D.6.1  Schematic Design

Achieving a sustainable building requires a commitment from developing the initial program documents through construction detailing and commissioning.  Initial decisions, such as the building’s location, general massing, and configuration profoundly affect the building’s environmental impact and energy performance.  Well-defined sustainable goals will guide the entire spectrum of decision-making throughout the design and construction processes.

Architectural programming establishes the needs and requirements for all of the functions in the building and their relationship to one another.  Wise programming maximizes energy savings by placing spaces in the most advantageous position for daylighting, thermal control, and solar integration.  It may also uncover opportunities for multiple functions to share space, thus reducing the gross square footage of the building.

Architectural programming involves an analysis of the required spaces to meet the functional and operational needs of the facility.  With an eye toward sustainability and energy-efficiency targets, the individual spaces should be clearly described in terms of their:

• Primary functions

• Occupancy and time of use

• Daylight potential and electric light requirements

• Indoor environmental quality standards

• Equipment and plug loads

• Acoustic quality

• Safety and security.

Similar functions, thermal zoning (See Appendix D, section 7.3.1 for more information on HVAC system zones), need for daylight or connection to the outdoors, need for privacy or security, or other relevant criteria can then be used to cluster spaces.

After completing the programming documents, careful conceptual design should strive for a building that:

• Has properly sized daylight apertures to avoid glare and maintain proper contrast ratios for visual comfort.

• Utilizes passive solar gain when the building is in heating mode.

• Minimizes solar gain when the building is in cooling mode through orientation, shading, and glazing selection.

• Facilitates natural ventilation where appropriate.

• Has good solar access if used of solar thermal or photovoltaic (PV) systems is anticipated.

D.6.1.1  Siting the Building for Solar Accessibility

Careful site selection and building placement are essential for optimal daylight and solar utilization.

• Does the building receive unobstructed solar radiation between the hours of 9 a.m. to 5 p.m.?

• Are there major sky obstructions such as geologic features, trees, or adjacent buildings?

• Does the site allow for an elongated east-west configuration?  If not, then manipulate the building shape to increase the potential for daylighting and solar load control.

D.6.1.2  Building Massing and Orientation

THE SKIN-TO-VOLUME RATIO IS THE EXPOSED SURFACE AREA COMPARED TO THE BUILDING VOLUME.

There is a trade-off between a compact form that minimizes conductive heat transfer through the envelope and a form that facilitates daylighting, solar gain, and natural ventilation.  The most compact building would be in a shape of a cube and would have the least losses and gains through the building skin.  However, except in very small buildings, much of the floor area in a square building is far from the perimeter daylighting.
A building that optimizes daylighting and natural ventilation would be shaped so that more of the floor area is close to the perimeter.  While a narrow shape may appear to compromise the thermal performance of the building, the electrical load and cooling load savings achieved by a well-designed daylighting system will more than compensate for the increased skin losses.

Appendix d