Valuation Approaches: Cost, Sales Comparison, and Income

4. list the three basic activity zones of a house and describe their relationships to each other;
5. describe the characteristics that affect functional utility in the various rooms of a
   house,
6. identify the characteristics of various building components that can affect value❓, and
7. understand the technical terminology used to describe residential construction.
   I. Classification of Houses
   Houses are generally classified on the basis of four characteristics: the number of units, whether the building is attached or detached, the number of stories and the architectural style.
   The NUMBER OF UNITS refers to the number of separate households that the building is designed to accommodate. Although usage may vary in different areas, the term “house” is most often used to refer to a SINGLE-FAMILY RESIDENCE. If a building has multiple units that share a common access and other common areas, it is usually referred to as an APARTMENT BUILDING.
   A DETACHED HOUSE is one that is not connected to any other property. ATTACHED HOUSES share one or more walls, called “party walls,” that are jointly owned by the two adjoining properties. ROW HOUSES, common in many urban areas, are an example of attached dwellings. Ownership of an attached dwelling often involves a PARTY WALL AGREEMENT, which assigns responsibility for maintenance and repair of the party wall(s) (see Figure 7-1).
   A. TYPES OF HOUSES
   The “type of house” refers to the number of stories or levels in the house, and their relationship to each other.
   Although modern construction methods allow for all sorts of variations, the vast majority of houses fall into five basic “type” categories (see Figure 7-2):
8. one-story,
9. one and one-half story,
10. two-story,
11. split-level, and
12. bi-level (also known as split-entry or raised ranch).

Figure 7-1
Attached Houses
Multiples (Apartments)
Town House
Duplexes Row House
Illustrations courtesy of Marshall & Swift

