What is mass appraisal?


Assessors must value all real and personal property in the community to their full and fair 

cash value.  Mass appraisal is the process used by every Massachusetts City and town to 

create the property assessments. Assessments are based on an analysis of Windsor’s entire 

real estate market for a specified period of time.  This study guides the setting of valuation 

parameters that are used to calculate the property values town-wide.  It differs from the more 

well-known “bank” or fee appraisal.  Although the appraisal concepts are the same and the 

results similar, the process is different. No particular sale or group of sales is used to 

determine the value of your property, but all of a certain calendar year’s sales are included in 

the analysis that set the parameters for the next fiscal year.


What is market value?


Market value, or full and fair cash value, is the most probable price for which a property will 

sell in an open, competitive market that a willing buyer will pay for a property to a willing 

seller, both acting knowledgeably and prudently and neither being under any obligation to 

buy or sell.  Sales such as foreclosures and family sales are not considered to be “arms-length” 

or fair market transactions.


When my neighbor's house sells, will their price determine my assessment?


Not necessarily.  As explained in the previous question, sales are analyzed town-wide.  An

example of what could be relevant is if there were several sales in an area indicating that the 

assessments were too low compared to the sales prices.


How often does the valuation of properties change?


Every year the Assessors subject the arms-length sales that occurred in the prior calendar 

year to a statistical examination based on market area, style of house, age of house, effective 

area, size of lot and sale price to see what changes the market has shown.  The tables used in 

the Computer-Assisted Mass Appraisal (CAMA) system are adjusted so that the median 

assessment of the sales sample is within 10% of 100% of market value, and the dispersion of 

the assessments to sales ratios in the sample are within state guidelines.  These new factors 

are then applied to all properties for the new Fiscal Year.  Every third year the Department of 

Revenue (DOR) requires each city or town to conduct a revaluation.  This is a year-long 

process during which the DOR examines every phase of the assessing operation before 

certifying the values.  During the two years in between revaluations the Assessors may change 

the values if sales activity so indicates.  These yearly updates are called Interim Year 

Adjustments. The last Re-certification was completed in fiscal year 2016.


How is the calendar year different from the fiscal year?


Massachusetts cities and towns operate on a “Fiscal Year” basis.  The calendar year runs from 

January 1st through December 31st.  The fiscal year goes from July 1st through June 30th.  

The assessment date is January 1st preceding the fiscal year.  That is, for Fiscal Year 2016 the 

assessment date is January 1, 2015.

Where can I find the detail on my property?


Property record cards, which contain ownership information, visit history, land and building 

details, and other notes, and which display a property’s valuation, are available in the 

Assessors’ office, 1890 Route 9.   You can also view your record card and many of these details 

on-line using the link available on this web site.


What do the assessors look at when determining an assessment?


The assessor collects many data elements about a property in order to develop the total 

valuation.  The most significant factors in determining the value are location and land area 

and style, quality, size, condition and age of the building(s).  Other factors include amenities or 

detriments as well as features in the building such as number of bathrooms, type of 

heating/cooling, interior/exterior finishes, and special features including fireplaces, saunas 

and Jacuzzis.  Also considered are detached structures.


How do I know if my valuation is fair and equitable?


The best comparisons are to properties that have sold that are the most similar in the most

aspects to your property.  You can also compare your property’s assessment to the 

assessments of the most similar properties.  Although properties will most likely never be a 

perfect match, assessments for similar properties should fall in a close range of valuations.


How can my assessed value increase (decrease) when I did not do anything to the property in 5 years and I am not selling the property?


The assessed value represents the estimate of market value of the property.  The real estate 

market changes constantly. The assessment for FY2016 represents the estimate of market 

value as of January 1, 2015.  This estimate of market value is determined by examining sales 

of properties from calendar year 2013 and 2014 (we use two years due to lack of sales data in 

Windsor).  Although there may not have been any physical changes to the property, buyers 

may be paying more or less for properties than they were in previous years.  The assessment 

changes reflect the changes in the purchase prices of similar homes in the neighborhood. The 

assessments do not predict market value.  The assessments reflect (or report) market value.  

The real estate market can change dramatically from year to year.  Buyers and sellers 

determine the market value of properties.  The assessments reflect what the buyers and 

sellers are doing as of the assessment date.


What will happen if I put an addition on my property? Are the actual construction costs of a new home used to determine the new assessment?


Historical sales have indicated that larger properties sell for more than smaller properties 

with all other factors being equal.  If an addition is put on a home, the house becomes larger. 

The assessors would then have to see what similarly sized properties were selling for in the 

neighborhood.  It is highly likely that the assessed value of your property will increase once 

the addition is put on the property.  Generally speaking, improvements that increase the 

market value of a property will increase the assessment.


Why did my valuation change from the prior year's valuation more (less) than my neighbor's?


Market value changes occur in many forms.  From year to year economic conditions and local 

factors change and influence the values of different classes of property in different ways.  

Buyers have different requirements and these requirements sometimes change from year to 

year.  Renovations may have been performed on a property that would cause a change in 

assessed value different from a similar property that did not undergo renovations.  A recent 

inspection by the Assessor’s office also may have contributed to a change in assessed value, 

perhaps adding something that had been missed or reducing something that was overstated.  

Your style or size or land area or other factor(s) may differ from your neighbor’s and that 

caused the valuation changes to differ.


I think my assessment is out of line with my neighbor's property, whose property is assessed lower. I want my assessment to be as low as theirs.


The first step in comparing properties is to examine the factual components of each property.  

Many times properties that appear larger are in fact much smaller than people think.  Quality 

characteristics should also be examined when making comparisons.  Ultimately, the assessors 

have to determine if the assessment represents market value on the subject property and also 

if the assessed value on the neighbor’s property represents market value.  If a neighboring 

property is too low in relation to surrounding properties, the assessors cannot compound 

their low assessment by also lowering surrounding properties. The resolution may be that 

the assessors have to raise the neighboring property’s assessed value to make it more in line 

with the surrounding properties. The most important criterion the assessors examine in an 

abatement request is the market value of the property of the person filing the abatement and 

the market value of any property that the person filing the abatement mentions on the 



I recently purchased my home for a price which is different than the valuation for this year. How is this possible?


The real estate market is not a “perfect market” and price is not always equal to value.  Similar

properties usually do not sell for exactly the same price because the motivations of buyers 

and sellers are not always similar.  Similar properties usually tend to sell within a “value 

range” rather than for one specific price.   According to the definition of fair market value, 

your value represents “the most probable selling price” and tends to be the middle of the 

range of what similar properties have recently sold for. Therefore, your appraised value 

could be higher or lower than what you actually paid for your property.


In addition, state laws (statutes) require that real estate be assessed at 100% of market value 

as of January 1st immediately preceding the current fiscal year. This is the assessment date.  

The sales considered in order to determine the market value are those that took place during 

the calendar year prior to the assessment date.  If your sale took place subsequent to the 

assessment date, it will be in the group of sales analyzed in the preparation of the following 

year’s valuations, and is not relevant to the current year’s valuation.


Why does the Assessor need to enter my house?


A total inspection of all factors that influence the value results in the most accurate 

assessment of a property.  We request the inspection in order to be as fair and accurate as 

possible.  Items such as condition of the rooms, quality of the finish, areas of finished versus 

unfinished, can only be confirmed with an interior inspection.  Without actual information, 

estimates of the interior information have to be made.


Will an inspection change the value of my house?​


Depending on the accuracy of the current data about the property, it may or may not.  

However, the valuation for the current fiscal year will not be changed mid-year unless your 

property meets the strict qualifications for a supplemental tax bill (usually only major new 

construction), which Windsor does not currently have the authority to do.


What happens if I refuse to allow the property lister to enter my home?​


You do not have to allow the assessors into your home.  However, if an assessor is denied 

entrance, property owners give up their ability to challenge the assessed value.


