Site Attributes: Size, Shape, and Special Features

Chapter Title: Site Attributes: Size, Shape, and Special Features

Introduction:

The intrinsic characteristics of a site profoundly influence its value, utility, and suitability for specific uses. This chapter delves into three key site attributes – size, shape, and special features – exploring their scientific underpinnings, practical implications, and impact on real estate valuation. Understanding these attributes is paramount for accurate site analysis and informed decision-making in real estate.

1. Site Size

Site size is a fundamental attribute directly impacting development potential and value. The relationship between size and value is not always linear and is often subject to economies of scale and market demand.

1. Area Measurement and Units:
   • Accurate measurement of site area is crucial. Common units include square feet (sq ft), acres (ac), hectares (ha), and square meters❓ (m²).
   • Conversion formulas:
     • 1 acre = 43,560 sq ft
     • 1 hectare = 10,000 m² ≈ 2.47 acres
2. Economies of Scale:
   • Generally, as site size increases, the unit price (e.g., price per sq ft or price per acre) decreases due to economies of scale. This reflects reduced infrastructure costs per unit, bulk discounts on materials, and other efficiencies.
   • Conversely, smaller sites often command higher unit prices due to scarcity and increased demand for specific uses.
3. Functional Utility and Ideal Size:
   • Different land uses have ideal size requirements. Residential developments may require specific lot sizes based on zoning regulations and desired density. Commercial or industrial uses often necessitate larger sites to accommodate buildings, parking, and other operational needs.
   • The concept of “functional utility” refers to the site’s ability to effectively support its intended use. Sites that are too small or too large may suffer from reduced functional utility.
4. Excess Land and Surplus Land
   • A given land use has an optimum parcel size, configuration, and land-to-building ratio. Any extra or remaining land not needed to support the specific use may have a different value than the land area needed to support that use.
   • Excess land can be sold off separately from the rest of the property so that the subject property in effect becomes two or more properties. Excess land must be addressed in the highest and best use analysis.
   • Surplus land cannot be sold off separately and does not have an independent highest and best use.
5. Practical Applications and Examples:
   • Residential Development: Analyze sales data of residential lots of varying sizes to identify trends in price per square foot and optimal lot sizes for specific housing types (e.g., single-family homes, townhouses, apartments).
   • Commercial Development: Determine the minimum site size required for a proposed retail store, office building, or shopping center based on building footprint, parking ratios, and zoning requirements.
   • Industrial Development: Assess the land-to-building ratio and site area needed for a manufacturing plant or warehouse facility, considering storage requirements, loading docks, and truck access.
6. Related Experiments:

   • Regression Analysis: Conduct a regression analysis of sales prices versus site sizes in a specific market area to quantify the relationship between size and value. The regression equation might take the form:

     • Selling Price = β0 + β1 * Site Size + ε, where:
     • β0 is the intercept (base price)
     • β1 is the coefficient representing the change in selling price for each unit increase in site size.
     • ε is the error term.
     • The coefficient β1 helps determine the marginal value of additional land area.

2. Site Shape

Site shape significantly affects its usability, layout efficiency, and development potential. Irregularly shaped sites may present challenges but can also offer unique opportunities for creative design.

1. Shape Metrics and Classification:
   • Quantifying site shape involves various metrics, including:
     • Perimeter-to-Area Ratio: A higher ratio indicates a more irregular shape. Calculated as Perimeter / Area.
     • Shape Index (SI): Compares the site’s perimeter to the perimeter of a circle with the same area. SI = Perimeter / (2 * √(π * Area)). A value of 1 represents a perfect circle.
     • Compactness Ratio: Measures the ratio of the area of the site to the area of a circle with the same perimeter.
   • Common shape classifications include rectangular, square, triangular, trapezoidal, irregular, and flag lot.
2. Frontage and Depth:
   • Frontage is the length of the site that abuts a street, river, or other prominent feature.
   • Depth is the distance from the frontage line to the opposite boundary of the site.
   • Frontage and depth influence visibility, access, and the configuration of building footprints.
   • Ideal frontage-to-depth ratios vary depending on the intended land use. For example, retail properties often benefit from wide frontage for maximum exposure, while industrial properties may require greater depth for storage and operations.
3. Corner Influence:
   • Corner lots, with frontage on two or more streets, can have both advantages and disadvantages.
     • Advantages: Increased visibility, greater access, and potential for multiple entrances. Often beneficial for commercial uses like gas stations, banks, and drug stores.
     • Disadvantages: Increased exposure to traffic noise, reduced privacy, higher maintenance costs for sidewalks, and potential setback restrictions. Corner lots may be less desirable for residential properties.
4. plottage❓❓ Potential:
   • Plottage refers to the increment of value that results when two or more adjacent sites are combined to create a larger, more valuable site.
   • Plottage value arises when the combined site has greater utility and supports a different, higher-value use.
   • For example, combining smaller lots in an industrial park to create a one-acre lot might significantly increase the value per square foot.
5. Practical Applications and Examples:
   • Retail Site Selection: Evaluate the shape and frontage of potential retail sites to ensure adequate visibility and access for customers.
   • Residential Subdivision Design: Design a residential subdivision layout that maximizes the usability of lots with varying shapes and minimizes the impact of irregular shapes.
   • Industrial Park Development: Determine the optimal lot sizes and configurations within an industrial park to accommodate different types of industrial users.
6. Related Experiments:
   • Shape Optimization Simulation: Use computer-aided design (CAD) software or Geographic Information Systems (GIS) to simulate different building layouts on irregularly shaped sites and assess their efficiency and development potential.
     • This could involve testing different building orientations, parking configurations, and landscaping designs.
   • Market Analysis of Corner Lots: Compare the sales prices of corner lots to interior lots in a specific residential neighborhood to determine if there is a premium or discount associated with corner locations.

3. Special Site Features

Special site features encompass a wide range of physical and environmental characteristics that can significantly impact site value and development potential. These features may be natural (e.g., Topography❓❓, soil conditions, water bodies) or man-made (e.g., utilities, easements, historical significance).

1. Topography:
   • Topography refers to the land’s contour, grading, and natural drainage patterns.
   • Slope: Steep slopes can impede building construction, increase development costs, and limit accessibility. Gentler slopes are generally more desirable.
     • Slope is often expressed as a percentage or ratio (e.g., 10% slope means a rise of 10 feet for every 100 feet of horizontal distance).
     • Slope (%) = (Vertical Rise / Horizontal Distance) * 100
   • Drainage: Adequate drainage is essential to prevent flooding and erosion. Sites located in natural drainage basins or downstream from other properties may have limited usefulness.
2. Geology and Soil Conditions:
   • The geological composition and soil properties of a site are crucial for building stability and suitability for specific uses.
   • Soil Bearing Capacity: The ability of the soil to support the weight of buildings and other structures. Low bearing capacity may necessitate special foundations, such as pilings or floating foundations, which increase development costs.
   • Soil Permeability: The rate at which water can infiltrate the soil. High permeability is desirable for septic systems and drainage. Low permeability can lead to waterlogging and instability.
   • Soil Composition: The proportions of sand, silt, and clay in the soil (see Soil Triangle for classification). Soil type influences drainage, fertility, and suitability for agriculture.
3. Floodplains and Wetlands:
   • Floodplains: Areas subject to periodic flooding, as defined by the Federal Emergency Management Agency (FEMA). Development in floodplains is often restricted and requires flood insurance.
   • Wetlands: Areas that are inundated or saturated by surface or groundwater, supporting vegetation adapted to wet conditions. Wetlands are protected by federal and state regulations, limiting development.
   • FEMA Flood Insurance Rate Maps (FIRMs) identify flood zones and provide data for flood insurance requirements.
4. Environmental Considerations:
   • Environmental Contamination: Presence of hazardous substances in the soil or groundwater, which can require costly remediation.
   • Threatened and Endangered Species: The presence of protected species on a site can restrict development activities.
   • Brownfields: Abandoned or underutilized industrial or commercial sites with potential environmental contamination. Redevelopment of brownfields is often encouraged through government incentives.
5. Utilities and Easements:
   • Availability of essential utilities (water, sewer, electricity, gas, telecommunications) significantly impacts site value and development potential.
   • Easements: Legal rights granted to others to use a portion of the site for specific purposes (e.g., utility lines, access roads). Easements can restrict development and affect property value.
6. Historical Significance:
   • Sites with historical or architectural significance may be subject to preservation regulations, which can limit development options.
7. Practical Applications and Examples:
   • Topographical Survey Analysis: Analyze a topographical survey map to identify areas of steep slopes, drainage patterns, and potential building sites.
   • Soil Testing: Conduct soil tests to determine bearing capacity, permeability, and the presence of contaminants.
   • Floodplain Assessment: Review FEMA flood maps to determine if a site is located within a floodplain and assess the associated risks and insurance requirements.
   • Environmental Impact Assessment (EIA): Conduct an EIA to identify potential environmental impacts of a proposed development and develop mitigation strategies.
8. Related Experiments:
   • Soil Permeability Test: Conduct a simple soil permeability test by measuring the time it takes for a known volume of water to infiltrate the soil. This can provide a qualitative assessment of drainage characteristics.
   • GIS Mapping of Special Features: Use GIS software to create maps showing the location of floodplains, wetlands, soil types, and other special features. This can help visualize the constraints and opportunities associated with a particular site.

Conclusion:

Site attributes, including size, shape, and special features, are critical determinants of value and development potential. A thorough understanding of these attributes, coupled with appropriate analytical techniques and scientific principles, is essential for effective site analysis and informed decision-making in real estate. Failing to properly account for these site attributes can lead to inaccurate valuations and flawed development plans.