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Home My WebLink About12102020 ZPC Agenda Item 3 Page 1 of 6 City of West University Place Zoning and Planning Commission Meeting DATE: December 10, 2020 Agenda Topic: Pervious coverage/materials and open area. Matters related to square-footage, open areas, pervious and impervious coverages, and materials for residential properties. SUMMARY: The City Council has requested that the Planning and Zoning Commission examine the pervious coverages for the City's residential districts. Pervious cover is important as it absorbs rainfall and reduces the amount of water that enters the drainage system. The goal of this agenda item is to examine the City's pervious requirements and determine if any changes are necessary. Exhibit A: Definition of Pervious Pervious area. An area which: (1) is natural ground or landscaped area that receives rainwater and allows it to pass through or be absorbed, thus preventing excess water flow away from the area, or (2) is specifically designated as pervious area in the Projections Schedule. CURRENT PERVIOUS REQUIREMENTS: The City requires a minimum of 24% pervious area within a single-family residential lot. The front yard of homes must have at least 50%pervious coverage, which emphasizes a landscaped streetscape within residential neighborhoods. SURVEY OF RECENT SINGLE-FAMILY HOMES: The City of West University has examples of recently constructed and permitted single-family homes. Generally, the smaller lots have less pervious areas than the larger residential parcels (See table 1). As requested at the October 6, 2020 ZPC Meeting, an additional survey was conducted to add an additional twenty (20) homes to the survey. Table 1: Recent single-family residences pervious coverage Lot Pervious Impervious Address Lot Dim. sq/ft area% Area% Detached Garage 2621 University 50x101 5,050 48 52 Yes 5508 Community 50x116 5,800 44 56 - 5404 Community 50x116 5,800 42 58 - 5304 Community 50x116 5,800 48 52 - 6026 Charlotte 50x91 4,550 45 55 - 2605 Talbott 50x120 6,000 47 53 Yes 3762 Georgetown 60x124 7,440 46 _ 54 - 2616 Fenwood 65x115 7,475 44 56 - 6626 Vanderbilt 100x200 20,000 64 36 - 6630 Vanderbilt 100x200 20,000 57 43 Yes SURVEY ADJACENT CITES: The City of West University Place has a lower than average pervious requirement compared to other adjacent cities in this survey. The most comparable lot Page 2 of 6 City of West University Place Zoning and Planning Commission Meeting regulations for the Old Building Sites in West University Place are found with the City of Bellaire's R-4 District. The Old Building Sites allow for 24%pervious,whereas the comparable R-4 District allows for 40% pervious. For New Building Sites, the most comparable City standards are found with Bellaire's R-3 and Hilshire Villages R-3 Districts. (See Table 2 and Table 3). Table 2: Survey of similar lot sizes in adjacent communities Pervious Requirements-Comparison West University Place (Average lot size per district) * Bellaire Spring Valley Village Hilshire Village SF-1 9867 - - - - - - SF-2 7751 - - - - - - SF-3 6483 - Old Building Sites (SF-1,SF-2,and SF-3) Bellaire-R-4 Minimum Lot Minimum Lot Size 5,000 Size 5,000 - - - 45 or Pervious% 24% Pervious% 40% - -Lot Coverage Impervious Max (7,000 SF Cover 76% or less) 60% - -Lot Coverage Max (More - - - - than 7,000 SF) 55% Residential District Hilshire R-3 New building sites Bellaire-R-3 A District 10,000 SF (Min Minimum Lot Minimum Lot Minimum 9,000 Minimum Size 8,250 Size 7,400 lot size usable) lot size 8,000 Pervious% 24% Pervious% 45% Pervious% 40% Pervious% 45% Impervious Impervious Impervious Impervious Cover 76% Cover 55% Cover 60% Cover 55% *Analysis of mean lot sizes conducted by geographical information systems(GIS)utilizing Harris County Appraisal District