Interior Elements and Space Functionality

Chapter X: Interior Elements and Space Functionality

Introduction:

This chapter focuses on the critical role of interior elements and their impact on the functionality and value of a building. Understanding how interior design, materials, and layout contribute to a space’s usability, aesthetics, and overall efficiency is crucial for accurate property appraisal. We will explore different components, scientific principles governing their behavior, and practical considerations for appraisers.

1.0 Interior Walls and Partitions

1.1 Load-Bearing vs. Non-Load-Bearing Walls:

• Load-Bearing Walls: These walls are integral to the structural integrity of the building. They support the weight of upper floors, roofs, and other structural elements. Removing or altering load-bearing walls requires careful engineering analysis and structural reinforcement to prevent collapse.
• Non-Load-Bearing Walls (Partitions): These walls primarily serve to divide interior spaces and do not contribute to the building’s structural support. Their removal or modification typically has minimal structural impact but can significantly alter the functionality of the space. Partitions are often made of various materials, including:
  • Wood studs with drywall (gypsum board)
  • Metal studs with drywall
  • Wire partitions
  • Glass
  • Wood panels
  • Plywood
  • Hardboard
  • Concrete
  • Solid masonry

1.2 Flexibility and Space Division:

Fewer load-bearing interior walls generally allow for greater flexibility in space division. This can be a significant advantage in adapting a building to changing needs or tenant requirements.

Practical Application: When appraising a building, identify and document the location of load-bearing walls. Note any modifications or alterations that have been made to interior walls and assess their impact on the building’s structural integrity and functionality.

2.0 Interior Supports

2.1 Components of Interior Supports:

• Beams: Horizontal structural members designed to resist bending moments and shear forces. They transfer loads from floors, roofs, or walls to columns or other supports.
• Columns: Vertical structural members designed to resist compressive forces. They transmit loads from beams, walls, or other structural elements to the foundation.
• Trusses: Structures comprised of interconnected members forming a rigid framework. Trusses are used to span long distances and support heavy loads, often in roofs and floors.
• Flooring Systems: These systems provide safe support for floor loads without excessive deflection and provide a base for the finished floor material. The flooring system includes:
  • Joists
  • Subflooring
  • Bridging

2.2 Materials and Characteristics:

Interior supports can be constructed from various materials, including:

• Wood: Common in residential construction, particularly for beams, columns, and trusses in older buildings.
• Steel: Used for beams and columns in commercial and industrial buildings due to its high strength-to-weight ratio.
• Concrete: Used for columns and beams, especially in reinforced concrete construction.
• Masonry: Used for columns and walls in some buildings.

2.3 Structural Analysis and Load Calculations:

The design of interior supports involves complex structural analysis to ensure they can safely carry the applied loads. Key concepts include:

• Stress (σ): Force per unit area within a material (σ = F/A), where F is the force and A is the area.
• Strain (ε): Deformation of a material under stress (ε = ΔL/L), where ΔL is the change in length and L is the original length.
• Young’s Modulus (E): A measure of a material’s stiffness, relating stress and strain (E = σ/ε).

Practical Application: When inspecting a building, look for signs of structural distress in interior supports, such as cracks, sagging, or deflection. Consult with a structural engineer if you suspect any structural problems.

3.0 Division of Space and Room Functionality

3.1 Number and Use of Rooms:

A building description includes the number of rooms in the structure and their uses. The number of bedrooms and bathrooms in a residential property usually influences the market and its value.

3.2 Room Size and Layout:

Room size and layout significantly impact a building’s functionality. Consider the following factors:

• Circulation: Efficient movement of people and goods within the space.
• Accessibility: Compliance with accessibility standards, such as the Americans with Disabilities Act (ADA).
• Usability: Suitability of the space for its intended purpose.

3.3 Basements:

Basements can be finished or unfinished. In some markets, the value is equal to the depreciated cost. However, there are places where the market does not recognize the value of basements as equal to their physically depreciated cost, and the values are diminished.

3.4 Condominiums:

The condominium declaration will identify the unit, the limited common elements, and the common elements. The condominium declaration will also identify the percentage of ownership in the common elements of the association.

Practical Application: Evaluate the room sizes, layout, and circulation patterns of a building. Assess whether the space is efficiently designed and meets the needs of its intended occupants. Compare the layout to similar properties in the market.

4.0 Storage Areas

4.1 Importance of Storage:

Adequate storage space is essential for both residential and commercial buildings. A lack of storage can negatively impact a building’s functionality and value.

4.2 Types of Storage:

• Cabinets: In kitchens and bathrooms for storing supplies and utensils.
• Closets: In bedrooms and hallways for clothing and personal items.
• Storage Rooms: Dedicated spaces for storing equipment, inventory, or other items.
• Mini-storage facilities: Frequently located near apartment complexes because apartment units often have inadequate storage space.

4.3 Trade-offs between Storage and Living Area:

It is important to remember about storage or closet space is that it takes away area from the rest of the structure.

Practical Application: Evaluate the quantity, size, and location of storage areas in a building. Assess whether the storage space is adequate for the building’s intended use and compare it to similar properties in the market.

5.0 Vertical Circulation: Stairs, Ramps, Elevators, Escalators, and Hoists

5.1 Design Considerations:

Designing vertical circulation systems involves careful consideration of safety, accessibility, and efficiency. Local building codes dictate the minimum and maximum tread and rise of stairs, which should be consistent within a building. The ADA established accessibility guidelines, and buildings accessed by the public that do not meet those regulations may suffer a value penalty based on the cost of necessary changes.

5.2 Types of Vertical Circulation:

• Stairs: Common in all types of buildings, providing access between floors.
• Ramps: Used to provide accessibility for people with disabilities.
• Elevators: Essential in multistory buildings for moving people and freight.
• Escalators: Used in commercial buildings to move large numbers of people between floors.
• Hoists: Used in industrial buildings for lifting heavy materials.

5.3 ADA Compliance:

The Americans with Disabilities Act (ADA) requires that public buildings be accessible to people with disabilities. This includes accessible stairs, ramps, and elevators. The ADA has specific requirements for:

• Ramp slope: Maximum slope of 1:12 (for every 12 inches of horizontal distance, the ramp can rise 1 inch).
• Stair tread depth and riser height: Minimum tread depth of 11 inches and maximum riser height of 7 inches.
• Elevator cab size: Minimum cab size to accommodate wheelchairs.

Practical Application: When inspecting a building, check for compliance with ADA requirements for stairs, ramps, and elevators. Assess the efficiency of the vertical circulation systems and their impact on the building’s functionality.

6.0 Interior Finishes

6.1 Walls and Partitions

• Types:
  • Walls and partitions can be painted, papered, or paneled.
  • Supplemental finishes include ceramic tile and wainscot paneling.
• Materials:
  • Wood studs covered with drywall materials (gypsum board, wood panels, ceramic tile, plywood, hardboard).
  • Plaster.
  • Masonry.
  • Structural insulated panels (SIPs).
  • Insulated concrete forms (ICFs).
  • Wire partitions
  • Glass
  • Wood
  • Plywood
  • Hardboard
  • Metals
  • Tile
  • Concrete
  • Solid masonry walls for fire protection

6.2 Flooring and Floor Coverings

• Types:
  • Sand, compressed dirt, bituminous paving, brick, stone gravel, concrete, and similar products.
  • Terrazzo flooring.
  • Wood in various forms.
  • Resilient, ceramic, stone, and quarry tiles.
  • Resilient flooring.
  • Carpeting.
• Characteristics:
  • Suitable for many industrial buildings, warehouses, garages, and basements.
  • Made of colored marble chips that are mixed into cement and ground smooth; used for high traffic areas such as the lobbies of public buildings.
  • Continues to be a popular material for floors.
  • Used in all types of buildings.
  • Usually a combination of vinyl and asphalt or laminate produced as sheet goods.
  • Once considered a luxury in residences, offices, stores, and commercial buildings, but today is widely used in all types of buildings.

6.3 Ceilings

• Types:
  • Ceilings can be drywall, plaster, or suspended panel (drop ceilings).
• Characteristics:
  • Ceilings that are too high or low for the property’s current highest and best use as improved may be considered items of functional obsolescence and decrease the property’s value.

7.0 Interior Painting, Decorating, and Finishing

7.1 Considerations for Interior Finishes and Decorating:

• If finished basements are used for purposes other than storage and these uses are accepted and typical in the area, they can add significantly to the property’s value.
• The types and finishes of various wall and ceiling components should be differentiated.
• A wide variety of flooring is available, and some flooring materials are selected primarily for their low cost and durability.
• Unique, restored molding can add value to older houses, but the use of moldings is decreasing.

7.2 Interior Painting and Aesthetics:

The attractiveness of painting and decorating is subjective. Many new owners and tenants will redecorate to suit their personal tastes. Unusual decorations and colors may have limited appeal and, therefore, may detract from a building’s value. The quality of decoration is sometimes an important consideration in valuing a restaurant, store, or other commercial building.

Practical Application: Evaluate the quality and condition of interior finishes. Assess whether the finishes are appropriate for the building’s intended use and compare them to similar properties in the market. Note any unusual decorations or colors that may detract from the property’s value.

8.0 Protection Against Decay and Insect Damage

8.1 Wood Decay

When wood is consistently exposed to moisture and water, destructive organisms propagate on or beneath its surface.

8.2 Insect Damage

Insects damage wood more rapidly and visibly than decay does. Termites are by far the most destructive to both damp and dry wood.

8.3 Protection Methods

• Sloping the ground away from foundations for good drainage.
• Putting vapor barriers on the interior sides of exposed walls.
• Using polyethylene as a soil cover in crawl spaces.
• Flashing, gutters, downspouts, and splash blocks to carry water away from foundation walls.
• Using poured concrete foundation walls, concrete caps over unit masonry foundations, wood treatments, soil treatments, or metal termite shields.

Practical Application: Look for signs of decay and insect damage in wood structures, such as rotting wood, insect holes, or termite mud tubes. Note any preventative measures that have been taken to protect against decay and insect damage.

9.0 Equipment and Mechanical Systems

9.1 Plumbing System:

Plumbing is an integral part of most buildings. It consists of supply, waste, and vent piping (which is usually covered or hidden except in industrial buildings) and fixtures and fittings (which are visible). Laundries, laundromats, and certain industrial buildings have elaborate plumbing systems.

• Piping: Consists of supply, waste, and vent piping. Materials include copper, cast iron, or plastic.
• Fixtures: Consists of bathroom fixtures (lavatories, bathtubs, showers, toilets, bidets, urinals) and kitchen fixtures (sinks, garbage disposals, dishwashers).
• Fittings: Consists of faucets, spigots, drains, shower heads, spray tubes, and floor drains in industrial buildings.

9.2 Heating, Ventilation, and Air-Conditioning (HVAC) System:

The HVAC system provides for human comfort.

9.3 Electrical System:

The electrical system provides power for lighting, appliances, and equipment.

Practical Application: Evaluate the condition and functionality of the plumbing, HVAC, and electrical systems. Note any deficiencies or code violations that may impact the property’s value.

Conclusion:

A thorough understanding of interior elements and space functionality is essential for accurate property appraisal. By considering the factors discussed in this chapter, appraisers can provide a comprehensive assessment of a building’s value and its suitability for its intended use.