need to be cleared
• Surrounded by trees on the east and west side to provide natural aesthetics
• Clear of trees on the south side, to provide winter passive solar heating

The climate in this area cna be described as fairly mild and dry, with a lot of diect sunlight. As shown in the two images below, the temperature does fluctuate between the seasons, with the the sky cover range following a similar trend. Note that the annual average sky cover of 40%, make this climate ideal for harnessing solar energy through PV panels, and thus aiding in achieving the 2030 Architectural goals outlined as targets in Module 2.

As shown in the Psychrometric chart below, the Stanford CA area can be described as a more mild location. In order to achieve indoor comfort, building heating should be prioritized. In fact, when completely removing active cooling, fan-forced ventilation and dehumidification, one can still achieve a 98% indoor comfort rate. Natural ventilation and sun-shading from the surrounding vegetation provide sufficient passive measures to ensure cooling during the summer months. The solar potential however, must be proiritized, in order to ensure efficient heating of the building.

General findings:

• For passive solar heating face most of the glass area south to maximize winter sun exposure, but design overhangs to fully shade in summer
• Low pitched roofs with wide overhangs works well in temperate climates
• Keep the building small (right-sized) because excessive floor area wastes heating and cooling energy
• This is one of the more comfortable climates, so shade to prevent overheating, open to breezes in summer, and use passive solar gain in winter

2. Outlining Basic Design Options

This section will briefly introduce the 4 main design options considered from this exhibition building, and a brief solar insolation analysis of each. The options will then be narrowed down and compared in detail using the respective energy models. All buildings share a similar floor area of approximately 35000 SF, which is split between 2 or 3 floors, as requested for the project

The first, and simplest design option is a basic ‘L’ shaped building envelope. By orienting the building with it’s longest wall facing south, this maximizes the solar potential during the colder winter months. As shown by the solar analysis, the rooftop provides the most solar exposure, and is thus an ideal location for the installation of PV panels.

The results appear to be promising, however a ‘Big Design’ idea outlined in previous modules was the concept of ‘tiered terraces’, to integrate the outdoors with the building itself. To simulate this, a sloped facade was created on the East side, as shown in the model below. The benefit of this, in addition to the increased outdoor area, is that it allows more sunlight to penetrate the building, allowing for passive solar heating and natural daylighting.

The average EUI for this design (without any alterations) has been found to be: 55kBtu/ft2/yr

The second design considered, involves two interior courtyards. This would allow for the integration of natural landscapes into the heart of the building envelope. With the same orienteation as option 1, a similar solar potential is seen. The key difference, however, is that the interior courtyards do not see much sunlight. Instead they are sheltered not only from the wind, but also from any solar potential, unless the

This effect can be seen in greater detail, when one analyzes the specific sun-path across the day, and months of the year. As shown in the screenshot below, when the sun is at it’s highest point in the sky, roughly around noon, the courtyard receives some direct sunlight. However, as the months approach december, or in the earlier/later hours of the day, this effect is lost.

The average EUI for this design (without any alterations) has been found to be: 57.2kBtu/ft2/yr

Expanding on the idea of an interior courtyard, the third option surrounds a hexagon design. This will allow for windows and views in all directions, while providing the same benefits of a courtyard outlined in option 2.

Again, to maximize on the tiered balconies idea outlined in previous modules, a sloped facade was create on two of the six sides of the building. The benefit of this, in addition to the increased outdoor area, is that it allows more sunlight to penetrate the building, allowing for passive solar heating and natural daylighting.

