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HomeMy WebLinkAboutItem 5.1 - SupplementalGODBE RESEARCH Gain Insight HOUSING REGULATIONS COMMUNITY SURVEY Presented to the Town of Los Altos Hills April 27, 2007 Los Altos Hills: Housing Regulations Community Survey Table of Contents Overview and Research Objectives 2 Methodology Overview 3 Key Findings 4 • Site Development Issues 4 • Grading Limitations 16 • Average Size of Home 17 • Required Setbacks t6 • Development Review Process 20 • Dedication of Open Space Easements 25 • Property Line Fences 26 • Outdoor Lighting 26 Conclusions 30 Additional Respondent Information 32 • Length of Residence 32 Age 33 • EMnicity, 34 Gentler 35 Appendix A: Methodology 36 Appendix B: Topline Report 42 Appendix C: Crosstabulation Tables 43 Appendix D: Questionnaire 44 Godbe Research— Page i April 27, 2007 Los Altos Hills: Housing Regulations Community Survey The Town of Los Altos Hills commissioned Godbe Research to conduct a survey of adult residents in the community to assess the residents' opinions and altitudes on specific housing regulations. The Research Objectives for this study are: • Ascertain whether certain housing regulations were too restrictive, loo permissive, or just right; • Assess support or opposition to increasing the minimum allowable Floor area and development area; • Gauge public opinion on the current regulations regarding required setbacks; • Measure happiness with the current development review process; and. • Test ordinances and regulations regarding property fence lines and outdoor lighting. This report begins with a Methodology Overview introducing the sampling and data collection techniques used in this study. The Key Findings section offers a question -by -question analysis of the survey including: • Site Development Issues Grading Limitations Average Size of Home Required Setbacks Development Review Process Open Space Easements Property Line Fences Outdoor Lighting The Conclusions section summarizes the key results of the study. Appendix A explains the Detailed Methodology used In the stutly. Appendix B provides the Topline Report with overall survey results. Appendix C presents the complete Crosstabulation Tables. Appendix D presents the complete Questionnaire used for the study. GndbeRoseaah - Page 2 April 27. 200] Los Altos Hills: Housing Regulations Community Survey Survey Methodologv A total of 300 respondents completed the survey, representing a total universe of approximately 6,041 adult residents of Los Altos Hills, producing a margin of error of plus or minus 5.5 percent. Interviews were conducted from March 20 through March 28, 2007, and each interview typically lasted 13 minutes. Sample 8 Weighting Once collected, the data were compared with the total adult population of Los Altos Hills to examine possible differences between the sample of respondents and the actual universe. After examining the details, the data were weighted to the actual proportions of the residents by their age and ethnicity. Randomization of Questions To avoid the problem of systematic position bias -where the order in which a sense of questions is asked could systematically influence the answers - several questions in this survey were randomized such that respondents were not consistently asked the questions in the same order. The series of items in Questions 2, 3, 12, 14, and 16 were randomized to avoid such systematic position bias. Ggdbe Research -Pa 3 Annl 27, 200] Los Altos Hills: Housing Regulations Community Survey The first substanlivu question of the survey asked whether certain development regulations were too restrictive, too pemrissive, or just right. In general, the majority of respondents felt all four regulations tested were just right. However, when looking at the net difference between those respondents stating a regulation was too restrictive versus too permissive, some key findings emerged. Approximately one in five (22 percent) additional respondents felt "Required yard setbacks for Front yards are 40 feet fmm the property line" was too restrictive (27 percent) versus too permissive (5 percent). The net difference between those respondents that felt "Required yard setbacks for side and rear yards are 30 feel from the property line" is too restrictive and those that thought the regulation is too permissive, was 19 percent (26 percent, too restrictive vs. 7 percent, too permissive). Regulations such as "The owner of a one -acre, flat lot is currently allowed to build 6,000 square feet of floor area" and "The owner of a one -acre, flat lot is currently allowed to build 15,000 square feet of development area" had smaller net differences of those respondents that stated the regulation utas too restrictive and those that stated it was too permissive. In general, regulations regarding required setbacks had the largest proportion of residents that stated the regulation was just right, while also displaying the highest ratio between those respondents that said the