Parcel Data. Table 3: Lot Coverage Survey—Detached Residential Districts Page 3 of 6 City of West University Place Zoning and Planning Commission Meeting Maximum Lot Coverage Minimum Maximum Pervious Impervious Maximum Forward Behind Building of Building Building Ground Total Pervious Swimming Pool Line Line Coverage Required Determination Spring Valley Village 50% 60% Water surface is pervious Hilshire Village 50% 55% 40% Impervious 45% (R-1 thru R- Bellaire 3. R-5) and 40% Pervious for R-4 West University 50% 24% Water surface is pervious INNOVATIVE PAVEMENT MATERIALS: Permeable pavers, porous concrete, and other innovative materials are becoming more common place. There is a desire to have paved areas that have less of an impact on the drainage system. These materials are allowed to be considered pervious and not count toward the impervious coverage of the site. GENERAL CLEANUP: A conflict was found within Table-7-5a regarding pavement allowed for single-family residential use. In this case, the use of innovative materials by the Zoning Board of Adjustment by Special Exception. This note is not needed, and can be evaluated during the permit review of a new material. Additionally, if there is a conflict between a material that the Building Official does not believe is durable, his ruling can be appealed to the Zoning Board of Adjustment. Table 7-5a, excerpt pavement and note #4 Pavement Required For SFD use: Hard-surfaced or pervious pavement type required for each required driveway and parking space; See twin "ribbons" of pavement are permitted. For all other Note 4. uses: Reinforced concrete, with curbs and drains required for all vehicular areas. Exceptions: (i) See Table 7-3 (pervious pavement) and Note 4, below. (ii) See Article 10 regarding "overhang." Note 4. Pavement. The ZBA Building Official may issue a special exception to allow other materials if it finds that they will provide equal or better durability. Page 4 of 6 City of West University Place Zoning and Planning Commission Meeting OPEN AREA: When discussing pervious areas, it is also a good practice to bring out open area requirements for residential homes. The ZPC could decide to increase the pervious coverage requirement to 40% of the building site, this modification would mean that the open area and previous coverage requires would be equal. For the most part, any covered area would also be considered impervious. According to the survey conducted by the City of recent homes, the average open area provided is 58%. The proposed redline has been attached, which shows 50% open area requirement for new single-family homes, and a 40%pervious coverage. Exhibit A: Open Area Definition and Table 7-3 Excerpt Open area. Area unoccupied by any structure and open and unobstructed to the sky, except by natural plants or trees, and except for projections specifically permitted by the Projections Schedule, to the extent therein provided. Table 7.3:Open&Pervious General Rule.Eery ouAding see must hare the minimum open and oen.ious areas shown.by Dist CE n tn.s table.('v:4m ns the rule does not appy 1 Ec epneMVSpetal Rules(t)See ODD Areas Schedo es For planned dee'opment distracts.(2)See spec a'.rules noted n table.131 See the Pro)ecl.ore Schedule for dela is aoout calculatng open and pen--sous areas. tem Meas.