Figure 7-2
Types of Houses
One Story
Bi-Level
One and One-Half Story
Two Story
Illustrations courtesy of Marshall & Swift
Split Level
1. One-Story House
A ONE-STORY HOUSE, often called a “ranch” or “rambler,” has its entire living area on the ground floor. It may or may not have a BASEMENT, which is a room of full story height located below the first floor, at least partially below ground level, and primarily not used for living accommodations.
The advantages of one-story houses include: ease of exterior maintenance, flexibility of floor plan design and the fact that there are no stairs to climb.
On the down side, this type of house is relatively expensive to build; by comparison, a two-story house with the same exterior dimensions has twice the living area, with essentially no extra cost for roof or foundation. (Roof costs for a one-story house are often minimized by using a low pitched roofline.)
One-story houses also require a greater amount of lot space in relation to the amount of living area, so they may be inappropriate or impractical on small or narrow lots.
2. One and One-Half Story House
Also known as a Cape Cod, the ONE AND ONE-HALF STORY HOUSE has a steeply pitched roof that permits part of the attic area to be used for living space. Roof dormers, which add to the amount of usable upstairs space, are a common feature of this type of house. As in the case of one-story houses, the foundation may or may not include a basement. Construction costs per square foot tend to be lower for one and one-half story houses than for one-story houses.
One and one-half story houses are often built with expandability in mind. Because the ground floor normally has at least one bedroom (and sometimes two), the upstairs level can be left unfinished until the extra space is needed. However, ease of expandability will depend on the quality of the original design and construction, which should allow for adequate access (stairs), ventilation (windows) and plumbing (bathrooms) on the attic level.
3. Two-Story House
Compared to a one-story or one and one-half story house, the two-story house is more economical in terms of construction cost per square foot of living space.
The reason for the economy is that square footage can be doubled without doubling foundation and roof system costs. This design also allows for the most living space on a given size of lot. Bedrooms are normally located on the upper floor, providing a natural separation between the public and private areas of the house.
A concern with all multi-level houses is the design and efficiency of heating and cooling systems. Because heat rises, a poorly designed system will make it difficult to keep the lower level warm in winter, and the upstairs cool in the summer.
With a well designed system, however, heating and cooling efficiency may actually be greater than for single-story houses, since the building has less exterior surface area relative to the amount of heated or cooled interior space.
4. Split-Level House
A SPLIT-LEVEL HOUSE has three or four different levels, which are staggered so that each level is separated from the next by half of a flight of stairs. Bedrooms and baths are located
on the top level. Half a flight down are the main entry, living room, dining room and kitchen. Down another half-story, beneath the bedroom level, is space for a family room, den or spare bedroom; the garage is often located on this level as well. A fourth level, equivalent to a basement, may be located below the living/dining/kitchen space.
The design of a split-level home lends itself to a sloped lot, where the garage and main entry can both open out at grade level. On a flat site, the main entry will be raised one- half story above the finished grade.
A split-level house has some of the same benefits as a two-story house in terms of construction, cost efficiency and natural separation of the various functional areas of the home.
5. Bi-Level House
A BI-LEVEL or SPLIT-ENTRY HOUSE has two main levels, one atop the other, with an entry or foyer located on a level halfway between. The lower level is sunk about halfway below ground, so the entry is even with the grade level. This design is sometimes called a “raised ranch,” since it is essentially a one-story home with a finished basement that has been raised partially out of the ground. The main rooms of the house are all on the upper level, with the lower story used for a family room or rec room, and perhaps a spare bedroom.
Since the lower level of a split-entry house is partly below ground, special care must be taken to provide adequate insulation and moisture proofing. Another drawback to this design is the lack of a basement or crawlspace in which to run pipes and ductwork.
Nevertheless, split-entry homes are cost-effective to build, and the finished lower level space is considered part of the “gross living area” for appraisal purposes in many parts of the country.
II. Architectural Styles
ARCHITECTURAL STYLE is the character of a building’s form and ornamentation.
If homebuyers in a particular area do not find a particular architectural style desirable, homes of that style are likely to sell for less than similar size homes having architectural styles which are more desirable within that community.
Architectural styles have traditionally been influenced by local factors such as climate and the availability of different building materials.
There are many examples of traditional architectural styles that are adapted to a particular location❓: Spanish style houses with thick adobe walls and tile roofs in the south❓west desert, Southern Colonial houses with deep shaded porches in the hot, humid South, or Cape Cod style homes designed for protection from cold northern winds in New England (see Figure 7-3).

Figure 7-3
Examples of Different Architectural Styles
Colonial Cape Cod (1) Cape Cod (2)
Cottage Victorian Mediterranean
Southern
Saltbox
Ranch
Chalet “A” Frame Contemporary
Illustrations courtesy of Marshall & Swift
Local traditional styles can still be found in many areas, but location is much less of an influence on architectural style than it used to be.
Builders are no longer limited to using local materials, since modern transportation systems make different building materials widely available at reasonable costs. The invention of central heating and cooling, as well as improved insulating materials, has broadened the range of architectural styles that can be adapted to local climates.
A. compatibility❓❓
COMPATIBILITY means that a building is in harmony with its use or uses and its environment. In terms of value, one type or style of house is not inherently better or worse than any other. What is most important to value is the compatibility of the design. Compatibility has several different aspects. To maximize value, the design of a house should be compatible with the designs of other homes in the area, with the physical and environmental characteristics of the building site, with the materials used in the construction, and with the preferences of the local market.
First of all, the design of a house should be compatible with the styles of other houses in the local neighborhood.
The market may welcome a limited degree of uniqueness in design, but value will generally suffer if the design contrasts too radically with surrounding houses.
Subdivision developers often impose design restrictions on their developments, because they know that compatibility of design will have a positive impact on property values in the subdivision.
Case/Example: A contemporary style house located in a neighborhood of other contemporary style houses is likely to be viewed positively by the market. But the same house located in a neighborhood of traditional style homes might seem “out-of-place,” and its value could suffer as a result.
Compatibility of design also refers to the suitability of the design for the particular building lot and location. Value is enhanced by a design that takes advantage of physical site characteristics, such as views. The design should also be appropriate for the topography of the site. For example, split-level designs often work well on hilly sites, while colonial style houses do not. Finally, the design should be appropriate for the local climate. A design that is specifically adapted to a hot desert climate, for example, would be inappropriate in an area with cool, rainy weather.
A building’s architectural style is often defined at least in part by the materials used in its construction. Spanish style homes have clay tile roofs, Tudor’s utilize timber framing, contemporary designs incorporate large areas of glass. A compatible design is one where the materials are appropriate to the style.
Case/Example: A clay tile roof on a Cape Cod house would look ridiculous to most potential homebuyers.
The final aspect of design compatibility is perhaps the most important: the design must be compatible with the demands of the market.
The popularity of any given design is influenced by the economic and social forces that affect value. As lifestyles and demographics change, so does the demand for different design features in housing.
Ultimately, it is the local market that determines what is a “good” design, and what is a
“bad” one.
Case/Example: A development of new contemporary style houses is built in an older community with mostly traditional style housing. If the market places an emphasis on the historic character of the community, the contemporary homes will be viewed as incompatible, and their value will suffer. On the other hand, if market forces are creating a demand for more modern housing in the community, the contemporary homes may not be incompatible at all, but may simply represent a new trend in community standards.
III. Elements of House Design
An appraiser must be able to identify the various elements of house design and evaluate any defects in those elements. The elements of house design include siting, interior functional zones, and room characteristics.
He or she may use mobile apps to reproduce accurate renderings to use for comparison purposes.
A. SITING
SITING refers to the placement of the house on the building lot. Placement is normally limited to some extent by building code set-back requirements, which call for minimum distances between the house and the property’s boundaries. Topographic considerations such as slopes or poor soil conditions may also limit where the house may be placed on the lot. Within these limits, however, careful placement of the house on the lot can have a significant impact on value.
There are four basic considerations in designing the placement of a house on its lot: orientation to the sun, orientation to prevailing storm winds, orientation to views, and the division of the lot into functional zones (see Figure 7-4).
Appraisers can create figures like the one above by using appropriate mobile apps.
Orientation to the sun affects the amount of light and heat that can enter the house. In most areas, a design where the living areas of the house face south is considered optimum. This orientation takes best advantage of natural lighting in the most used areas of the home, and helps maximize solar heat gain in the winter. Excessive summer heat gain can be avoided by using wide roof overhangs, which shade the house in summer when the sun is high in the sky, but allow light and heat to penetrate in the winter when the sun’s path is lower.
Screening with deciduous trees is another effective way to block the summer sun but still allow it to shine through in the winter when the trees are bare.

Figure 7-4
Exterior Functional Zone Example - Windbreak Layout
Cold Winter Wind
7 P.M. Sun
(low)
4 P.M. Sun
(high)
Morning
Sun
Cooling Summer Breeze
Noon Sun
(high)
In some areas, orientation to prevailing storm winds is an important siting consideration. In areas that are subject to frequent or heavy storms from a particular direction, it is best to minimize the amount of window area that is directly exposed to the winds, in order to cut down on heat loss. Entries should also be sheltered from the direct path of the storms.
An attractive view can add significantly to the value of a house. Views should be visible from the most used areas of the house. Even if the site does not have an attractive territorial view, careful landscaping can provide a pleasant view of the lot from the living area.
The last aspect of house siting is the division of the lot into functional areas or zones, the so-called public, private, and service zones. The area that can be viewed from the street frontage is the public zone. Areas shielded from the street by the house, or by fencing or other landscaping, constitute the private area. The service area includes access ways (driveway, walkways, etc.) and outdoor storage areas. Good design maximizes the amount of private area available for household activities.
B. INTERIOR FUNCTIONAL ZONE
An appraiser cannot underestimate the importance of FUNCTIONAL UTILITY, which concerns a building’s ability to perform the function for which it is intended according to current
market tastes and standards; as well as the efficiency of use in terms of architectural style, design and layout, traffic patterns, and the size and type of rooms.
A well-designed house should provide space for three basic activities: living, working, and sleeping.
Ideally, the spaces provided for each of these activities should be separated, so that one activity does not interfere with another. For example, bedrooms should be located where they will not be disturbed by activities in the living and working areas of the house.