setback regulation was too restrictive versus too permissive. Godbe Research —Page 4 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey The next two pages show the results of the site development questions by the residents' length of residence. As shown in the above table, a higher proportion those residents having lived in Los Altos Hills for 15 years or less, felt "The owner of a one -acre, flat lot is currently allowed to build 6,000 square feet of floor area" was too restrictive when compared to those residents of 16 or more years. A similar finding can be seen with the regulation: "The owner of a one -acre, flat lot is currently allowed to build 15,000 square feet of development area." Albeit, the difference between those residents having lived in Los Altos Hills 15 years and under and those that have lived in the community for over 15 years, is to a lesser degree. It should be noted that the majority of responses were "Just right" when looking at most subsegments. It should also be noted that readers should use extreme caution in generalizing results where the number of responses in a category is below 25 completed interviews. Site Development Regulations 2A. The owner of a one -acre, flat lot is currently allowed to build 6,000 square feel of "floor area" otherwise known as "building square footage" or "house foot print" 2B. The owner of a one -acre, flat lot is currently allowed to build 15,000 square feel of "development area" which is floor area plus other paved surfaces such as driveways, pools, etc... 2C. Required yard setbacks for front yards are 40 feet from the property line 2D. Required yard setbacks for side and rear yards are 30 feel from the property line Godbe Research - Page 5 Aphi 2007 Los Altos Hills: Housing Regulations Community Survey A greater proportion of respondents who have lived in Los Altos Hills five years or fewer felt the required setback regulations were "too restrictive" than did residents in other subsegments. Their differences are statistically significant at the 95 percent confidence interval when comparing results against the residents that have lived in Los Altos Hills more than 20 years. Site Development Regulations 2A. The owner of a one -acre, flat lot is currently allowed to build 6,000 square feet of "floor area" otherwise known as 'building square footage" or "house foot print" 2B. The owner of a one -acre, flat lot is currently allowed to build 15,000 square feet of "development area" which is floor area plus other paved surfaces such as driveways, pools, etc... 2C. Required yard setbacks for front yards are 40 feet from the property line 2D. Required yard setbacks for side and rear yards are 30 feet from the property line Godbe Rec..h - Page 6 APM 21, 207 Los Altos Hills: Housing Regulations Community Survey The above table displays results of 2A and 2B by specific age categories. The major significant difference found in this table is that a higher proportion of residents aged 40 to 49 fell these two regulations were too restrictive (36 percent, 2A and 40 percent, 213) than did residents aged 70 or older (9 percent, 2A and 6 percent, 213). Site Development Regulations 2A. The owner of a one -acre, flat lot is currently allowed to build 6,000 square feel of'Toor area' otherwise known as "building square footage" or 'house foot print" 2B. The owner of a one -acre, flat lot is currently allowed to build 15,000 square feet of 'development area' which is floor area plus other paved surfaces such as driveways, pools, etc... 2C. Required yard setbacks for front yards are 40 feel from the property line 2D. Required yard setbacks for side and rear yards are 30 feet from the property line Godbe Research - Page 7 Ap6127, 2007 Los Altos Hills: Housing Regulations Community Survey n Br m n s1 4z ,s M71 110% 17 r 1)0% 183% .'s h5.0% is 1% ],.p% 642% 78b% lB1% BS)L uw. 00% oa% Be% ?8% i 51% ].1% aox I pox � +sx sx j ao% The above table displays results of 2C and 2D by specific age categories. A higher proportion of residents aged 30 to 39 fell "Required yard setbacks for front yards are 40 feet from the property line" (47 percent) was too restrictive than did residents aged 70 or older (15%). Furthermore, residents aged 30 to 39 are more likely to have felt "Required yard setbacks for side and rear yards are 30 feel from the property line" (45 percent) was too restrictive than residents aged 60 to 69 (13 percent). Site Development Regulations 2A. The owner of a one -acre, flat lot is currently allowed to build 6,000 square feel of "floor area" otherwise known as "building square footage" or "house fool print" 2B. The owner of a one -acre, flat lot is currently allowed to build 15,000 square feet of "development area' which is Floor area plus other paved surfaces such as driveways, pools, etc... 2C. Required yard setbacks for front yards, are 40 feet from the property line 2D. Required yard setbacks for side and rear yards are 30 feet from the property line Godbe Research — Page 8 April 27. 2007 y 65 77 11 a] 11 M71 110% 17 r 1)0% 183% .'s ]6 B3 656'Y. 84.9% 73 G% 429% —i 16.P% 12% ?8% i 51% ].1% The above table displays results of 2C and 2D by specific age categories. A higher proportion of residents aged 30 to 39 fell "Required yard setbacks for front yards are 40 feet from the property line" (47 percent) was too restrictive than did residents aged 70 or older (15%). Furthermore, residents aged 30 to 39 are more likely to have felt "Required yard setbacks for side and rear yards are 30 feel from the property line" (45 percent) was too restrictive than residents aged 60 to 69 (13 percent). Site Development Regulations 2A. The owner of a one -acre, flat lot is currently allowed to build 6,000 square feel of "floor area" otherwise known as "building square footage" or "house fool print" 2B. The owner of a one -acre, flat lot is currently allowed to build 15,000 square feet of "development area' which is Floor area plus other paved surfaces such as driveways, pools, etc... 2C. Required yard setbacks for front yards, are 40 feet from the property line 2D. Required yard setbacks for side and rear yards are 30 feet from the property line Godbe Research — Page 8 April 27. 2007 Los Altos Hills: Housing Regulations Community Survey 3. The Lot Lot Facroq or WF, Is a formula he cakulale Me allowable floor and de, onresidential fees and Is based on total acreage and supe maracienn sn1 For properties with a wr of sl lent 0.50 Monaample, a t acre lot with 30' minimum allowable floor area Is 6,000 sq. n. and Me minimum allowable on, 7.500 sq. a. Do you hall lM.Iatee antro a, We palmlaslve, Minimum all d—romi 7300 guar aoara eaR When asked their opinion of the minimum allowable development area of 7,500 square feet, 41 percent of residents fell it was "Just right," 34 percent said it was "Too restrictive," and 15 percent felt is was "Too permissive." Nine percent declined to provide an opinion to this question. Similar results were seen with the minimum allowable Floor area of 5,000 square feet. Fifty -ane percent of residents felt this regulation was "Just right," 31 percent "Too restrictive," and 12 percent "Too permissive ."Just under seven percent of residents declined to state or did not know. Godbe Research- Paye 9 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey A similar finding is exposed when looking at these results by the respondent's length of residence in Los Altos Hills. Residents having lived in Los Altos Hills 15 years or less have markedly different opinions than those residents that have lived in Los Altos Hills 16 or more years. More recent residents of Los Altos Hills are more likely to feel that the minimum allowable floor area of 5,000 square feel and minimum allowable development area of 7,500 are too restrictive than more established residents. Site Development Regulations 3A. Minimum allowable floor area of 5,000 sq ft 3B. Minimum allowable development area of 7,500 square feet Godbe Research —Page 10 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey O b 65 77 51 12 15 HO% S6A% 1011 b0% 111% 190% 1111 iE11 905% 505% 4111% 5111, 91% 71% 2201 69% 561 911 1511 110% 71% 00% 22% 51, 551 961 148% 711 11 65 77 11 11 15 6251 .11 41 2171 12.0% 1591 2621 m]% 111% 1021 11110 500% 159% 1161 11 3% 1791 221% w% 22% a1% 9A% 1011 261% 149I When looking at results by various age categories, half of the residents aged 30 to 39 years felt the minimum allowable floor area of 5,000 square feet and minimum allowable development area of 7,500 square feet was "Too restrictive." Site Development Regulations 3A. Minimum allowable floor area of 5,000 sq ft 3B. Minimum allowable development area of 7,500 square feet Godbe Research - Page i 1 April 27, 207 Los Altos Hills: Housing Regulations Community Survey When asked if the allowable size of a house should be reduced as the low becomes steeper, 60 percent of residents replied 'Yee while 34 percent replied "No." Seven percent of Los Altos Hills residents did not offer an opinion to this question. Genes Research —Page 12 Apol27, 2007 Los Altos Hills: Housing Regulations Community Survey When asked if the minimum allowable floor area be increased from 5,000 square feet to closer to 6,000 square feet for all one -acre lots, regardless of the slope on Ne property, 55 percent replied "No" and 41 percent said "Yes." Just under five percent of respondents had no opinion. Godbe Research—Page 13 Apn127, 2007 Los Altos Hills: Housing Regulations Community Survey When asked if the minimum allowable development area be increased from 7,500 square feet to closer to 8,500 square feet for all one -acre lots, regardless of the slope on the property, 58 percent replied "No" and 39 percent said "Yes." Four percent of respondents had no opinion. Godbs Research - Page 16 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey The above table compares respondents answers to a potential increase in the minimum allowable floor area and development area. Eighty percent of those respondents that