•e)r'entln • open Me N/A .YOM 5,0 percentage. Rear yard.minnrwm 60k.See NO,r N/A \./A . percentage.See Rote 6 Ent re Du.':d:ng see a0cr 2501 25'+ •5* 1/11111114, Percentage. RECOMMENDATION: The pervious requirement is important for setting limitations for pavement and building coverage on a residential lot. This pervious coverage collectively with all single-family residences increases the runoff of rainwater the community. Staff recommends considering to increase the amount of pervious coverage to 35% or 40% within the SF-1, SF-2, and SF-3 Districts. Table 4: Recommendation Table Proposal Summary of Impact Slight Increase in Pervious to 35% This proposal would allow the majority of porches, pool decking, and single-family developments. Only the most intense projects would be impacted. Moderate Increase in Pervious to 40% This proposal would allow a majority of porches, pool decking and single-family developments. Pool projects or large paving projects may have to consider innovative materials or lessen the amount of impervious coverage. Large Increase in Pervious to 45% This proposal would create a significant of Page 5 of 6 City of West University Place Zoning and Planning Commission Meeting legal-non conforming properties, especially with the smaller more built-out lots. Pool projects or paving projects may have to consider innovative materials or remove existing pavement areas to allocate these materials in areas where the homeowner prefers. Attachments: 1. Redline of proposed changes to the Zoning Ordinance. 2. Survey of recent single-family residential homes with open area. 9/3/2020 West University Place,TX Code of Ordinances Table 7-3:Open&Pervious General Rule:Every building site must have the minimum open and pervious areas shown,by District,in this table.("N/A"means the rule does not apply.) Areas Exceptions/Special Rules:(1)See PDD Schedules for planned development districts.(2)See special rules noted in table.(3)See the Projections Schedule for details about calculating open and pervious areas. Item Measurement SF-1 SF-2 SF-3 TH GR-1 GR-2 C TCC Open area Front yard, 60%. N/A 40% N/A minimum percentage. Rear yard, 60%.See Note 1. N/A N/A N/A minimum percentage.See Note 6. Entire building site, @4O% 25% 25% 15% minimum percentage. Pervious area Front yard, 50% 50%See Note 2. 50%See Note 2. N/A minimum percentage Entire building site, 4N24% 15% 15% 15% 10% minimum percentage. Landscaping strips Required,except for SFD uses on building sites with 5,000 sq.ft.or more.See Notes 3 and 5. Quali°:ed trees For SFD uses on building sites with 5,000 sq.ft.or more,Chapter 82 of the Code of Ordinance must be located within a contiguous and reasonably compact pervious area containing at least 25 sq.ft.However,additional or better pervious area may be required to comply with Chapter 82. Pervious pavement In a QMDS only,pervious pavement is allowed to be used for all vehicular areas,and part of it may count as pervious area.See-Note-4. Parking areas, Each parking area containing 21 or more parking spaces must contain interior pervious areas in"island"or"peninsula"con:igurations aggregating in N/A interior area at least two square feet for each parking space. 1/1 10/5/2020 West University Place,TX Code of Ordinances Table 7-3,cont. General Rule:Every building site must have the minimum open and pervious areas shown,by District,in this table.("N/A" means the rule does not apply.)Exceptions/Special Rules:(1)See PDD Schedules for planned development districts.(2)See special rules noted in table.(3)See the Projections Schedule for details about calculating open and pervious areas. Item Measurement PDD-SF1 PDD-SF2 PDD-TH1 PDD-TH2 PDD-T144 PDD-TH5 PDD-TH7 PDO-C1 Open area Front yard, 60%. N/A N/A minimum percentage. Rear yard, 60%.See Note 1. N/A N/A minimum percentage. See Note 6. Entire 540% 25% N/A building site, minimum percentage. Pervious area Front yard, 50% 50%See Note 2. N/A minimum percentage Entire 4024% 15% N/A building site, minimum percentage Landscaping Required,except for SFD uses on building sites with 5,000 sq.ft.or more.See Notes 3 and 5. strips Qualified For SFD uses on building sites with 5,000 sq.ft.or more,there must be at least one qualified tree in the front yard or in the trees adjacent street area.For all other uses,each