The following is a set of modifications to the Model Energy Code which, taken together with that code, will constitute the Tucson / Pima County Sustainable Energy Standard, or Civano Energy Code. It was developed by the Tucson / Pima County Energy Codes Committee and has been reviewed by the Tucson / Pima County Building Code Committee.

This standard will be attached to the Memorandum of Understanding executed by the City of Tucson and the developers of the Community of Civano. It will serve as the statement of energy requirements for all buildings in Civano.

It is the intention of the Energy Codes Committee that this document will also serve as a voluntary sustainable energy standard for other buildings throughout Tucson and Pima County. It provides a quantifiable standard against which building plans can be measured to ensure that the finished buildings can be expected to enjoy substantially less energy usage than would have been the case under the Model Energy Code.

SUSTAINABLE ENERGY STANDARD
4/22/98

The following modifications to the CABO Model Energy Code, 1995 Edition are deemed to be a sustainable standard:

(Editorial Note: This Energy Standard was reviewed by the Tucson/Pima County Building Code Committee and is regionally specific to the Tucson Metro area.)

Material to be added is shown in italics. Material to be deleted is shown as strikeout.

Section 101.4 Scope. Add a paragraph to read:
The calculated Target annual energy consumption of the building shell and mechanical system and domestic hot water heating shall be less than the energy required by the present Tucson/Pima County Model Energy Code by 50 percent.

Section 102.1.3 Add to first paragraph: , and there shall be a verification of proper installation before drywall installation and the completion of the "Insulation Installation Warranty" and signature` by a representative of the developer and builder.

Section 102.2 Maintenance Information. Delete the first two sentences.

Section 102.3 Change the first sentence to read: Whole-window assembly U-factor, solar heat gain coefficient, visible light transmittance and air leakage values of fenestration products ...

Table 102.3a Add the following notes at the end of the table:
The minimum design characteristics to qualify as a Thermal Break are:

Section 102.4 Equipment. Add a new subsection to read:
102.4 Equipment. Residential buildings constructed under the provisions of this standard shall be permitted to use refrigerated air conditioning systems selected under the guidelines of the Air Conditioning Contractors of America (ACCA) Manual J Procedures, Specifically Sections 7-27, 7-28 and 7-29 at outside conditions of 105 degrees F. and inside conditions of 75 degrees F. Other provisions of this standard notwithstanding, air conditioning equipment shall have a minimum SEER of 12 or a minimum EER of 10.

Section 104.1 General. Delete parenthesis around last sentence, delete the Footnote.
Add a sentence after the exception to read:
Plans and specifications shall show the method of utilizing "beneficial use of solar energy".

CHAPTER 2
DEFINITIONS

Section 201 Definitions. Revise as follows:
201.1 Application of Terms. Conditioned Floor Area:
Delete the words "The horizontal projection of", and capitalize the new first word "That".

201.1 Application of Terms. Positive Cooling Supply.
Insert including evaporative cooling systems, between "cooling" and "deliberately"

Add a new subsection:
201.1 Application of Terms. Civano. A Tucson Solar Village, a model sustainable community; a vision of the future where resource consumption is reduced through more efficient technologies, use of solar energy and lifestyles which promote greater harmony and balance with the natural environment; a community in the spirit of the "Civano" period, a golden era of the Hohokam culture which balanced natural resources and human needs; incorporates and demonstrates strategies for achieving more sustainable development.

201.1 Application of Terms. SOLAR ENERGY SOURCE. Revise to read:
Natural daylighting or thermal, chemical or electrical energy derived directly from conversion of incident solar radiation.

201.1 Application of Terms. Water-chilling Package of Absorption. Revise to read:
Water-chilling package, absorption.

Table 302.1 Exterior design conditions. Revise the table as follows:

Table 302.1
Exterior Design Conditions³

Add a new section to read:

304.2 Wood-burning stoves. Wood-burning stoves shall be labeled to show compliance with the following U. S. Environmental Protection Agency (EPA) standards for particulate emissions during operation:

Stoves with catalytic elements	4.1 grams per hour
Stoves without catalytic elements	7.5 grams per hour

Direct vent gas fireplaces shall have a minimum of 70% overall efficiency.

Section 402.1 Energy Analysis. Change the first paragraph to read:

402.1 Energy Analysis. Compliance with this chapter will require an analysis of the annual source energy usage as required in section 101.4, hereinafter called an annual energy analysis or shall not exceed the source energy usage shown in Table 402.1.

402.1.1 Input Values for Group R Buildings. Add a sentence at the end of the first paragraph to read:
Domestic hot water energy use must be calculated separately from glazing systems, heat storage, thermal envelope and space conditioning equipment and must meet the energy reduction percentages of section 101.4.

Distribution System Loss Factor on page 12: Change the Outside factor for Cooling to read 0.75.

Add the following:
402.1.1.1 Thermal Mass. Designs utilizing thermal mass may be used provided the materials' volumetric heat capacity is between 18 minimum to 30 Btu/cu.ft. F (except water walls) and meet the values shown in Table 402.1., with walls without external insulation at least 12 inches minimum thickness or 8 hours time lag. External insulation can be used (R-9 to R-11) to reduce thickness of thermal mass to no less than 4". Surface area of uncovered thermal mass (in the direct sun zone) will be minimum 9 times the area of south glass, with 1ft² of additional south glass for every 40 ft² of mass located outside the direct sun zone (a simplified method of calculating thermal mass and south glass areas).

Table 402.1
Heat Storage Properties of Materials

402.1.1.2 Summer Ventilation. Thermal-mass buildings shall be provided with a means of venting to the outside at night during the months of May through October to avoid overheating. Operable windows totaling at least 20 percent of the total glazing area, located for effective cross-ventilation or ceiling fans or a whole-house fan sized to provide 10 air changes per hour may be used.

Section 402.4 Calculation Procedure. Operational Characteristics. Add a sentence to read:
The occupied mode shall be not less than 10 hours in a 24-hour period.

Section 402.5 Documentation. Delete the exception.

CHAPTER 5
RESIDENTIAL BUILDING DESIGN BY COMPONENT
PERFORMANCE APPROACH

Section 502.1 General. Add:
Thermal design parameters to be used in this chapter are found in Chapter 3, Section 302.1.

Section 502.1.2. Revise the second paragraph by placing a comma after "Masonry", and adding "earthen materials," between "Masonry" and "or".

Table No. 502.1.2c Delete the phrase " ,SUCH AS A LOGWALL " in the heading.

Section 502.2.1 Walls. Add a subsection to read:
502.2.1.2 Glazing. All glazing facing between 20 - 165 degrees or 195 - 340 degrees shall have a minimum summer shading coefficient of 0.39. All glazing facing between 165-195 degrees shall have a minimum summer shading coefficient of 0.5 or less. This may be accomplished by the use of overhangs, covered porches, tinted glazing, or other approved methods.

Table 502.2.1a Revise as follows

Table 502.2.1a¹
HEATING AND COOLING CRITERIA

¹ Values are determined by using the graphs (Figure Nos. 1, 2, 3, 4, 5 and 6) contained in Chapter 8 using heating degree days as specified in Section 302.
² Basement and crawl space wall U values shall be based on the wall components and surface air films. Adjacent soil shall not be considered in the determination of the U value.
³ Typical foundation wall insulation techniques can be found in Standard RS-20 listed in Chapter 8.

Add a new section 502.2.1.1 to read:
502.2.1.1 Software. Model Energy Code (MEC) software (DOS Version) called MEC check is available to verify compliance with this standard. It is available for download free from the Internet at:

http://www.energycodes.org/meccheck/mecdownload.html

To use the software:

Use DOS to modify the LOCATION file line 188 to read: Civano Tucson,7000,34892
Save the file and open the program.
Under state, select Arizona and under city, select Civano Tucson.
Select "Trade-offs" from the top bar and set HVAC Efficiencies for an air conditioner value of SEER 12.0 or better and Furnace AFUE to 80 or better. Corresponding heat pump values may be used.
Enter the building components and verify the building meets the MECcheck criteria.
Print the report with the check list (see Table 502.2.1.1 below) and submit for a permit.

Table 502.2.1.1
Check List to Accompany MEC Check Report when using Chapter 5

Section 502.2.4 Slab-on-grade floors. Delete in its entirety.

Section 502.3 Add the following sentence at the end:
An Air Leakage Warranty verifying a maximum of 0.35 ACH shall be provided to the home owner. A representative of the developer and/or builder will perform a blower door test after completion but before occupation of the residence. The representative will certify a maximum of 0.35 ACH based upon the results of the blower door test. An Air Leakage Warranty verifying a maximum of 0.35 ACH shall be provided to the homeowner.

Section 502.3.4 Recessed lighting fixtures. Revise the first paragraph to read:
503.2.4 Recessed Lighting Fixtures. When installed in the building envelope, recessed lighting fixtures shall be constructed so as to accept only lamps with efficacy greater than 40 lumens/watt, and meet one of the following requirements:

Section 503.2.1 Calculation Procedures. Add a sentence to read:
Equipment not covered by the tables in this section shall show the following maximum installed cooling power densities, including all auxiliaries:

Table 503.35a Change the SEER values in the fourth column (Minimum Performance) from 10 and 9.7 to 12.0 and 10, respectively. Add the following note at the bottom of the table:
Note: Air-conditioning may be used selected under the guidelines of the Air Conditioning Contractors of America (ACCA)Manual J Procedures, Specifically Sections 7-27, 7-28 and 7-29 at outside conditions of 105 degrees F. and inside conditions of 75 degrees F.

Section 503.4 Add new sub-section to read:
503.4.3 Speed Reduction. An automatic method of speed reduction for pump and fan motors, or air or water flow reduction, during less than full system load conditions, which assures energy savings through motor power input reduction, shall be employed for any air system that exceeds a total system static pressure of 2.0 inches water gauge, and any water system that exceeds a total water system pressure equivalent to a 50 foot head of water.

Section 503.5 Balancing. Add a new second sentence to read: For structures with a floor area greater than 5000 square feet with forced-air climate control, balancing shall be performed, or included as part of a commissioning process from the design and construction phase. Certification and results of the balancing shall be submitted to the jurisdiction, the owner and the designer of the project.

Section 503.8.1 Delete in its entirety and add: All ducts shall be leak tested in accordance with this standard. The tested rate of air leakage is not to exceed 3% of conditioned floor area in CFM at 25 pascals (0.1 inches WC). A representative of the developer and/or builder will perform a field inspection and leakage test of the ductwork before drywall installation. The field representative will certify successful completion of this test.

Section 503.9 Piping Insulation. Delete exceptions 2 and 4, and renumber exception 3 to 2.

Section 504.2.1.1 Electric Water Heaters. Revise to read:
All Automatic electric storage water heaters shall have a standby loss not exceeding 4.0 watts/ft² (43W/m2) of tank surface or 43 watts, whichever is greater, when tested in accordance with Standard RS-5 listed in Chapter 8 and calculated at a 30 Degrees F. temperature difference.

Section 504.5.1 Add the following at the beginning of the paragraph:
All recreational swimming pools and spas shall utilize solar energy as the only water heating source. Medical and rehabilitation pools smaller than 3,000 gallons water capacity shall use solar energy as the primary water heating source, with a new energy source permitted as backup.

Add a new Section 504.5.4:
Section 504.5.4 Recirculating Systems. Recirculating systems shall be provided with time clocks as required in Sec. 504.5.3, switches as required in Sec. 504.6, and pipe insulation as required in Sec. 504.7.

Section 504.8 Conservation of Hot Water. Delete in its entirety and add "Plumbing fixtures shall meet the following maximum usage requirements unless special requirements dictate otherwise:

Add a new section 506 to read:
Section 506. Energy Consumption - Other Than Electrical. In multifamily dwellings , provisions shall be made to determine the energy consumed by each tenant by separately metering individual dwelling units or tenant spaces.

CHAPTER 6
RESIDENTIAL BUILDING DESIGN BY ACCEPTABLE PRACTICE

Section 602.2.1 Walls. Add the following paragraph to read:

1. Nominal 2 x 6 wood-frame construction insulated with R-19 batts or applied blown-in process custom cavity filling insulation.
2. Nominal 2 x 4 wood-frame construction insulated with R-13 batts or applied blown-in process custom cavity filling insulation and rigid insulation board on the exterior with an R-Value of not less than 3.2, with a nominal 4 inch brick veneer.
3. Nominal 2 x 4 wood-frame construction insulated with R-13 batts or applied blown-in process custom cavity filling insulation and rigid insulation board on the exterior with an R-Value of not less than 6.0.
4. Earthen material or solid masonry, at least 4 inches in thickness with insulation with an R-Value of not less than 9.0 applied to the exterior.
5. Earthen material or solid masonry, at least 12 inches in thickness or 8 hours time lag.
6. Straw bales at least 14 inches in thickness.
7. Log or solid wood construction with an average thickness of 12 inches.
8. Log or solid wood construction with an average thickness of 6 inches with nominal 2x4 frame construction insulated with R-13 batts or loose fill insulation on the inside.
9. Structural insulated panels with a minimum R value of 25.