replied 'Yes' to the increase in the minimum allowable floor area, also said "Yes" to the increase in the minimum allowable development area. Conversely, 88 percent of those residents that replied 'No' to the increase m the minimum allowable floor area, also said "No" to the increase in the minimum allowable development area. Thus, only a small portion of respondents held differing opinions in a potential increase in the minimum allowable floor and development areas and showed consistency in the two questions. Godbe Research - Page 15 April 2l, 2007 Los Altos Hills: Housing Regulations Community Survey The next question of the survey read: To encourage construction that follows the natural slopes and blends with the natural contour of the land, the Town's grading policy requires that grading levels and retaining walls do not generally exceed 3 feet of cut or excavated earth and 4 feel of fill or deposited earth. Individual sites may dictate a need to deviate from the criteria but would require Planning Commission and/or City Council approval. Do you feel that the grading limitations are: Too restnctive, Just right, Too permissive? Fifty-one percent of Los Altos Hills residents replied that grading limitations were 'Just right," while 36 percent felt they were 'Too restrictive" and seven percent Too permissive" Five percent of respondents didn't know or declined to provide an opinion on this question. Godbe Research - Page 16 Apn12].200] Los Altos Hills: Housing Regulations Community Survey Respondents were next asked: In the last ten years, the average size of a typical new single-family house built in Los Altos Hills is 6,700 sq. ft. The Town has also seen the construction of some new single-family homes in the range of 10,000-25,000 sq. ft. The homes are sometimes referred to as estate homes. The maximum allowable size of a home is proportional to the size of the lot and the slope (for example a 1 acre flat lot is allowed up to 6,000 sq. ft. of floor area and a 5 acre flat lot is allowed up to 30,000 sq. ft. of floor area). Should Los Altos Hills consider imposing a cap or a limit on the absolute maximum size of a home? (GET YES/NO ANSWER FIRST, THEN ASK IF YES) What should that limit be? Most (42 percent) respondents replied that there should not be a limit imposed on the absolute maximum size of a home. Thirty-six percent of respondents felt a 10,000 to 15,000 square feet limit was appropriate. Nine percent felt the limit should be between 15,000 and 20,000 square feet and just over six percent felt the limit should be somewhere between 20,000 and 30,000 square feet. Six percent of respondents did not know or declined to provide an opinion. Godi Research—Page 17 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey When asked if the required setbacks be increased for estate homes, the vast majority of respondents replied "Yes" (72%). One-quarter of residents replied "No" (25 percent) and only three percent did not have an opinion on this question. Gonna Research - Page 18 April 27. 2007 Los Altos Hills: Housing Regulations Community Survey Those respondents that felt required setbacks sound be increased for estate homes were asked to what sized home the restrictions should be applied. Forty percent of respondents replied the increased setback restrictions should be applied to homes over 8,000 square feel, another 35 percent replied homes over 10,000 square feet should be subject, and 16 percent mentioned homes over 12,000 square feet. Three percent of respondents provided some square footage home over 12,000 and six percent did not know or declined to provide an answer to this question. Two hundred and fifteen residents replied to this question. Godhe Research — Page 19 Apn121, 2001 Los Altos Hills: Housing Regulations Community Survey Respondents were next asked if they were happy with the current development review process. Nearly six in ten (59 percent) replied "Yes," 31 percent replied "No" and 10 percent did not know or did not provide a response to this question. Godbe Reseemh—Pop 20 Apn127, 2007 Los Altos Hills: Housing Regulations Community Survey As shown in the above table, fifty-five percent of those residents that have moved to Los Altos Hills within the past five years were not happy with the current development review process. Residents of other subgroups were fairly consistent in their answer to this question. Godbe Research—Page 21 Apnl21, M07 Los Altos Hills: Housing Regulations Community Survey When looking at whether residents were happy with the current development review process by age categories, some noticeable differences can be seen. As shown in the above table, two-thirds (66 percent) of residents aged 18 to 29 were not happy with the development review process. Thirty-seven percent of residents aged 30 to 39 replied they do not know. And finally, 84 percent of reeidents aged 70 or older replied that they were happy with the current development review process. In general, the older the resident, the