Ask the Green Architect: LEED Consulting; Sizing Solar Panels; the First Green Building

Ask the Green Architect: LEED Consulting; Sizing Solar Panels; the First Green Building

Green architect Eric Corey Freed answers your questions on sustainable building performance, materials, and design.


  • LEED Consulting
  • Sizing Solar Panels
  • The First Green Building

    I'm a LEED Accredited Professional and want to consult to project teams to perform the LEED certification. What fees are appropriate for my services? Is there an industry standard? Any other costs to consider?

    LEED (Leadership in Energy and Environmental Design) Green Building Rating System) is a points based rating system and the industry leader as a recognized and respected brand.

    Today, LEED buildings can be found in all 50 states and 24 different countries. There are currently over 24,000 LEED Accredited Professionals and over 3,000 buildings on their way to certification. This represents about 8% of the U.S. new construction market, and this number is growing quickly.

    To date, LEED has been adopted by nine federal agencies, 15 states and 49 cities as the standard in the construction of all municipal facilities.

    The first step toward getting any building LEED certified is by registering online at the USGBC Web site. The fee for this is a simple flat cost of $450 for members ($600 for non-members).

    Depending upon the project, you should select the appropriate version of the LEED system. Currently, the USGBC offers the following types:
  • LEED-NC: New commercial construction and major renovation projects
  • LEED-EB: Existing building operations
  • LEED-CI: Commercial interiors projects
  • LEED-CS: Core and shell projects
  • LEED-H: Homes
  • LEED-ND: Neighborhood development

After a project is registered, the project team can immediately begin to prepare the massive amount of documents required using the helpful USGBC provided templates. A building must earn points in order to achieve the various levels of certification (Certified, Silver, Gold and Platinum). It is at this stage a LEED Accredited Professional would be the most helpful and useful to manage this paperwork.

The USGBC recently introduced several clever refinements to reduce the time, cost and paperwork of achieving LEED certification. Online paperless submittals, a revised website and in-progress documentation (don't do it all at once) are some of these ideas.

The earlier in the project the LEED process is started, the easier time the project team will have in making decisions about the various points.

In regard to your specific question, the fees for a LEED Accredited Professional could range based on the schedule, the level of certification sought, the difficulty in documenting the points and even how early in the design process documentation begins. The size of the building does not appear to influence the amount of money being spent on documentation.

Here is a good rule of thumb: Between 0.5% to 1% of construction costs -- the smaller the project, the larger the percentage.

Thorough documentation costs between $6,000 and $75,000 per project, with the range highly dependent on the experience of the team documenting the LEED process. More experienced teams seem to charge less.

A recent survey (PDF) showed as big a range of .5% of construction costs up to $75,000 for LEED documentation. Another report (PDF) discusses all of the costs for LEED, including design.

The fees are warranted by the large amount of time it takes to document each point. It is no uncommon for it to take one month or more to gather all of the required information.

You can also help justify these fees by reminding your clients the use of a LEED Accredited Professional will earn them a valuable and easy point.

Given the overwhelming adoption of LEED as a standard, the more people fluent in the point system and how to charge for these services, the better.

More Information:

The Cost of LEED Certification

Analyzing the Cost of Obtaining LEED Certification (PDF)

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Do you have any good rule of thumb for sizing solar panels?

Your question is difficult to answer in that so many factors determine size (and cost) for solar panels.

The amount of solar needed to power a building is not dependent on the size of the building. The amount of solar modules you need depends on the amount of power you use. So, your first task is to determine how much energy is needed.

Calculate Your Usage

A simple method to figure out your electricity usage is to collect a years worth of utility bills (the utility company can provide you with copies). If you do not have an entire year, use as many as you can. Since usage varies throughout the course of a year, the more bills you have, the more accurate your total usage.

Look at each monthly bill and locate the total amount of power (kWh) used in the last billing cycle. Divide this by the number of days in the billing cycle. This will tell you how much power you use each day (kWh).

Since this is past usage, you may wish to account for future energy needs or future energy conservation measures. The goal is to get an accurate estimate of your power requirements.

Map Your Location

The efficiency of any solar panel is dependant upon its' geographic location. Using an Insolation Map (below), it is easy to determine the average worst case insolation hours. Insolation hours are a way of estimating the output of a solar module in a specific location. For example, if you have a solar module that produces 4A peak power in a location that has three hours of insolation, that module will produce 12AH a day.

NOTE: The insolation numbers here are only a guideline. Check with your solar installer for accurate and location specific information.

Select a System

Given your usage and location, you should be able to select a system with a local provider. The location of the panels, as well as the pitch of the roof, will determine their efficiency. A good south or south-west facing roof area is best.


Prices for a solar system will vary greatly based on:

  • amount of power needed;
  • roof location and space; and
  • geographic location (insolation hours).

As a rule of thumb, take your total annual kilowatt hours (kWh) from the utility bills and divide that number by 1930. This will give you the approximate size of your system in kilowatts. Each kilowatt will cost between $5000-9000 installed (before rebates). Cost and available rebates vary by region.


