4324277 Zoning Commission Second Notice of Proposed Rulemaking: Case No. 12-10 (Text Amendment, New Chapter 34, Green Area Ratio)

ZONING COMMISSION FOR THE DISTRICT OF COLUMBIA

SECOND NOTICE OF PROPOSED RULEMAKING

Z.C. Case No. 12-10

(Text Amendment – 11 DCMR)

(New Chapter 34, Green Area Ratio)

 

The Zoning Commission for the District of Columbia (Commission), pursuant to its authority under § 1 of the Zoning Act of 1938, approved June 20, 1938 (52 Stat. 797; D.C. Official Code § 6-641.01 (2008 Repl.)), hereby gives notice of its intent to amend the Zoning Regulations, Title 11 (Zoning) of the District of Columbia Municipal Regulations (DCMR), by adding a new Chapter 34, Green Area Ratio. 

 

The Commission had originally proposed the new chapter in a Notice of Proposed Rulemaking published in the  D.C. Register on January 11, 2013 at 60 DCR 224.  That notice also included a proposal to add a new § 412, Pervious Surface Minimum Requirements for R-1 through R-4 Zone Districts, and a new § 2111, Surface Parking Lots Landscaping Standards.  No changes are proposed for those two sections. 

 

However, as a result of comments received with respect to new Chapter 34, the Commission is proposing certain changes in the published text to add additional exemptions, provide for an effective date of October 1, 2013, and to not apply a green area ratio requirement to compliant building permit applications filed prior to the effective date and to certain building permit applications filed after that date.  Normally, zoning construction rights do not vest until permit issuance pursuant to 11 DCMR § 3202.4, with the exception of construction authorized by an order of the Board of Zoning Adjustment.

 

In addition, insertions and deletions are proposed for the following three (3) subsections (additions shown in bold and underlined text and deletions shown in strikethrough text):

3402.5             If multiple landscape elements occupy the same area, for example groundcover under a tree or trees and shrubs on an intensive green roof, the full square footage or equivalent square footage of each element may be counted.

3403.3             Bioretention facilities shall be landscaped areas that receive rainwater from surrounding areas and use plants and soils to slow, filter, and infiltrate stormwater runoff.  Bioretention facilities include but are not limited to rain or rainwater gardens, bioretention planters, Baysavers, or linear cells or swales.  These do not include structures made of cement or concrete alone.

3403.6             Vegetated roofs shall meet the following conditions:

(a)                Designs for vegetated roofs must include plans to provide supplemental water;

(b)               Where stormwater harvesting for irrigation is proposed, vegetated roofs shall contain a connection to the proposed irrigation system; and

(c)                The groundcover vegetation on a vegetated roof is not additionally eligible for groundcover value towards GAR requirements. 

 

All comments received in response to the initial notice of proposed rulemaking will remain in the record.

 

Final rulemaking action shall be taken in not less than thirty (30) days from the date of publication of this notice in the D.C. Register.

 

Title 11 DCMR (Zoning) is proposed to be amended as follows:

 

A new Chapter 34, GREEN AREA RATIO, is added to read as follows:

 

3400                Introduction to green area ratio

3401                Applicability of Green Area Ratio Standards

3402                Calculation of Green Area Ratio

3403                Landscape element conditions for green area ratio

3404                submittal requirements for green area ratio

3405                Special Exceptions for Green area ratio

3406                maintenance requirements for green area ratio

 

Chapter 34 green area ratio

3400                    Introduction to green area ratio

3400.1              Green Area Ratio (GAR) is the ratio of the weighted value of landscape elements to land area.  The GAR score relates to an increase in the quantity and quality of environmental performance of the urban landscape.

3400.2              Green Area Ratio sets integrated environmental requirements for landscape elements and site design that contribute to the reduction of stormwater runoff, the improvement of air quality, and the mitigation of the urban heat island effect.

3400.3              The purposes of the GAR regulations are to:

(a)                Implement a value-based system of requirements for environmental site design that provides flexibility in meeting environmental performance standards; and

(b)               Promote attractive and environmentally functional landscapes.