The average EUI for this design (without any alterations) has been found to be: 63.8kBtu/ft2/yr

The final of the 4 options, is the ‘Y’ shaped design. This building concept allows for two narrow branches, which could provide independent exhibitions, and a main branch. This larger main branch features tiered terraces and has a higher ceiling, allowing for an interior mezzanine. By orienting the building, so that the two narrow branches face the south, this maximizes the solar potential. This is due to the larger roof area of the two combined branches, than the single main branch. This can be seen in the solar analysis below, and would make for an ideal set-up for PV installations:

The average EUI for this design (without any alterations) has been found to be: 56.4kBtu/ft2/yr

When comparing the respective EUI of the different designs, it beocmes easier to narrow down design choices. While the design Y, 8 and L have similar base EUIs, the 63.8kBtu/ft2/yr of the Hex design suggests this would be a less ideal building design,

A more detailed comparison of the models displayed below, reveals further insights. While design ‘Y’ has a slightly higher EUI than ‘L’ and ‘8’, it has the highest potential for improvements. As seen in the comparison below, it has a min EUI value of -0.4kBtu/ft2/yr, while the other options sit at 11.3kBtu/ft2/yr, 13.1kBtu/ft2/yr and 8.4kBtu/ft2/yr.

Given the findings of section 2.5, combined with aesthetic preferences, I have narrowed down the choice between design ‘Y’ and ‘8’. A few trade-offs between the two have been listed below, that helped in making the final decision:

When comparing the advantages and disadvantages of both options side by side, it was clear that design option ‘Y’ is the preferred choice.

3. Indepth Insight Analysis (Arch. Target 2030)

When looking at the current EUI in comparison with Ashrae 90.1, Architecture 2030 and NetZero, it is clear that there is some room for improvemnet. However, given that it is the only design option with a potential net zero solution, it is important to decide which solutions are worth investing in.

Accoridng to the Energy Insights, the most efficient building orientation has already been selected when it was modelled.

Window shades provide a low cost and easily installable solution to reducing the EUI value of the buildilng. While the difference is minimal, installing shades on the South and North facing walls are significantly more effective than East and West walls.

While reducing the window to wall ratio can significantly improve the energy performance of the building due to the increased insulation, this is an element that will remain unaltered for this Module. As stated in the ‘Big Design Ideas’, connection to nature is a major theme I would like to implement for this building. Thus, flexbility on window size will allow me to maximimze the benefits of locating the centre in a national preserve.

As was shown in the psychometric chart for the project location, winter heating is a primary concern for maintaining a comfortable enviornment. It is thus no surprise, that adjusti the wall and roof insulation would have the largest effect on lowering the EUI. By using R38 wood wall construction, natural elements can be utilized, as was stated as design goal in Module 3. Additionally, R38 roof construction provides additional insulation. Higher R-values provide minimal benefits, at a higher cost and have thus not been selected.

3.6 Plug Load Efficiency

By adjsuting the power used by equipment, building EUI can usually be significantly reduced. This is a method that has seen a lot of investment and interest across the AEC industry. However, in this case I believe this effect may be infalted as the software does not know the building usage. Unlike an office or residential buildling, there will be less appliances used. However, this could be particularly useful for digital or interactive installations and exhibitions that require a lot of power.

3.6 Photovoltaics

Due to the large roof area, clear-skies and high solar exposure, it is no surprise that PV coverage has a significant impact on the EUI of the buildling. Thanks to the tiered terraces, there is sufficient space for otudoor areas with viewpoints, and thus the majority of the roof can be dedicated to PV coverage. 75% coverage and a 20 year payback limit goes a long way to achieving the 2030 Architecture goals, while 90% coverage would push the project towards being Net Zero.

This ould also allow 25% of the roof space to be used for maintenance/manouvering space, HVAC units and water tanks if required.

3.7 Overall Effect

As shown below, the combination of these changes have seen the EUI lowered to 7.21kBtu/ft2/yr, which is well below the Archituecture 2030 goal of 20.31. With these adoptions, the Sustainability Goal in Module 3 has been achieved. If a Net Zero target is desirable, WWR adjustments would see the building achieve Net Zero.

4. Detailed Building Placement

With the building layout design decided, the rough envelope can be placed on the imported topography, as shown below: