What is a Histogram? Why is it Important in Real Estate Data Analysis for Portland, Oregon?

Appraisers endeavor to take the measure of a neighborhood with a variety of charts and graphs. It helps them to frame the value opinion and see how the subject property relates to the neighborhood or market area as a whole. 

A histogram is a graphical display of data using bars of varying heights. In a histogram, each bar groups data for a single variable into ranges (or bins). Taller bars show that more data falls in that range. A histogram may be used to display the shape and spread of the data of the real estate market and illustrate trends of properties that have sold and/or are listed. They’re a great visual tool!

Example

Lot Size

The above histogram depicts the various lot sizes for detached single-family residences in the Ladd’s Addition historic district. The data represents sales and/or listings in the RMLS database from the year 2000 to July 2019. What can we learn from the above chart?

1) There is a tight uniformity of lot sizes in this district. 57% of the data falls into just one bin! 
2) 87% of the data falls into the bins representing lots from 0.08 acres to 0.159 acres (~3,485 sq. ft. – ~6,926 sq. ft.). This shows that large lots in Ladd’s addition are rare.
3) Properties outside the aforementioned bins would require more careful analysis by the appraiser (or agent).
4) Dealing with extreme outliers (properties on tiny lots or larger ones for the district) may require the use of a number of data science and appraisal techniques as comparable properties would be hard to find.
5) There is little developer potential for subdividing lots as virtually no lot is large enough to be reasonably partitioned.

Portland Real Estate Market

As you can see, you can squeeze a lot of information out of just one histogram. These charts can be used to display many different variables: age, gross living area, bedroom & bathroom count, sales prices, etc. By evaluating histograms of several key metrics, one can quickly see how a particular property fits into a neighborhood (or district) as a whole.

The Portland market is eclectic and appraising unusual properties requires the careful application of local expertise, the tools of statistics and data science, and sound judgement.  

Appraisal Reports

If you are a homeowner and are looking to sell your home, you would greatly benefit from a prelisting appraisal. Our firm will bring high-level analytics to your report and give you a sound understanding of the current market.

If you are an agent and need detailed neighborhood analysis, or analysis of specific areas or specific segments of the market, please contact us and we can generate a custom report to help you frame a listing price for your client!

Ladd’s Addition—Neighborhood Analysis of Single-Family Residential Homes (July 2019)

Ladd’s Addition is a unique historic district in the city of Portland that is known for its diagonal street pattern radiating from a central park spoke—the Ladd Circle Park & Rose Gardens. Ladd’s addition is named after the 19th century Portland mayor, William S. Ladd. This historic district is part of the Hosford-Abernethy neighborhood. The street layout is easy to spot from aerial maps of the city and clearly delineates the district’s boundaries.

2018-11-07_18-10-38

Appraisers endeavor to take the measure of a neighborhood with a variety of charts and graphs. It helps them to frame the value opinion and see how the subject property relates to the neighborhood as a whole. For this blog post we will use the venerable histogram to better understand the single-family residential market for Ladd’s Addition.

A histogram is a graphical display of data using bars of different heights. In a histogram, each bar groups numbers into ranges. Taller bars show that more data falls in that range. A histogram may be used to display the shape and spread of the data of the real estate market and illustrate trends of properties that have sold and/or are listed. They’re a great visual tool!

The following information is based on detached single-family residential homes that were sold and/or listed on the open market as reported by RMLS—the primary MLS service for the City of Portland. Data was pulled from the year 2000 to the present date.

Age

Age

Most properties within Ladd’s Addition were built around 1900-1930. This is reflected in the age histogram showing most of the homes falling in the 91-97 years bracket. New/newer constructions in Ladd’s addition is nearly unheard of.

35 different homes that sold over the last 20 years were on the National Register of Historic Places.

Bathroom Count

Bathroom

Most homes in the neighborhood have two bathrooms; but a home with only one bathroom is not uncommon. One home had the equivalent of 5 & 1/2 bathrooms. There is no waiting in that house!

Bedroom Count

Bedroom

Two to four bedrooms is the norm, with a few outliers having either one or 6-7 bedrooms.

Garage Stall Count

GAR

A one-car garage is the norm for Ladd’s Addition. However, a substantial number of homes in the dataset have either no garage at all or an extra garage stall.

Total Square Footage

Total SF

This metric includes above-grade living area and basement space for a combined figure. The median total square footage for the neighborhood is 2,500 sq. ft. There are some larger homes in the area, with 32 sales/listings being at or above 4,800 sq. ft.

Gross Living Area

GLA

Gross living area only consider non-basement living space. Often the market reacts more strongly to gross living area, usually applying a discount to basement space. Median gross living area is approximately 1,700 sq. ft.

Level Count

# of Levels

The majority of properties are three levels in this neighborhood.

Lot Size

Lot Size

The vast majority of properties are on lots 0.120 ac – 0.129 acres (~5,227 sq. ft. – ~5,619 sq. ft.). There is substantial uniformity of lot sizes in this neighborhood.

Sales Price

Sales Price

This histogram includes sales prices over a 20-year period. The highest sales price obtained in the neighborhood (on the open market) was $1,105,000 on 3/17/2017.

# of Sales

# of Sales

Ladd’s Addition doesn’t have a substantial turnover of homes each year. The fewest sales in a year was back in 2015, when only 10 single-family residential homes sold. 2016-2018 averaged 20 sales per year. This year looks to be trending lower. Year-to-date sales are only 8 and, if the trend holds, 2019 may signal a cooling off of the number of sales.

So, there you have it, a brief histogram overview of one of Portland’s most iconic neighborhoods!

Appraisal Reports

If you are a homeowner and are looking to sell your home, you would greatly benefit from a prelisting appraisal. Our firm will bring high-level analytics to your report and give you a sound understanding of the current market.

If you are an agent and need detailed neighborhood analysis, or analysis of specific areas or specific segments of the market, please contact us and we can generate a custom report to help you frame a listing price for your client!