more likely they were to say "Yes," that they were happy with the process. Godbe Research —Page 22 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey The next question in the survey exposed residents to three distinct opinions and asked which one, in particular, was the closest match to their own. The question was read as follows: Please tell me which of the following three statements is closest to your own opinion. Hem's the first/second/third one . A. The Planning Commission andlor Town staff should continue to conduct site development review to determine compliance with Town development policies and standards, and provide for public input. (This would continue the current procedure.) B. The Town should establish an Architectural Review Board, made up of design professionals, to conduct home design review, including provisions for public input. C. The current system of discretionary review should be replaced by a process that simply requires compliance with quantified development standards. Projects that do not meet the standards would continue to be referred to the Planning Commission for review. No clear cut winner emerged as opinions A and C garnered the same reply of 36 percent. Twenty- three percent of residents felt opinion B was closest to their own. Godbe Research - Page 23 AP1127,2007 Los Altos Hills: Housing Regulations Community Survey Not surprisingly, 51 percent of those respondents that earlier in the survey stated They were happy with the current development review process felt opinion A (essentially the option that would continue the current procedure) was closest to their own. Fifty-eight percent of those respondents that were not happy with the current process sided with option C, "The current system of discretionary review should be replaced by a process that simply requires compliance with quantified development standards. Projects that do not meet the standards would continue to be referred to the Planning Commission for review" GWbe Research —Page 24 Apn127,2007 Los Altos Hills: Housing Regulations Community Survey Respondents were next asked The Town sometimes requires the dedication of open space easements on private property with slopes of 30% or more at the time of new development. This is intended to protect areas of steep slopes, creeks, or significant stands of oak trees from disturbance. Do you agree or disagree with this policy? Seven in ten Los Altos Hills residents agreed with this policy (44 percent strongly agree and 28 percent somewhat agree). Approximately one-quarter of residents disagreed with the policy and three percent replied "Dant know" Godbe Research - Page 25 APn127, 207 Los Altos Hills: Housing Regulations Community Survey The next series of questions addressed the issue of property line fences and the regulations that pertain to them. Respondents were presented three potential fence limitations and asked whether they would support such changes. Two-thirds (67 percent) of residents would not be in favor of reducing the allowable height of property line fences to below six feet. Fifty-eight percent would not be in favor of limiting perimeter fencing to a percentage of the overall area of the parcel and 57 percent are not in favor of limiting the fencing material to require open fences. 6odbe Research - Page 26 Al 2007 Los Altos Hills: Housing Regulations Community Survey When asked if the fence ordinance should be amended to allow open deer fencing (fences taller than 6 feet), nearly half (49 percent) replied "Yes" and 45 percent replied "No." Six percent of residents replied don't know or did not have an opinion on this matter. Godbe Research - Page 27 Acnl 27, 207 Los Altos Hills: Housing Regulations Community Survey With the next question in the survey, residents of Los Altos Hills were asked about their level of agreement or disagreement with specific outdoor lighting statements. Responses have been recoded to better display results in the form of can scores. Responses have been recoded into the following: "Strongly agree' =+2, "Somewhat agree" _ +1, `Somewhat disagree" _ -1, "Strongly disagree" =-2. Thus, a score of 1.0 means, in general, respondents somewhat agree with that particular statement regarding outdoor lighting. In general, residents somewhat agreed that "Outdoor lighting on private property should be regulated to control outdoor light impacts to surrounding properties and to control the potential for light pollution or skyglow" and "Outdoor lighting should be allowed to accent buildings and landscaping, provided that glare on neighbors is minimized." Overall, residents somewhat disagreed that "Outdoor lighting should not be regulated.' Godbe Research - Page 28 April 27. 