3400.4              The purpose of this chapter is to:

(a)                Provide general guidance about the regulation of GAR requirements;

(b)               Define the applicability of GAR;

(c)                Set forth the formula for calculating the GAR and define its component parts;

(d)               Identify those landscape elements that are included in the GAR, explain how their area is measured, and set forth eligibility conditions;

(e)                Establish multipliers for each eligible landscape element;

(f)                Indicate what plans and certifications must accompany an application submitted to demonstrate proof of GAR compliance; and

(g)               Establish maintenance requirements for the landscape elements that are provided as part of a property’s GAR requirement.

3401                    applicability of green area ratio standards

3401.1                    The requirements of this chapter shall become applicable October 1, 2013.             

3401.2                          Except as provided in § 3401.3 and pursuant to the conditions and requirements of this chapter, properties in zones listed in the following table shall provide a GAR as specified in the following table:

 

Zone District	Green Area Ratio
R-5-A and R-5-B	0.40
R-5-C, R-5-D and R-5-E C-1, C-2-A, C-2-B and C-2-C W-1, W-2, W-3 SP-1, SP-2	0.30
C-3-A, C-3-B	0.25
C-3-C, C-4, C-5, CR and any property within the DDD overlay	0.20
CM-1. CM-2, CM-3 and M, all structures except one story warehouses one story warehouses	0.30 0.10

 

3401.3                          The GAR standards set forth in this chapter shall apply to all new buildings and to all existing buildings where any additions within any twelve (12) month period exceed one hundred percent (100%) of the assessed value of the building as set forth in the records of the Office of Tax and Revenue as of the date of the building permit application, except:

(a)                Buildings that do not require certificates of occupancy;

(b)               Municipal wastewater treatment facilities operated by the District of Columbia Water and Sewer Authority;

(c)                The interior renovation of an existing building that:

           

(1)               Is located in the Central Employment Area;

 

(2)               Has an existing 100% lot occupancy prior to the filing of the building permit;

 

(3)               Has an existing roof that cannot support a dead load of four inches (4 in.) of growth medium on the roof; and

 

(4)        The work proposed by the building permit application will not result in a roof capable of supporting a dead load of four inches (4 in.) of growth medium on the roof; or

(d)               A historic resource and any additions thereto subject to the provisions of § 3401.7.

 

3401.4                          Notwithstanding §§ 3202.4 and 3401.2, the provisions of this chapter shall not apply to any application for a building permit:

(a)                That has been officially accepted by the Department of Consumer and Regulatory Affairs as being complete prior to October 1, 2013 if the building permit plans are consistent; or 

(b)               Filed on or after October 1, 2013 if the building permit plans are consistent with:

 

(1)               An unexpired approval of a planned unit development, variance, special exception, design review under the CG or SEFC overlay, or concept design by the Historic Preservation Review Board or Commission of Fine Arts; provided the vote to approve occurred prior to October 1, 2013:

 

(2)               An unexpired approval of a variance, special exception, or design review under the CG or SEFC overlay granted on or after October 1, 2013, for which a public hearing was held prior thereto;

 

(3)               An unexpired approval of a planned unit development that was granted after October 1, 2013, but which was set down for a public hearing prior thereto;

 

(4)               A Large Tract Review completed prior to July 1, 2012 subject to the following:

 

(A)             The application shall be filed no later than July 1, 2014;

 

(B)              The application shall be consistent with the conditions of the Large Tract Review;

 

(C)              The building shall achieve a GAR of no less than 0.1; and

 

(D)             This subparagraph shall expire on July 2, 2014.

 

3401.5              Any approved change or modification to a permit, project or application in §§ 3401.3 and 3401.4 that results in an increase in impervious surface or lot occupancy of twenty percent (20%) or more shall cause the GAR to be applicable for that portion of a project that is effected by the modification. 

 

3401.6                          In addition to meeting the applicable burden for obtaining further processing approval under a campus plan to construct or add to a building, the college or university applicant shall demonstrate the extent to which the building or addition meets the GAR standards.  Further processing approval shall include the determination by the Zoning Commission that the proposed building is complaint with the intent of the GAR regulations.

 

3401.7                          A historic resource and any additions thereto are exempt from the requirement of this chapter as a result of a change of use or an increase of intensity of use, except that this chapter shall be applicable when any addition results in an increase in the gross floor area of the historic resource by 50% or more. For the purposes of this chapter a “historical resource” is a building or structure listed in the District of Columbia Inventory of Historic Sites or a building or structure certified in writing by the State Historic Preservation Officer as contributing to the character of the historic district in which it is located.

3401.8                          The cost basis for additions, alterations or repairs to an existing building shall be the amount indicated by the applicant on the application for a building permit.

3402                                CALCULATION OF GREEN area ratio

3402.1                          The GAR shall be calculated using the following formula:

 

(area of landscape element 1 x multiplier)+

GAR =            (area of landscape element 2 x multiplier)+…

                                                                        Lot Area

3402.2                          For the purposes of the above formula and the remainder of this chapter:

(a)                The term “landscape element” refers to one of the elements listed in the table in § 3402.9, and will be hereafter referred to as “landscape element” or “element;”

(b)               The term “multiplier” refers the number listed the Table in § 3402.9 that corresponds to a “landscape element”; and

(c)                The “area of landscape element” shall be  the square feet of a landscape element, unless the element is a tree or large shrub, in which case “area of landscape element” refers to the element’s equivalent square footage as indicated in  § 3402.7.

3402.3                          The process for calculating a property’s GAR under the formula is as follows:

(a)                The area of each landscape element is multiplied by its corresponding multiplier;

(b)               The resulting numbers for all landscape elements are added together;

(c)                The resulting point total is then divided by the total land area of the lot; and

(d)               The product of the equation equals the property’s GAR.

3402.4                          The total points for all permeable paving and enhanced tree growth credits may not count for more than one-third (1/3) of the GAR score for a lot.

3402.5                          If multiple landscape elements occupy the same area, for example groundcover under a tree or trees and shrubs on an intensive green roof, the full square footage or equivalent square footage of each element may be counted.

3402.6                          A landscape element must meet the eligibility conditions of § 3403.

3402.7                          Equivalent square feet of tree canopy and large shrubs are identified in the table below.

GREEN AREA RATIO LANDSCAPE ELEMENTS	EQUIVALENT SQUARE FOOTAGE
Plants, not including grasses, at least 2 feet tall at maturity	9 s.f. per plant
Tree canopy for trees 2.5 inches to 6 inches in diameter	50 s.f. per tree
Tree canopy for trees  6 inches to 12 inches in diameter	250 s.f. per tree
Tree canopy for trees  12 inches to 18 inches in diameter	600 s.f. per tree
Tree canopy for trees 18 inches to 24 inches in diameter	1300 s.f. per tree
Tree canopy for trees larger than 24 inches in diameter	2000 s.f. per tree

3402.8                          Landscape elements of the GAR shall be measured in the following ways:

(a)                All trees shall be measured for diameter at a height four feet, six inches (4 ft. 6 in.) above grade when planted and the square footage equivalent based on diameter shall be as established in the table in § 3402.7;

(b)               For vegetated walls, use the vertical square footage of the portion of the wall covered by vegetation; and

(c)                For all other elements other than trees, large shrubs, perennials, and vegetated walls, square footage is determined by the area of a horizontal plane that is over the element.

3402.9                          Eligible landscape elements are identified in the table below:

 

GREEN AREA RATIO LANDSCAPE ELEMENTS	MULTIPLIER
Landscaped area (select one of the following for each area)
Landscaped areas with a soil depth of less than 24 inches	0.3
Landscaped areas with a soil depth of 24 inches or more	0.6
Bioretention facilities	0.4
Plantings
Ground covers, or other plants less than 2 feet tall at maturity	0.2
Plants , not including grasses, at least 2 feet tall at maturity	0.3
Tree canopy for all trees 2.5 inches to 6 inches in diameter	0.5
Tree canopy for new trees 6 inches in diameter or larger	0.6
Tree canopy for preservation of existing trees 6 inches to 24 inches in diameter	0.7
Tree canopy for preservation of existing trees 24 inches diameter or larger	0.8
Vegetated wall, plantings on a vertical surface	0.6
Vegetated roofs
Extensive vegetated  roof over at least 2 inches but less than 8 inches of growth medium	0.6
Intensive vegetated roof over at least 8 inches of growth medium	0.8
Permeable paving
Permeable paving over at least 6 inches and less than 2 feet of soil or gravel	0.4
Permeable paving over at least 2 feet of soil or gravel	0.5
Other
Enhanced tree growth systems	0.4
Renewable energy generation (area of)	0.5
Water features (using at least 50% recycled water)	0.2
Bonuses
Native plant species listed in §3403.9	0.1
Landscaping in food cultivation	0.1
Harvested stormwater irrigation	0.1

3403                                landscape element conditions for green area ratio

3403.1                          No landscape element may be counted towards a property’s GAR unless it meets the applicable conditions stated in this section.

3403.2                          Plantings over the specified soil depths shall meet the required conditions listed in the Table of Landscape Elements and Multipliers in § 3402.9.

3403.3                          Bioretention facilities shall be landscaped areas that receive rainwater from surrounding areas and use plants and soils to slow, filter, and infiltrate stormwater runoff.  Bioretention facilities include but are not limited to rain or rainwater gardens, bioretention planters, or linear cells or swales.  These do not include structures made of cement or concrete alone.

3403.4                          Trees shall meet the following conditions:

(a)                All trees shall be at least two and one-half inches (2.5 in.) in diameter measured at a height four feet, six inches (4 ft. 6 in.) above grade when planted and shall be replaced if damaged or killed by any cause; and

(b)               All trees shall meet the American Standard for Nursery stock, as set forth by the American Nursery and Landscape Association.

3403.5                          Vegetated walls shall meet the following conditions:

(a)                The maximum calculated vertical dimension shall not exceed thirty feet (30 ft.) unless the vegetated wall features a built-in growth medium;

(b)               The area calculated for the vegetated wall features shall be fully covered within a period of two (2) to five (5) years from planning;

(c)                The area calculated is the ground coverage area, not the total plant growth area;

(d)               The walls shall be at least five feet (5 ft.) from a side or rear lot line; and

(e)                Where stormwater harvesting for irrigation is proposed, vegetated walls shall contain a connection to the proposed irrigation system. 

3403.6                          Vegetated roofs shall meet the following conditions:

(a)                Designs for vegetated roofs must include plans to provide supplemental water;

(b)               Where stormwater harvesting for irrigation is proposed, vegetated roofs shall contain a connection to the proposed irrigation system; and

(c)                The groundcover vegetation on a vegetated roof is not additionally eligible for groundcover value towards GAR requirements. 

3403.7                          Water features shall meet the following conditions:

(a)                Water features must use harvested rainwater for at least fifty percent (50%) of the annual flow; and

(b)               The water features must be under water for at least six (6) months out of twelve (12).

3403.8                           Enhanced tree growth systems shall meet the following conditions:

(a)                Be at least twenty-four inches (24 in.) deep, under pavement, and adjacent to planting areas; and

(b)               Be composed of soils that are not considered contaminated or compacted according to federal SUPERFUND legislation.[1]

3403.9                          Native plant species shall meet the following conditions:

(a)                The plants are listed in the U.S. Fish and Wildlife Service’s Native Plants for Wildlife Conservation Landscaping: Chesapeake Bay Watershed guide; or

(b)               The applicant provides two (2) references in current publications showing that the plant is native to the region; and 

(c)                The plant is not listed on the U.S. Fish and Wildlife Service’s list of Plant Invaders of Mid-Atlantic Natural Areas.

3403.10                      Food cultivation shall meet the following conditions:

(a)                All food cultivation areas must be easily accessible to at least one occupant of the building;

(b)               All food cultivation areas must have a source of water that can reach all portions of the food cultivation area; and 

(c)                The cultivation of animals for food is not eligible for GAR credits.

3403.11                      Harvesting stormwater for irrigation shall meet the following conditions:

(a)                If the irrigation type is spray, applicants shall follow treatment standards set forth in the current District Department of Environment’s Stormwater Management Guidebook; and

(b)               If the irrigation type is drip, no additional treatment of stormwater is required.

3404                                submittal requirements for green area ratio

3404.1                          This section lists the submittal requirements for demonstrating compliance with a GAR requirement.

3404.2                          For the purposes of this section, the term Certified Landscape Expert means a person who is a:

(a)                State of Virginia certified landscape architect;

(b)               State of Maryland certified landscape architect;

(c)                International Society of Arboriculture Certified Arborist;

(d)               Maryland’s certified Professional Horticulturist; or

(e)                Landscape Contractors Association MD-DC-VA Certified Landscape Technician;

3404.3                          Applicants shall submit a GAR score sheet with the GAR calculated for the given lot at the time of building permit application.

