Sustainable Design - Architecture

Sustainable Design

Introduction

"The Sustainable Design section of the Autodesk Design Academy curriculum offers students great examples and lays the foundation for future study" U.S. Green Building Council (USGBC) Formal Education Committee

Sustainable design is defined as the art of designing physical objects to comply with the principles of economic, social, and ecological sustainability. It includes the design of small objects for everyday use to the design of buildings and the management of land use.

The primary goal of sustainable design is to produce places, products, and services while reducing the use of nonrenewable resources and minimizing the impact on the environment. Sustainable design is often viewed as a necessary tool for achieving sustainability. To illustrate how you can design within the sustainable design framework, you prepare the site for a residential building, design the building, and add a wind turbine to reduce the reliance on standard energy resources.

Click the link to learn about the value of Autodesk Sustainable Design.

Autodesk Sustainability Center

About This Unit

You use AutoCAD^® Architecture as you progress through the design process.

Lessons

• Architecture

• Civil Engineering

• Mechanical Engineering

Image Gallery

In this unit you will work with architectural projects. These images illustrate completed sections from referent project.

Shaded model of completed sustainable project

Shaded model of the house designed in AutoCAD Architect 2010

Shaded model of house on site designed in Revit Architecture 2008

Sustainable Design

Introduction

What is Sustainable Design for Building Designers?

The basic task for a building is to provide shelter so that people can live, gather and work within it. Providing a safe, healthy and comfortable interior environment is as important as keeping out inclement weather conditions. Buildings that are designed and constructed to work well with the environments in which they are placed perform with less environmental cost than buildings constructed without regard to local climate or site conditions.

Since the sharp rise in oil prices worldwide in the 1970's governments in climates both hot and cold have instituted regulations to reduce the energy usage of buildings, primarily by requiring insulation in floor, wall and roof cavities and by specifying the energy performance of window glass. These basic requirements represent a starting point for today's sustainable building design. "Green" buildings take into account conditions at the site, such as climate, sun, vegetation and landform. The aim is to provide the necessities of safe and comfortable habitation while reducing consumption of energy throughout the life of the building.

Lesson

• Lesson - Sustainable Design

Lesson - Sustainable Building Design

Sustainable Building Design Information

Basic Concepts

Building Size

Different types of buildings require different standards for accurate comparison. Large multistory structures have vastly different purposes and requirements from low-rise commercial buildings or single-family dwellings.

Electrical Consumption

As buildings have become more sophisticated in their use of power available from municipal electrical grids and water systems or electrically powered well pumps, the interior climate has become more separated from exterior conditions. Commercial buildings may not contain any windows, and the windows in tall office buildings generally do not open.

In warm climates, buildings use air conditioning to keep the interior cool during hot summer conditions; and in cold climates buildings contain heat sources. In moderate areas, buildings are both cooled or heated as the outside temperature rises and falls.

Modern electrical machinery produces heat as it operates. The heat from lighting, cooling, computer, or refrigeration equipment must be managed or expelled, which can add to the power consumption of a building.

Lesson Content

For simplicity, this lesson concentrates on single-family housing. Assume that the house is detached, and on a suburban size lot.

Traditional Design Approach

Materials

Prior to the nineteenth century, building materials were derived from sources close to the building site. Masonry was used below ground level, and wood or masonry was used to create the superstructure. Steel and concrete have come into wide use, and modern transportation networks enable materials to be shipped long distances.

Wood construction was post-and-beam until the mid-nineteenth century when lightweight stick framing became possible. Now most housing is built on a concrete or block foundation with a wood-framed structure; and sometimes clad with brick, stone, or other masonry.

Orientation

Urban housing has traditionally followed the layout of streets, consisting mostly of rectangular grids. The front or most important face of the house faces the street, even if that face does not contain the most windows or doors. Suburban housing, from the mid-twentieth century, has been created in developments that tend to contain curving and looping streets. Suburban houses also generally face the street.

Shape and Room Configuration

Urban housing shape is based on the shape of the building lot, which is usually long and narrow when viewed from the street. Rooms, therefore, are generally arranged from front to back with more private spaces set away from noise and traffic. Suburban houses, having generally larger lots, are often rectangular, but the pattern may be shallow and wide. If so, the entrance is usually in the middle with wings to the left and right to separate public and private spaces. Suburban houses often have many more windows than urban houses.

Sustainable Design Approach

Materials

Sustainable design principles do not mandate any particular type of material for building construction. The primary consideration is to construct a building that uses the least amount of energy during operation. It is possible to quantify the production cost of certain types of materials and choose materials that involve less power consumption in their creation or transportation. For example, wood siding is a reasonable choice in heavily forested areas, but could be an expensive, hard to maintain and energy-inefficient material for a desert location far from lumber sources.

There are many new building materials available, including prefabricated panels that use insulation materials with recycled components and high-tech materials that have varying energy transmission or retention values.

Orientation

One of the most important, basic, and inexpensive ways houses can be made more energy efficient is by orienting them to take advantage of sunlight in cool months and avoid overheating from sunlight in warm months.

The following image shows the back of a home that contains several windows. Since the home is located on a corner lot, to fit sustainable design requirements, the home is placed so that the back windows take advantage of the sunlight.

Well-designed building orientation also uses the prevailing wind pattern at the building site to capture cooling breezes in summer and lessen the power consumption requirements for air conditioning units.