Figure 7-5 shows how the spaces for the three different activities can be separated into zones. The LIVING ZONE includes the public areas of the house: the living room, dining room, family room and guest bath. The WORKING ZONE is comprised of the kitchen and laundry/ utility room. Bedrooms and private baths are located in the SLEEPING ZONE.

Figure 7-5 Interior Functional Zones
LIVING ZONE
Family
Room
Living
Room
Master
Bedroom
Fireplace
Ba.
Ba.
WORKING ZONE
Kitchen
Laundry Ba.
Dining
Area
Ent.
Bedroom Bedroom
SLEEPING ZONE
Garage
(Appraisers can create similar figures by using floorplan apps online.)
The separate activity areas of the home are connected by hallways, stairs and entry ways, which are sometimes referred to as a fourth zone of the house, the CIRCULATION ZONE. While the three activity zones should be designed to provide separation of the activities, they should also allow for easy circulation between and within zones.
Design features that affect desirability affect value because value is determined by supply and demand features of the marketplace.
A house’s value is affected by the building’s FLOOR PLAN, which is an architectural drawing indicating the exact layout of rooms and illustrating the functional or nonfunctional relationship between them. Structures with wasted space might lack space where it is otherwise desired so that the property will be less desirable to buyers than similar size homes.
How the designer allocates space affects desirability for many buyers. An example is while a custom 3,000 square foot home might have only two bedrooms because that is what the original owner wanted, to most potential buyers, the design would be a negative feature.
Case/Example: In a retirement oriented community, a two-story home without a bedroom on the first level is likely to be far less desirable than one with this feature.
C. ROOM CHARACTERISTICS
1. Kitchens
The kitchen is commonly the most used room of the house, so its design and location have a large impact on the functionality of the overall floor plan.
Kitchens should be conveniently accessible from both the main entrance and service entrance of the house, and should be located adjacent to the dining room and family room, if these rooms are included in the design. Also, the kitchen should be designed so that it is not necessary to walk through the working area in order to reach other rooms of the house.
A critical aspect of kitchen design is the work triangle, which is formed by the sink, refrigerator, and range. The distances between the three points of the work triangle can make the difference between an efficient kitchen design and a poor one. If the distances are too small, the kitchen will be cramped; if they are too great, preparing a meal will seem like a five-mile hike. A distance of four to seven feet between each point of the work triangle is considered optimal (see Figure 7-6).

Figure 7-6 Kitchen Work Triangle
SINK
REFRIGERATOR
STOVE
Kitchen sizes vary considerably. Eighty square feet❓ of space (8’ x 10’) is considered a minimum, but kitchens twice that size are not uncommon. Larger kitchens often include an eating area or family activity area. The design should include adequate counter and cabinet space, and plenty of electrical outlets for kitchen appliances.
Lighting and ventilation are important considerations in kitchen design. Overhead lights should illuminate all areas of the kitchen, and a vent or fan should be located over the cooking area to allow cooking fumes to escape. Natural lighting is desirable, but the placement of windows can be a problem. The best location for a kitchen window is over the sink. Additional windows are desirable so long as they do not take up space needed for wall cabinets.
Windows should never be placed over the cooking area.
2. Laundry/Utility Rooms
Laundry areas are best located where they are convenient to the sleeping area of the house, off the bedroom hallway for example. However, location of the laundry area is not as critical as most other rooms of the house, and laundries are often located in the garage or basement.
The laundry area should be well-ventilated, and located where noise from the appliances will not disturb others.
3. Living Rooms
The living room is the main public room of the house.
It should be located near the main (guest) entry, be separated from the sleeping area, and preferably be on the south side of the house. If the house has a dining room, it should be next to the living room. It should not be necessary to cross through the living room in order to reach the kitchen or bedrooms.
The size and shape of the living room should allow for easy arrangement of furniture. About 200 square feet is the minimum size, and rectangular shaped rooms tend to work best for furniture placement. The modern trend is for smaller living rooms, particularly in homes with a separate family/recreation room.
4. Family Rooms
In many areas, the FAMILY ROOM (also called a recreation room) has taken over the role of the living room as the main center of entertainment and socializing in the house. As part of the living zone, the family room should be separated from the sleeping zone; however, it is usually considered an advantage if the family room is next to (or near) the kitchen.
Since the family room is a center of activity for household members, direct access to the outside is also an asset.
5. Dining Rooms
Dining rooms may be formal or informal. A formal dining room or area is a separate room that is designed for that purpose. Informal dining areas are usually attached to or part of the kitchen itself, and may take the form of a nook or alcove.
The main considerations for the dining area are that it should be large enough to accommodate a dining table and chairs (including room to get in and out of the table), and it should have easy access to the kitchen so that food does not have to be carried through other areas of the house.
6. Bedrooms
The number of bedrooms has a major effect on house value.
Normally, homes with different numbers of bedrooms appeal to different segments of the market, that is, to families of different sizes or lifestyles. The average household size in the market will have a large impact on the desirability of three- or four-bedroom homes, as opposed to two-bedroom homes.
Ideally, bedrooms should all be located in a separate sleeping zone, to provide both privacy and noise insulation. The most common arrangement is to locate the bedrooms on a separate story or wing. Each bedroom should have convenient access to a bathroom, either directly or via a private hallway. Also, it should not be necessary to go through a bedroom to reach another room (other than a private bath).
Depending on the room layout, a size of 9’ x 10’ is the minimum needed to allow for a single bed, 10’ x 12’ for a double bed. Whether larger room sizes will add to value depends on local market preferences. Most homes have at least one bedroom that is larger than the others, the MASTER BEDROOM. Modern master bedrooms will often have walk-in closets and other amenities.
Each bedroom should have its own closet, and the closet should be large enough to be functional.
7. Bathrooms
The number of bathrooms in a house has a significant impact on its value.
For example, a four-bedroom house with only one bathroom is likely to be viewed as functionally obsolete. The desirability of more than two bathrooms will depend on the size of the house, and on the local market.
At a minimum, all houses should have a full bathroom with a toilet, sink and shower or tub. Better homes will have at least one half-bath (toilet and sink only) in the living area, in addition to the main bathroom(s).
Bathrooms should be centrally located in relation to the bedrooms, and should also be easily accessible from the living areas of the house. For bedrooms, a bathroom or half-bath is preferable over one that is farther away. Master bedrooms should ideally have their own private baths.
The size of a bathroom should be adequate to allow for easy use of the plumbing fixtures, and the floor plan should provide a degree of privacy.
Bathrooms should always be well ventilated, whether by a window or a ventilation fan.

IV. Construction Methods and Materials
In addition to understanding the fundamentals of house design, a competent appraiser must have a working knowledge of basic construction methods and materials. While expert knowledge of construction engineering is not needed for most appraisal assignments, familiarity with typical materials and construction practices is essential for appraising value. The following section will discuss building methods and materials, in the order in which they are commonly used during construction, beginning with the foundation and working up to the interior finishes.
A. Foundations
The FOUNDATION is the base or understructure of a building, and the component of the building that transfers its weight and loads to the ground. A good foundation transfers the weight of the building evenly, prevents settling, and seals out moisture and pests.
All foundation types must extend below the frost line to prevent movement due to freezing and thawing of the ground.
The foundation consists of two basic parts, FOOTING and FOUNDATION WALLS. The FOOTING is the underground base that supports the foundation walls. Footings spread out the weight of the building over the ground, preventing excessive settling.
Most foundation walls are constructed directly on top of the footings. The foundation walls extend upward from the footings and form the perimeter of the basement or crawl space.
1. Types of Foundations
There are four main types of foundations: slab, basement, crawl space, and pier and beam (see Figure 7-7).

Figure 7-7
Types of Foundations
Basement Crawl Space Pier and Beam
Slab on Grade
1) The SLAB-ON-GRADE foundation (also known as a floating foundation or monolithic slab) is the simplest and least expensive type of foundation. Slab foundations are used where ground conditions permit, typically in areas where the ground does not freeze.
A slab foundation consists of a slab of concrete that is poured directly on the ground, resting on a bed of gravel.
2) A BASEMENT FOUNDATION has a full-story or partial-story living area below grade. Basement foundations are common in areas where the ground freezes during the winter, because they must extend below the frost line, which is usually 4 to 6 feet below the surface. The main advantage of a basement is that it provides additional living space, usually at a lower cost per square foot than space above grade. The basement may also serve to elevate the living area above flood prone areas.
3) CRAWL SPACE foundations are similar to basement foundations, except that they are not full-story height. The crawl space foundation provides an area to access piping or ductwork below the first floor. Crawl space foundations also tend to elevate the living area of the house above flood prone or termite infested areas.
4) A PIER AND BEAM foundation is used when the soil cannot adequately support a slab or basement type of foundation. The foundation is constructed by sinking piers into the ground and then spanning beams between the piers, which then support the floor joists. Pier and beam foundations can be very expensive, particularly if the piers must be sunk to a considerable depth in order to reach stable soil.
2. Foundation Materials
All foundation types use durable materials, such as concrete, stone or treated wood. Most modern foundations are constructed of reinforced concrete. Stone is often used in pier and beam type foundations.
The type of foundation required depends on climate, soil conditions, local construction costs and other factors.
B. Framing and Sheathing
The next major step in constructing a house, after building the foundation, is erecting the frame. Framing is the basic load-bearing skeleton of the house, to which interior and exterior walls are attached. The frame gives the house its basic shape and strength.
All framing must be designed to safely withstand the forces of gravity (dead and live loads), wind, and earthquakes. Building codes regulate the size and type of lumber and the spacing of structural members in order to ensure that the frame is of sufficient strength to withstand local weather conditions.
1. Framing Lumber
Wood is the most common framing material. (Other materials, such as steel or concrete, are occasionally used, but for the most part framing is synonymous with wood framing).
Wood for structural framing should be dried before it is used in construction, to prevent warping and twisting.
FRAMING LUMBER is graded for strength, appearance, and freedom from defects. For uses where strength is critical, such as foundation walls, the lumber is graded according to the maximum load that it will safely bear. Load-bearing lumber is commonly graded into the following classifications:
a. Select Structural Grade b. No. 1 Grade
c. No. 2 Grade d. No. 3 Grade
Wood products used for framing are available in a variety of forms (see Figure 7-8).

Figure 7-8
Types of Lumber
Solid Sawn Lumber Laminated Veneer Lumber (LVL)
Wood I-Joists Parallel Strand Lumber (PSL)
Glue Laminated Beams (Glulam)
SOLID SAWN LUMBER is produced by sawing the log directly into boards.
Solid sawn lumber used to be the standard for building material.
LAMINATED VENEER LUMBER (LVL) is an engineered lumber product made by bonding layers of thin wood together with adhesives.
This product is used for headers, beams, rim boards, and edge-forming material for concrete pours.
WOOD I-JOISTS are another engineered lumber product. Wood I-joists use less old-growth timber. They are easily produced, lighter, straighter and stronger than solid lumber. They are used for floor joists and roof rafters.

PARALLEL STRAND LUMBER (PSL) is an engineered lumber product used for beams and columns.
GLUE LAMINATED BEAMS (Glulam) are another engineered lumber product used to support a load over long spans.
Green Technology: Renewable resources from natural sustainable tree farms are being utilized for the production of lumber products as well as bamboo flooring.
2. Framing Terminology
Before discussing framing methods, we need to introduce some of the terms that are used to describe the structural members of a frame. Figure 7-9 shows the main components of a typical wood frame.