For every 100 square feet, integrated solar panels produce between 1 to 1-1.5 kW. So a 5 kW system would require about 500 square feet.

Again, this varies based on geography and solar orientation.

Example Of Costs

  • If your annual electricity costs are $2000 you are probably using about 13,333 kWh per year, so you would need a 6.9 kW system to produce 100% of your power needs.
  • Installed cost would be around $58,500
  • Rebates would reduce that by $19,300.
  • Your final cost would be $39,200 (out of pocket).
  • If you factor in tax credits, that net cost drops to around $14,000.

Other Methods

Online you can find dozens of worksheets to size solar panels such as this one or this one but these tend to be complex and confusing.

Remember, solar panels require light, not heat. A cold and sunny location works just as well.

More Information:

Million Solar Roofs Initiative
This initiative hopes to help businesses and communities install solar systems on one million rooftops across the United States by 2010.

Financial Incentives for Solar Energy
Lists the incentives and rebates in California for Solar Panels.

Photovoltaic performance calculates assesses typical performance of solar electric arrays for more than 200 locations in the National Solar Radiation Database.

The Database of State Incentives for Renewable Energy (DSIRE)
A comprehensive source of information on state, local, utility, and selected federal incentives that promote renewable energy. DSIRE now includes state and federal incentives for energy efficiency.

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When and where was the first-ever Green Building and was it a commercial facility?

Although you were seeking a modern example, perhaps the first truly green buildings were the stone dwellings of the Anasazi Indians from AD 1.

The Anasazi were a rich culture of farming people who lived in the Four Corners region (Colorado, New Mexico, Arizona, Utah) up until 1300 when drought forced them to migrate. The best examples of their buildings appeared around AD 700, and consisted of apartment-house style villages. These villages, built at the top of mesas, included multiple-room dwellings of beautiful stone masonry.

Why are the pueblos of the Anasazi considered to be a green building? The Office of the Federal Environmental Executive ( defines green building as:
"the practice of 1) increasing the efficiency with which buildings and their sites use energy, water, and materials, and 2) reducing building impacts on human health and the environment, through better siting, design, construction, operation, maintenance, and removal -- the complete building life cycle."

Using this criteria, how do the ancient Anasazi hold up to our "modern" green standards?

  • Sustainable Siting: understanding the sun and heating, the Anasazi oriented their dwellings to the light. These are textbook passive solar buildings featuring natural ventilation.
  • Water Efficiency: rainwater is captured and irrigated since water is seen as a valuable resource.
  • Energy Efficiency: the Anasazi buildings pre-dated electricity, but were heated and cooled without heat or air conditioning. Imagine that!
  • Materials and Resources: natural stone, mud and wood are the only materials used.
  • Indoor Environmental Quality: the buildings of the Anasazi are completely non-toxic and healthy.
  • Community Development: centered around a village concept, the Anasazi buildings foster interaction and a sense of community.

I selected this to also make a point. Many of the so-called "innovative" features we marvel at today are ancient methods of building. Fresh air, passive solar orientation, passive cooling and many other concepts have been in use for thousands of years. It is only the last generation of architects who have forgotten how to build in a natural way. As William McDonough says, "We thought using operable windows made sense, but everyone else though it made news."

Modern Examples

The global energy crisis of the 1970's brought some pioneering efforts in energy conservation. Arguably, the pioneering Willis Faber and Dumas Headquarters by Norman Foster could be considered the first modern green building.

Built in 1977, the building features a grass roof, a daylighted atrium, and mirrored windows used to reduce solar gain. An interesting side note: Foster collaborated with Buckminster Fuller on several projects between 1971 and 1983.

Again, why could we consider this a green building?:

  • Sustainable Siting: The building is located in the center of the town of Ipswich, centrally located for ease of access.
  • Water Efficiency: The building features a landscaped roof garden.
  • Energy Efficiency: The glass curtain wall is tinted to counter solar gain and is suspended from a continuous clamping strip.
    The building's design exhibits a pioneering use of low-energy consumption.
  • Materials and Resources: An irregular shape of black glass creates a striking and natural form.
  • Community Development: The building is designed to encourage social contact. These social ideas shaped the arrangement of the plan.

Finally, another worthy building to mention is the Philip Merrill Environmental Center, in the Chesapeake Bay. It was the first LEED Platinum building and is recognized as one of the "greenest" buildings ever constructed.

Featuring solar hot water heaters, rain water cisterns, a geothermal heat pump and composting toilets, the Center stands as an excellent example of a modern day green building.

In the (near) future, buildings such as these will be commonplace. Perhaps by looking to the past we can also learn what we have forgotten about building.

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Eric Corey Freed is principal of organicARCHITECT and teaches sustainable design at the Academy of Art University in San Francisco and University of California Berkeley. He is on the boards of Architects, Designers & Planners for Social Responsibility (ADPSR), Green Home Guide, and West Coast Green.