Let's talk about the way properties are assessed.

Last year in Montgomery County, the 146,000 single-family properties were assessed at a total of $4 billion - which represents a fair market value of $8 billion. Some 126,000 of the properties included houses.

In addition, 13,000 condominium units were assessed at a total of $224 million. Condominiums and single-family residences comprise 74 per cent of the county's total assessable base.

All assessing in Montgomery County, except that of farmland, is related to market value, and foe condominiums and single-family dwellings the assessor has as especially broad basis for judging this value. In 1976, for example, nearly 10,000 single-family residental properties were sold in the county. The assessor uses such sales as a guide in estimating residential values throughout the county. (SECTION) ales are catalogued on a subdivision basis, and a sales analysis is developed for each subdivision. This analysis consists of a comparison of each sale with the previous assessment on the property, which determines the increase needed to bring the assessment up to 50 per cent of the market level.

Averaging out the increases in a subdivision provides the factor needed to bring assessments up to the 50 per cent level throughout the subdivision. As mentioned, because the base sales period is one to two-and-a-half years old, the assessment level in an inflationary period will average out at less than 50 per cent of market value at the date of finality (January 1 perceding the levy year).

Using this sales analysis to determine assessment changes and, therefore, total value for each property in a subdivision, the assessor next must estimate land values separately. These are shown on the worksheet for each individual property.

Essentially, the assessor determines the value of the improvement on the basis of the Appraisal Manual for Maryland Assessors, which is used throughout the State and is available in Montgomery County libraries. The manual establishes a cubic foot rate of the house. This rate determines the replacement cost of the structure (estimated value), allowing for depreciation based on age. This amount is subtracted from the total market value of the property. What is left is assigned to the land.

The land is usually broken down into rates per square foot, comprised of a prime rate for the minimum area required by the pertinent residential zone and lesser rates for amounts in excess of the minimum area. In a few places in the county, the assessor calculates land values on a front-foot basis rather than a square-foot basis. However, this method should not effect the total valuation.

For condominiums, assessments are based on unit sales in a condiminium development rather than in a subdivision.

This is done with the help of the appraisal manual or based on a percentage allocation between land and improvements.