Figure 7-9
Wood Framing Terminology
Sill
Studs
Top Plate
Rafter
Joists
Header
a. SILL is the wooden member that rests directly on the foundation.
b. STUDS are the vertical framing members of a wall.
c. TOP PLATE is the horizontal framing member that sits on top of the studs in a wall. d. JOISTS are horizontal framing members that support a floor or ceiling.
e. RAFTER is a framing member that supports a roof.
f. HEADER is a beam over a window or door opening.

3. Framing Methods
   There are three primary framing methods: balloon framing, platform framing, and post and beam framing. Platform framing is the most common type of framing used in modern residential construction.
   a. Balloon Framing
   With balloon framing, the wall studs run continuously from the foundation sill to the roof. The advantage of balloon framing is that it creates a very strong wall; however, balloon framing is difficult to erect and creates a fire hazard, since there is an open channel inside the wall from the foundation to the roof. For this reason, balloon framing is rarely used in modern construction.
   b. Platform Framing
   With platform framing, a wood frame platform is constructed on top of the foundation wall, and then the wall framing is erected on the platform. The second story is constructed on top of the first story walls, and the roof framing is erected on top of the second story walls.

Each story of the house is framed as a separate unit.
Platform framing is easier to erect than balloon framing, and it provides an effective fire stop at each floor level. Platform framing is sometimes used in conjunction with truss roof systems.
c. Post and Beam Framing
Post and beam framing can be used to create an open interior space, with few interior walls. Post and beam framing utilizes heavy timbers spaced several feet apart for vertical support (posts) and horizontal support (beams). Exterior walls can be made of any material, and interior partitions are not required to be load bearing.
4. Roof Framing
The term “roof framing” refers to all of the framing members that support the roof. These members may include: Rafters, Trusses, Joists and Sheathing. The type of roof framing needed depends on the type of roof, which is influenced by the roof’s pitch and shape. PITCH is the degree of slope of the roof (vertical rise in inches, per horizontal foot). SHAPE is the configuration of the roof (gable, hip, flat, etc.)
a. Roof Shapes and Terminology
Common roof shapes include: gable, hip, flat and shed (see Figure 7-10).

Figure 7-10
Roof Shapes
Gable Hip Flat
Shed
Rafters are used to support roofs with moderate pitches, typically over a span of 24 feet or less. Rafters are commonly spaced two feet apart, and support the roof’s sheathing.
Truss Roof Systems
Truss roof systems, on the other hand, are self-supporting, and allow for spans of 40 feet or more. Trusses can be designed for almost any roof shape. They are assembled at the factory from standard dimension lumber, and trucked to the building site for installation. Truss roof systems are frequently used in conjunction with platform framing, since interior bearing walls are not required with a truss roof system.

b. Chimneys, Stacks, and Vents
These are vertical conduits to allow fumes and smoke from heating apparatus, stoves, and fireplaces to safely exit the structure. Modern structures typically have vents and stacks instead of chimneys that service natural gas and electric heating appliances.
4. Sheathing
SHEATHING consists of sheets or panels that are nailed to the outside of the framing members (studs or rafters), to strengthen the structure and provide a base for exterior siding.

C. Exterior Finishes
In general, EXTERIOR FINISHES protect the building from the weather. They also play a significant role in determining the overall architectural style of the house. The choice of siding material affects both the appearance and maintenance requirements for the building’s exterior. Common exterior finishes include: wood, brick, stone, stucco and vinyl. Wood, brick and stone siding can last for many years but require a high level of maintenance.
Stucco is a mixture of cement and plaster, that is applied over a metal mesh base.
Stucco is durable and resistant to fire, but can crack if it is not properly applied.
Vinyl siding is economical and requires minimal maintenance, but may not be architecturally compatible with all styles of homes or all neighborhoods.
D. Doors and Windows
Doors and windows are critical components of exterior finishes because of the important role that they play in design compatibility, access, and energy efficiency.
1. Doors
Exterior doors come in several basic types. Wood or metal doors offer security and privacy. Glass doors provide natural lighting and views. Doors of all types may be solid or hollow. All exterior doors should be weather-stripped to prevent air infiltration.
Most modern entry doors are pre-hung for ease of installation. The door is already hinged to the frame, and the frame is made to fit a standard-sized opening (ROUGH OPENING). The door FRAME (also called the JAMB) should fit snugly in the opening, and the door should swing freely and close tightly.