2007 Los Altos Hills: Housing Regulations Community Survey The above table displays results by age subgroups. Residents aged 18 to 29 tend to have slightly higher agreement levels with "Outdoor lighting on private properly should be regulated to control outdoor light impacts to sumounding properties and to control the potential for light pollution or skyglow" and, in general, neither agreed nor disagreed with "Outdoor lighting should be allowed to accent buildings and landscaping, provided that glare on neighbors is minimized." Residents aged 3010 39, displayed a high level of disagreement with "Outdoor lighting should not be regulated." Godbe Research - Page 29 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey Site Development Issues When asked if specific site development regulations were loo restrictive, too permissive, or just right, the majority of residents stated they were just nght - a signal that current regulations should be maintained as is. However, of those that indicated a change is needed (fell the regulation was either too restrictive or permissive), a higher proportion of residents stated the regulations were too restrictive, rather than too permissive. This was especially evident with "Required yard setbacks for front yards are 40 feet from the property line" where the ratio of those residents that felt the requirement was too restrictive versus loo permissive, was five to one. Housing Size Limitations Questions regarding the absolute size of a house in Los Altos Hills received mixed responses. Four in ten residents telt there should not be any limit as the size of a home. Approximately had of the residents did express a desire for a limit, and of those residents, most felt houses should be no greater than 15,000 square feet. Development Review Process Although six in ten residents were "happy" with the current development review process, when presented with three review process options, only 36 percent favored the current process. Of the three options, not one received an overwhelming percentage of support. However, the option "The Town should establish an Architectural Review Board made up of design professionals, to conduct home design review, including provisions for public input' lagged behind the option to maintain the current procedure and the option "The current system of discretionary review should be replaced by a process that simply requires compliance with quantified development standards. Projects that do not meet the standards would continue to be referred to the Planning Commission for review." Godbe Research - Page 30 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey Open Space Easements Residents had very strong agreement with the policy regarding open space easements - the dedication of open space easements on private property with slopes of 30% or more at the time of new development. Property Fence Lines Most residents of Los Altos Hills are not in favor of additional regulations revolving around property line fencing including reducing the allowable height of property line fences to below six feet, limiting perimeter fencing to a percentage of the overall area of the parcel, and limiting the fencing material to require open fences Outdoor Lighting In terms of outdoor lighting, most residents supported various regulations. Residents somewhat disagreed that outdoor lighting should not be regulated. Furthermore, residents, in general, somewhat agreed that "Outdoor lighting on private property, should be regulated to control outdoor light impacts to surrounding properties and to control the potential for light pollution or skyglow" and "Outdoor lighting should be allowed to accent buildings and landscaping, provided that glare on neighbors is minimized." Differences in Key Subgroups When looking at results by certain subgroups, mainly age categories and length of residence, significant differences in opinion arise. In general, those residents having recently moved to Los Altos Hills (residents of under 15 years) are more likely to feel certain regulations are too restrictive. Furthermore, younger residents (residents in their 20's, 30's, and 40's) also are more likely to say a particular regulation is too restrictive. The important question this finding raises is, WIN the younger and more recently established residents maintain their opinions over the next 10 to 20 years, or are the feelings that development and other housing regulations are too restrictive a universal opinion of that demographic and one that could potentially change in the future. Godbe Research - Page 31 ApM 2l, 200] Los Altos Hills: Housing Regulations Community Survey The remaining slides review the demographic questions asked within the survey. Residents' length of residence was asked at the beginning of the survey and served as a warm-up question as well as a question used for segmentation purposes. Age, ethnicity, and gender were all asked at the end of the survey and helped ensure there was a representative sample of survey responses collected. All demographic questions were optional and respondents had the choice of not answering them. Godbe Research - Page 32 April 27, 207 Los Altos Hills: Housing Regulations Community Survey Gtlbe Research — Page 33 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey Go be Reseamh-Page 34 ApM 27, 200] Los Altos Hills: Housing Regulations Community Survey Godbe Re eaxh - Page 35 Apnl 27. 