Add the following exceptions after the last paragraph:
Exceptions:

1. Doors whose area and U-value are considered as glazing in section 602.2.1 shall be exempt.
2. One exterior swinging door with a maximum area of 32 square feet may be installed for ornamental, security or architectural purposes and be exempt from these requirements.

Add new subsections to read:
602.2.1.1 Exterior Door Area. For doors containing at least 20 percent of the door area in glazing, the glazing area shall be subtracted from the door area for the purpose of determining the U-value of the door.

602.2.1.2 Exterior Door U-value. All exterior doors shall have maximum area weighted U-value not exceeding that prescribed in Table 102.3b.

Table 602.2.1.3

602.2.1.4 Summer Ventilation. Buildings utilizing thermal-mass (items 4 and 5, in section 602.2.1.1) shall be provided with a means of venting to the outside at night during the months of May through October to avoid overheating. Operable windows totaling at least 20 percent of the total glazing area, located for effective cross-ventilation and ceiling fans or a whole-house fan sized to provide 10 air changes per hour may be used.

Section 602.2.2 Roof/ceiling. Add a new subsection to read:

Section 602.2.4 Slab-on-grade Floors. Delete 2nd paragraph and insert the following sentence:
At least 25 percent of the floor area in the living space shall be without carpet or an equivalent area of internally exposed mass.

Section 602.3 Add the following sentence at the end:
An Air Leakage Warranty verifying a maximum of 0.35 ACH shall be provided to the home owner per Section 502.3.

Section 603.2 HVAC Equipment Requirements. Change to read:
. . . efficiency and power density requirements of section 503.2, 503.3 and 503.8.1.

Table 603.5 Minimum Pipe Insulation. Revise by changing the numbers 1 1/2 to 1/2 in the third and fourth columns on the line "CHILLED WATER".

Section 603.6 Add a new section to read:
603.6 Space Cooling. Buildings constructed under the provisions of this standard shall be permitted to use refrigerated air conditioning systems selected under the guidelines of the Air Conditioning Contractors of America (ACCA)Manual J Procedures, Specifically Sections 7-27, 7-28 and 7-29 at outside conditions of 105 degrees F. and inside conditions of 78 degrees F. Other provisions of this standard notwithstanding, air conditioning equipment shall have a minimum SEER of 12 or a minimum EER of 10. System sizing shall be determined by an analysis consistent with industry standards.

Section 603.7 Add a new subsection to read:
603.7 Mechanical Equipment and Water Heater Efficiency. The efficiency of water heating and mechanical equipment shall be in accordance with sections 101.4, 102.4 and 503 of this standard.

Section 604.1.2.3 Swimming Pools and Spas. Add the following at the beginning of the first paragraph:
All recreational swimming pools and spas shall utilize solar energy as the only water heating source. Medical and rehabilitation pools smaller than 3,000 gallons water capacity shall use solar energy as the primary water heating source, with a new energy source permitted as backup. When permitted, spa and Ppool . . . . . remainder unchanged.

Section 604.2 Water Heaters, Storage Tanks and Boilers. Add a sentence to read:
Shall comply with Section 101.4 and 102.4 of this standard.

Section 604.4 Conservation of Hot Water. Delete in its entirety and add: "Plumbing fixtures shall meet the following maximum usage requirements unless special requirements dictate otherwise:

- Water closets: 1.6 gallons per flush.
- Kitchen showers and lavatory faucets: 3 gallons per minute.
- Urinals: 1 gallon per flush.

CHAPTER 7
BUILDING DESIGN FOR ALL BUILDINGS OTHER THAN
RESIDENTIAL BUILDINGS

Section 702.1 Basic Requirements. Revise to read as follows:

702.1 Basic Requirements. Building designs shall meet the requirements of Section 101.4 and 102.4 of this standard as well as the requirements of Sections 5.4, 6.4, 7.4, 8.4, 9.4, 10.4, 11.4 and 12.4 in Standard RS-22 listed in Chapter 8.

Section 702.2 Additional Requirements. Add the following before the first exception:
Buildings otherwise meeting the requirements of Chapter 4, 5 or 6 of this standard may employ the following performance requirement substitutions of Standard RS-22, listed in Chapter 8.
Remainder unchanged.

Add a new section to read:

Occupancy Sensors shall be specified and installed in accordance with EPA Green Lights guidelines, with control technology appropriate to the application. Areas with video display terminals shall be primarily illuminated by task lighting, use of overhead luminaries in each space to be evaluated for Visual Comfort Probability. Visual acuity factors are to be treated as minus weighting factors.