2. Windows
   Like doors, windows serve to provide access and natural lighting, and they also play a significant role in the architectural design of the building. A primary function of the window is to admit light and provide a view of the outside world. However, windows also constitute a significant point of heat loss during the winter, and of heat gain during the summer.
   When choosing windows, the appraiser should consider cost, performance, appearance and installation ease. For exterior walls, the common types of windows are listed in Figure 7-11.

Figure 7-11
Common Types of Windows
Double Hung
Casement
Slider
Awning

Double hung windows are the traditional type of window, with two sashes that can slide up and down. Casement windows are hinged at the side and swing outward. Sliding windows have two sashes that slide horizontally. Awning windows are hinged at the top and swing outward.
Older windows are single pane, which allow high rates of heat loss.
Windows can be purchased with single-panel, double-panel or triple-panel glazing. DOUBLE-PANE windows (also known as double-glazed windows or insulated windows) have two panes of glass with an airspace in between. The airspace may be sealed with inert gas, for even greater insulation. MULTIPLE-PANE windows can greatly reduce heat loss.
Window FRAMES are commonly constructed of wood, metal, or vinyl. Wood frames provide good insulation, but require regular maintenance to prevent rot. Metal frames are durable, but conduct heat more readily than wood or vinyl. Vinyl frames are durable and require little maintenance. Windows should also be weather-stripped.
Increasingly “Green building” is becoming a part of mainstream design and construction and can affect value positively. The term “green building” can involve materials, design, energy efficiency and water conservation among other things.
Low Emittance Glass
This window material refers to a very thin transparent film applied directly to the window’s surface that reflects heat while letting light in.
High R Values
Windows are rated by their resistance to temperature transfer by a number called an R VALUE. This number determines heat loss and gain. Windows with a High “R” number have better insulative characteristics.
The level of fenestration (the design and placement of windows) also affects energy usage in building.
Bamboo Flooring
Bamboo is a fast growing wood product that requires little time from planting to harvest. Bamboo can be harvested in only five to seven years and then can quickly be re-planted.
E. Insulation
INSULATION retards heat transfer into and out of the building, and thereby reduces fuel costs for heating and cooling. It has been proven that increased insulation can increase property value.

Insulation is normally rated according to its R-VALUE. The R-VALUE is a measure of thermal resistance, that is, its ability to prevent heat flow. The higher the R-value, the greater the degree of insulation.
The required amount of insulation varies according to climate. Insulation is most important for ceilings, exterior walls, and floors.

Common types of insulation include: fiberglass batts, mineral wool batts, cellulose fiber (blown in), and foam.

F. Ventilation
VENTILATION provides for air circulation throughout the house.
Ventilation removes stale air and excess moisture, preventing condensation that can damage the structure and promote growth of molds and fungus. Ventilation is also necessary to remove gases from combustion-type heating appliances. Adequate ventilation is provided by operable windows and doors, but it is also a good idea to have vents for air intake and exhaust, particularly in the attic, bathrooms and kitchen.
G. Interior Finishes
Interior finishes have a large effect on value, both because of their appearance, and because they influence the quality of interior lighting, sound, and air quality.
1. Wall Finishes
The vast majority of modern interior walls are constructed from drywall. A panel of SHEETROCK also referred to as gypsum board, which is manufactured in standard widths and lengths, is nailed or screwed to the wall studs.