Shape and Room Configuration

Sustainable design does not mandate any particular layout for a house. Good design practices already aim to minimize plumbing costs by stacking bathrooms over one another, for instance, or grouping rooms that use water close together.

Standards

This lesson meets standards for Science Content, Math, Language Arts, and Technology.

Key Terms

Evaluation

Students will be evaluated on completion of the exercises.

Resources

Exercises www.autodesk.com

Lesson - AutoCAD Architecture

AutoCAD Architecture

This lesson explores the use of sustainable design concepts in designing a single-family home using AutoCAD Architecture.

In the following exercises, you learn how to place insulation, specify R-values for walls and floors, and list glazing E-values for windows in a house location in a cold climate.

You also prepare a building model for energy analysis by creating and attaching data properties to the spaces in your drawings.

Exercises

• Add Insulation

• Specify E-Values for Windows

• Use Spaces for Energy Analysis

Exercise 1 - Add Insulation

Building insulation is used to trap air and thereby slow down the transmission of heat. Building insulation works as a total system; gaps allow heat to transfer from one area to another. In cold climates, heat escaping outdoors drives up the cost of maintaining a comfortable internal environment and can also create other problems such as roof leaks. In warm climates, heat penetrating a building drives up the cost of keeping the interior of the building cool, and in extreme cases can affect health.

In AutoCAD Architecture, you can indicate the type of insulation to use in your building using the detailing tools provided in the Detailing workspace and the Detail Component Manager.

In this exercise, you use the detail tools to add insulation to a wall and floor in your section. You also label the insulation.

Open Arch_GD_ADT_E1.dwg.

Add Insulation

1. Zoom to the bottom left corner of the cross section.

2. Activate the Detailing workspace.

3. On the Basic tool palette, click 07 - Thermal & Moisture Protection.

4. In the Properties palette:

• Verify Batt Insulation is selected from the Type list.

• Select 6-1/4" R-19 Fiberglass Batt Insulation.

5. Right-click in the drawing area. Click Left.

6. For the start point, select the endpoint as shown.

7. For the next point, select the endpoint as shown.

8. Press ENTER to end point selection. The insulation is added to the wall.

9. Right-click in the drawing area. Click Right.

10. For the start point, select the endpoint as shown.

11. For the next point, select a point as shown.

12. Press ENTER twice to end the command.

Label the Insulation

1. Activate the Document workspace.

2. On the Annotation tool palette, click Reference Keynote (Straight Leader).

3. For the object to keynote, select the insulation in the wall.

4. For the first point of leader, select the intersection as shown.

5. For the next point of leader line, select a point as shown.

6. Press ENTER twice to end the command.

Change the Keynote Display

1. Click View menu > Keynote Display > Reference Keynotes.

2. In the Select Reference Keynote Display dialog box:

• Under Field Names, select Reference Keynote - Note Only.

• Under Format, select Uppercase.

• Click OK.

The R-19 Batt Insulation is labeled without the keynote.

In this exercise, you used the detail tools to add insulation to a wall and floor in your section. You also labeled the insulation.

Exercise 2 - Specify E-Values for Windows

Choosing the type of window for a home is very important for energy efficiency. Most window manufactures will have a NFRC Energy Performance Label on their windows that gives you a quick description of the following:

• U-factor: How well a window keeps heat inside a building.

• Solar heat gain: A window's ability to block warming caused by sunlight.

• Visible light transmittance: How much light gets through a product.

• Air Leakage: A measure of air infiltration through a window.

For more information on the NFRC Energy Performance Label, visit www.nfrc.org.

A window with Low-E glass does a better job keeping heat in during the winter and out during the summer. Low-E coatings, which are microscopically thin layers of metallic oxide that are bonded to the surface of a window's glass are so thin you can see right through them, yet they prevent heat and ultra-violet (UV) rays from passing through glass. Low-e windows cost more during construction than windows with standard glass, but pays for itself over the years in utility bill savings.

Energy Star is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy to help us all save money and protect the environment through energy efficient products and practices. Look for Energy Star when you are deciding on windows and other products to use in your design. For more information about the Energy Star label, visit www.energystar.gov.

In this exercise, you edit a window schedule to indicate which windows in the home should have Low-E glass.

Specify E-Values for Windows

Open Arch_GD_ADT_E2.dwg.

Edit a Window Schedule

1. Select the windows schedule.

2. Right-click and click Edit Table Cell.

3. For the table item, select one of the borderlines of the schedule.

4. In the Edit Referenced Property Set Data dialog box, for Remarks, enter Low-E.

5. Click OK. Low-E is added to the notes of each window. This indicates to the builder to use energy efficient windows.

The Space Engineering information can now be edited for each space in the Properties palette. This information can be used in a schedule and exported to an XLS file that can be opened and edited in Microsoft Excel for energy analysis.

In this exercise, you edited the values in a window schedule.

Exercise 3 - Use Spaces for Energy Analysis

Modern tools make it possible to analyze digital building designs before construction. AutoCAD Architecture can export building model information into an XLS file that can be used for energy analysis.

The U.S. Department of Energy's National Renewal Energy Laboratory website at http://www.nrel.gov/buildings/ is a good source of information about the recognized need to lower energy consumption of buildings.

In this exercise, you define a volume property for a space style. You also attach space engineering properties to the spaces in the drawing.

Use Spaces for Energy Analysis

Open Arch_GD_ADT_E3.dwg.