3404.4                          Applicants shall provide a landscape plan prepared by a Certified Landscape Expert that includes the following information:

(a)                GAR elements called out by category and area, which may be provided as a part of the landscape plan or as a separate document;

(b)               Lot dimension and size;

(c)                Location and areas of all landscape elements with dimensions;

(d)               Location, size, and species of all plants used to meet requirements;

(e)                Both common and botanical names of all plant material;

(f)                Identification of all existing trees that are to be preserved, with their location, trunk diameter at four feet, six inches (4 ft. 6 in.) above grade, canopy radius, and species;

(g)               Plans indicating how preserved trees and other plants will be protected during demolition and construction;

(h)               Location and dimensions of wheel stops, curbs, or other devices to protect landscaping for landscaped areas adjacent to driveways;

(i)                 A schematic irrigation and drainage plan and the size and depth of all plant containers for rooftop or container landscaping or areas to be irrigated with rainwater;

(j)                 Location and size of any trees to be removed;

(k)               Specifications for soil improvement; and

(l)                 Signature of the Certified Landscape Expert who prepared the plans together as verification that plantings and other landscape elements meet the requirements of the this chapter.

3404.5                          Applicants shall provide a landscape maintenance plan prepared and signed by a Certified Landscape Expert that describes how the plantings, water features and hardscape features will be cared for and maintained including:

(a)                Soil preparation;

(b)               Use of compost;

(c)                Plant replacement;

(d)               Irrigation;

(e)                Weed and pest control; and

(f)                Control of noxious or invasive species.

3404.6                          The following modifications or substitutions to the landscape elements of an approved landscape plan require a plan revision and approval:

(a)                Number of trees, shrubs, or groundcovers;

(b)               Location of required plantings or landscape features;

(c)                Substitution of species; or

(d)               Revisions of any feature that could decrease the planting area or lower the GAR score.

3404.7                          Except as provided below, approved landscape elements shall be installed in accordance with the approved plan prior to the issuance of the certificate of occupancy.

3404.8                          Prior to the issuance of the certificate of occupancy, a landscape checklist must be signed by a Certified Landscape Expert, verifying that that landscaping was installed according to the building permit approved by DCRA.

3404.9                          The Zoning Administrator may grant a temporary certificate of occupancy when installation of the required landscaping is not currently possible due to weather, season or site construction subject to the condition that the required landscaping must be installed within four (4) months after the date the temporary certificate is issued.

3404.10                      The Zoning Administrator may grant up to two (2) extensions of a temporary certificate of occupancy, each for a four (4) month period by based on the same conditions of  § 3004.9.

3405                                SPECIAL EXCEPTIONS FOR GREEN AREA RATIO

3405.1             The Board of Zoning Adjustment may grant, by special exception, a full or partial reduction in the GAR required under this chapter if, in addition to meeting the general requirements of § 3104, the applicant demonstrates that providing the GAR is impractical as a result of equivalent sustainability measures already being implemented on the property that achieve the intent of the GAR through methods not available through the GAR requirement.

3406                                maintenance requirements for green area ratio

3406.1             All plantings and landscape elements used to calculate a property’s GAR must be maintained for the life of the project.  If, for any reason, the installed landscape elements fall below the minimum required GAR score, new eligible landscape elements shall be added to compensate and result in the required ratio. These elements are not required to be the same as the submitted plans, so long as the GAR achieved is equivalent. 

 

All persons desiring to comment on the subject matter of this proposed rulemaking action should file comments in writing no later than thirty (30) days after the date of publication of this notice in the D.C. Register.  Comments should be filed with Sharon S. Schellin, Secretary to the Zoning Commission, Office of Zoning, 441 4^th Street, N.W., Suite 200-S, Washington, D.C. 20001, or electronically per the requirements listed on the Office of Zoning’s website at http://dcoz.dc.gov/services/email.shtm.  Ms. Schellin may also be contacted by telephone at [phone] or by e-mail at [e-mail]. Copies of this proposed rulemaking action may be obtained at cost by writing to the above address.

 

 

 

 

---

[1]               See The Comprehensive Environmental Response, Compensation, and Liability Act of 1980, approved December 11, 1980 (94 Stat. 2767; 42 USC § 9601 et seq.).