qualified tree required by this ordinance or Chapter 82 of the Code of Ordinance must be located within a contiguous and reasonably compact pervious area containing at least 25 sq.ft.However,additional or better pervious area may be required to comply with Chapter 82. Pervious In a QMDS only,pervious pavement is allowed to be used for all vehicular areas,and part of it may count as pervious area.See pavement Note 4. Parking areas, Each parking area containing 21 or more parking spaces must contain interior pervious areas in"island"or"peninsula" interior configurations aggregating in area at least two square feet for each parking space. Table 7-5a: Genera/Rule:Every building site,vehicularareaand related structuremust confomitothe Parking,driveways,etc. applicableregulationsshown,byDistrict,inthistable.("N/A"meanstheruledoesnotapply.) Exceptions/Special Rules:(1)See special rules noted intable.(3)See Article 9 regarding Planned Development Districts.(3)See Note 7 regarding special exceptions.(4)See Article 10. Note 1.Width measurement methods.Minimum driveway width refers to unobstructed vehicular access path and,for non-SFD use,pavement.Maximum driveway width refers to maximum width of pavement in a front yard or street area,excluding complying curb cut aprons.Maximum curb cut width refers to the width of the driveway plus aprons,measured at the edge of the roadway. Note 2.Grouped or shared parking.Article 10 also provides for a special exception,in certain circumstances. Note 3.Parking exclusivity(non-SFD uses).Required parking spaces must be kept open,readily accessible and used for parking only,with no sales,dead storage, display,repair work,dismantling or servicing of any kind.Required guest parking spaces must be kept open and reserved for that use only. Note 4.Pavement.The Z-BABuilding Official may' allow other materials if it finds-that they will provide equal or better durability. West University Place - Pervious/Open Area Coverage Survey Survey Data Remaining Pervious Area Open Area 35% 40% 45% Open Remaining Remainin Address Lot Size Pervious Area %Pervious %Impervious Pervious Pervious pervious Area 40% g at 50% 3747 ALBANS RD 9033 4456 49 51 14 9 4 60.7 20.7 10.7 2908 ROBINHOOD ST 55x105 2449 42.4 57.6 7.4 2.4 -2.6 59 19 9 4120 LEHIGH ST 50x100 2255 45.1 54.9 10.1 5.1 0.1 58.7 18.7 8.7 6319 BUFFALO SPEEDWAY 50x200 5254 53 47 18 13 8 67.6 27.6 17.6 3810 CASE ST 50x114 2542 44.6 55.4 9.6 4.6 -0.4 55.6 15.6 5.6 3782 GEORGETOWN ST 8068 3436 42.6 57.4 7.6 2.6 -2.4 51.3 11.3 1.3 4224 MARQUETTE ST 50x125 4109 45 55 10 5 0 60.6 20.6 10.6 6528 MERCER ST 50x281 6266 44.6 55.4 9.6 4.6 -0.4 71.1 31.1 21.1 3746 TANGLEY ST 60x124 3309 44.4 55.6 9.4 4.4 -0.6 55.2 15.2 5.2 3809 MARQUETTE ST 50x100 2131 43 57 8 3 -2 59.3 19.3 9.3 3501 SUNSET BLVD 50x150 4355 58 42 23 18 13 71.6 31.6 21.6 3009 LAFAYETTE ST 50x100 2184 43.7 56.3 8.7 3.7 -1.3 57.7 17.7 7.7 2814 ALBANS RD 57x105 2741 44 56 9 4 -1 45 5 -5 2922 ALBANS RD 58x105 2590 44 56 9 4 -1 58 18 8 6331 BROMPTON RD 110x150 7506 45.5 54.5 10.5 5.5 0.5 55.2 15.2 5.2 3806 NORTHWESTERN ST 50x120 3635 60.6 39.4 25.6 20.6 15.6 60.6 20.6 10.6 2803 PITTSBURG ST 75x100 3653 48.7 51.3 13.7 8.7 3.7 56.7 16.7 6.7 4229 SOUTHWESTERN ST 50x125 2994 47.9 52.1 12.9 7.9 2.9 65.4 25.4 15.4 6220 COMMUNITY DR 80x100 3811 47.6 52.4 12.6 7.6 2.6 56.3 16.3 6.3 3918 RILEY ST 50x100 2308 46.2 53.8 11.2 6.2 1.2 44.3 4.3 -5.7 2621 University 50x101 5,050 48 52 13 8 3 56.6 16.6 6.6 5508 Community 50x116 5,800 44 56 9 4 -1 66 26 16 5404 Community 50x116 5,800 42 58 7 2 -3 56.3 16.3 6.3 6026 Charlotte 50x91 4,550 45 55 10 5 0 58.4 18.4 8.4 3762 Georgetown 60x124 7,440 46 54 11 6 1 51.3 11.3 1.3 2616 Fenwood 65x115 7,475 44 56 9 4 -1 59.2 19.2 9.2 6630 Vanderbilt 100x200 20,000 57 43 22 17 12 60.8 20.8 10.8 Averages 58.46296 18.462963 8.462963