Will I be penalized if I allow the assessors in and my neighbor does not?​


In instances where the assessors do not get into a property, estimates are made about the 

condition of the interior of the property.  Accurate assessments are based on accurate 

information.  By allowing the assessors to view the interior and exterior of your property, 

your assessed value is based on accurate information.  If a person does not allow the 

assessors to view the interior and exterior of a property, estimates are made about the 

condition of the interior of the property, the kitchen and bath qualities, and where there is 

finished attic space and finished basement space.  If the estimates are overstated, property 

owners may contact the assessor’s office to arrange an interior and exterior inspection of 

their property.

How is the tax rate calculated?


The tax rate, in its simplest form, is the tax levy divided by the town’s taxable valuation.  This 

is called the Uniform Tax Rate.  At the May Annual Town Meeting residents vote 

appropriations for the upcoming Fiscal Year.  This is called the tax levy.  The Assessors’ 

primary responsibility is to find the “full and fair cash value” of your property so that the 

taxpayer may pay only his/her fair share of taxes.


How will the new valuation affect my tax bill? If my assessment went down, how can my tax bill go up?


Individual assessments may rise or fall depending on the characteristics of the property.  The 

purpose of mass appraisal is to value all property by the same standards at the same time to 

create an equitable distribution of the tax levy.  If the same amount of money is to be raised 

for the current year after a valuation update from the previous year, and each assessment has 

doubled, the tax rate would be cut in half; and vice versa, if each assessment decreased by 

20%, and the same amount of money was to be raised, the tax rate may increase by 20%.  

Increases or decreases in assessed values to not cause a tax increase or decrease.


How can my tax bill go up more than 2.5%? Doesn’t Proposition 2 ½ limit the tax increase?


Proposition 2 ½ limits the amount of taxes Massachusetts communities can raise for the 

current year from the previous year’s levy limit. To this a town may add new growth 

(increased valuations caused by new construction, renovations or land use changes) and 

overrides voted by the town.


I cannot afford this tax bill (on fixed income, lost my job, have financial issues). Can’t the Assessors lower this assessment to accommodate this situation?


By law, the Assessors must value all property at 100% of full and fair cash value, using methodologies approved by the DOR applied consistently to every property. Properties need to be valued without regard to the owner’s ability to pay the taxes. (See exemption section below for some programs that are available for some tax relief.)

What's the difference between an abatement and an exemption?


An exemption is a discharge from the obligation to pay all or part of a real estate tax based on 

certain age, income, military, or disability status as set forth by the Commonwealth of 

Massachusetts.  An abatement happens as a result of an adjustment that lowers a property’s 

valuation after the actual (not preliminary) tax bill has been issued.  Exemptions are available 

for seniors, low income seniors, surviving spouse or surviving minor child, veterans with 

disabilities, and blind persons.


Are there other ways to reduce my taxes?


There is also a tax deferral program available for older citizens.  Please contact the Assessors’ 

office for further information.


Does the property record card reflect any exemptions to which I may be entitled?​


Property tax exemptions are available to qualifying taxpayers according the eligibility 

requirements determined by state law.  Exemption information is not displayed on the 

property record card.  Information on exemptions is available on the town’s web site or in the 

Assessors’ office.


What if I feel the value of my property value is overstated?​


This is when an owner would file for an abatement.  There are three basic reasons for 

granting an abatement: data error(s), overvaluation, or inequitable assessment.   An 

abatement application is not a complaint about taxes or how much your assessment has 

increased.  It is an attempt to prove that your property’s estimated market value is inaccurate 

or unfair based on recent sales of comparable properties.


Do I have to apply for an abatement every year if I received one in the past?


Not necessarily.  If a data correction or adjustment has been made that should be permanent, 

it will carry forward to the next and following years until such time as there is a change in the 

property and/or a change in the valuation methodology that affects that property.  Therefore, 

it would not be necessary to reapply the following year(s).  If, however, a one-time adjustment 

were granted just for the current year, the assumption is that the adjustment does not carry 

forward into the next year.  If the property owner then feels that the valuation is overstated in 

the following year, he/she must submit a new application.


What if I am not satisfied with the result of the abatement hearing?​


A property owner may submit an appeal to the Massachusetts Appellate Tax Board (ATB).  

Information for the Appellate Tax Board is available online by searching on