2007 Los Altos Hills: Housing Regulations Community Survey Margin of Edor Because a survey typically involves a limited number of people who are part of a larger population group, by mere chance alone there will almost always be some differences between a sample and the population from which it was drawn. These differences are known as "sampling enrol' and they are expected to occur regardless of how scientifically the sample has been selected. The advantage of a scientific sample is that we are able to calculate the sampling error. Sampling error is determined by four factors: the population size, the sample size, a confidence level, and the dispersion of responses. The table above shows the possible sampling variafon that applies to a percentage result reported from a probability type sample. Because a sample of 300 respondents is drawn from the estimated population of approximately 6,000 adult residents in the Town of Los Altos Hills, one can be 95 percent confident that the margin of error due to sampling will not vary, plus or minus, by more than the indicated number of percentage points from the result that would have been obtained K the interviews had been conducted with all persons in the universe. As the table indicates, the maximum margin of error for all aggregate responses is between 3.3 and 5.5 percent for the survey. This means that, for a given question with dichotomous response options (e.g., Yes/No) answered by all 300 respondents, one can be 95 percent confident that the difference between the percentage breakdowns of the sample population and those of the total population is no greater than 5.5 percent. The percentage margin of error applies to both sides of the answer, so that for a question in which 50 percent of respondents said yes, one can be 95 percent confident that the actual percentage of the population that would say yes is between 44.5 (50 minus 5.5) percent and 55.5 (50 plus 5.5) percent. Godbe Research - Page 36 April 27, 2007 Los Altos Hills: Housing Regulations Community Survey The margin of error for a given question also depends on the distribution of responses to the question. The 5.5 percent refers to dichotomous questions where opinions are evenly split in the sample with 50 percent of respondents saying yes and 50 percent saying no. If that same question were to receive a response in which 10 percent of the respondents say yes and 90 percent say no, then the margin of error would be no greater than 3.3 percent. As the number of respondents in a particular subgroup (e.g., age) is smaller than the number of total respondents, the margin of error associated with estimating a given subgroup's response will be higher. Due to the high margin of error, Godbe Research cautions against generalizing the results for subgroups that are composed of 25 or fewer respondents. Godbe Research - Page 3 AVnl2), 2007 Los Altos Hills: Housing Regulations Community Survey How to Read Crosslabulation T The questions discussed and analyzed in this report comprise a subset of various crosstabulation tables available for each question. Only those subgroups that are of particular interest or that illustrate particular insights are included in the discussion. Should readers wish to conduct a closer analysis of subgroups for a given question, the complete breakdowns appear in Appendix C. These crosstabulation tables provide detailed information on the responses to each question by all demographic groups that were assessed in the survey. A typical crosslabulation table is pictured above. A short description of the item appears on the left-hand side of the table. The sample size (in this case n = 300) is presented in the first column of data under "Total." The results to each possible answer choice of all respondents are presented in the first column of data under 'Total." The aggregate number of respondents in each answer category is presented as a whole number, and the percentage of the entire sample that this number represents is just below the whole number. For example, among the total respondents, 178 residents stated that the allowable size of a house should be reduced as the lot becomes steeper and this number of respondents equals to 60 percent of the total sample size of 300. Next to the "Total' column are other columns representing responses from male and female respondents. The data from these columns are read in exactly the same fashion as the data in the "Total" column, although each group makes up a smaller percentage of the entire sample. Godbe Research - Page 38 Apri127 2007 Los Altos Hills: Housing Regulations Community Survey Subgroup Comparisons To test whether or not the differences found in percentage results among subgroups are likely due to actual differences in opinions or behaviors -rather than the results of chance due to the random nature of the sampling design- a "z -test" was performed. In the headings of each column are labels, 'A," 'B," etc. along with a description of the variable. The "z -test" is performed by comparing the percentage in each call with all other cells in the same now within a given variable (within gender in the pictured table, for example). The results from the "z -test' are displayed in a separate table below the crosstabulation table. If the percentage in one cell is statistically different from the percentage in another, the column label will be displayed in the cell from which it varies significantly. For instance, in the table above, if a significantly higher percentage of women (11%) had mentioned that they "Didn't know" whether the allowable size of a house should be reduced as the lot size becomes steeper than the percentage of men (3%), the alphabet "A," which stands for "male respondents" appears under Column "B"which stands for'female respondents." The letters in the table indicate for which differences one can be 95 percent confident that the results are due to actual differences in opinions or behaviors reported by subgroups of respondents. It is important to note that the percentage difference among subgroups is just one piece in the equation to determine whether or not two percentages are significantly different from each other. The variance associated with each data point is integral to determining significance. Therefore, two calculations may be different from each other according to the percentage reported, yet the difference may not be statistically significant according to the Y' statistic. Godbe Research - Page 39 April 27, 207 Los Altos Hills: Housing Regulations Community Survey Understanding a "Mean" In addition to the analysis of response percentages, many results will be discussed with respect to a descriptive "mean." "Means" are effectively "averages." To derive a respondent's overall agreement with an outdoor lighting statement (Qi 6), for example, a number value is first assigned to each response category (e.g., "Strongly agree" =+2, "Somewhat agree" =+1, "Somewhat disagree" =+1, and "Strongly disagree" =+2). The answer of each respondent is then assigned the corresponding number (from +2 to -2 in this example). Finally, all the respondents' answers are averaged to produce a final number that reflects average interest. The resulting mean makes interpretation of the data considerably easier. In tables and charts for Question 16 of the survey, the reader will find mean scores that represent answers given by the respondents. The mean score represents the average response of each group. The table above shows the scales for each corresponding question. Responses of "DK/NK were not included w calculating the means for any question. Godbe Research - Page 40 April 2l, 2007 Los Altos Hills: Housing Regulations Community Survey Only those subgroups that are of particular interest or that illustrate a particular insight are included in the discussion within the report with regard to mean scores. A typical crosetabulalion table displaying mean scores is shown in the pictured table. The aggregate mean score for each item in the question series is presented in the first column of the data under "Total." For example, among all the survey respondents, the outdoor lighting statement, "Outdoor lighting on private property should be regulated to control outdoor light impacts to surrounding properties and to control the potential for light pollution or skygli was assigned a mean score of 1.0. Next to the "Total" column are other columns representing the mean scores assigned by the respondents grouped by gender. The data from these columns are read in the same fashion as the data in the "Total' column. To test where two mean scores are statistically different, a't-test" is performed. As in the case of the "z -test" for percentages, a statistically significant result is indicated by the alphabet representing the data column. Godbe Research - Page 41 Apnl2],200] Los Altos Hills: Housing Regulations Community Survey The following appendix displays the topline report, which include the percentage of 300 respondents who reported the items in the answer options to each of the questions in the survey (unless a skip pattern is indicated). For example, if 50 percent is next to the "Yes" response option for a question, then about 150 respondents indicated a "Yes" answer to that question. Godbe Research - Page 42 Apd127,2007 Los Altos Hills: Housing Regulations Community Survey The following appendix displays the crosstabulation tables should readers wish to conduct a closer analysis of subgroups for a given question. These crosstabulalion tables provide detailed information on the responses to each question by all demographic groups that were assessed in the survey. Godbe Research Apri12, 2007 Los Altos Hills: Housing Regulations Community Survey The following appendix displays the questionnaire that was used for collecting the data of the study. God6e Research April 21, 207