Monday, December 1, 2014

New York City Class 1 Average Property Tax Payment by Zipcode source: NYC DOF Assessment

New York City Class 1 Average Property Tax Payment by Zipcode source: NYC DOF Assessment

2014 New York City Class 1 Tax Burden
See interactive map

Based on the  New York City Department of Finance Assessment Data this study focuses on Class 1 property (Residential Properties for less than 4 families)

The red areas pay $8000 or more in property tax.  The blue areas pay $2100.  

A companion map that shows assessment ratio can be seen here: and details here

These two maps show the areas that are paying relatively low property tax vs. relatively high property tax.

The Assessment Ratio map shows the areas that are assessed below 6% and these areas will slowly rise to 6% over many decades due to current tax law
Tax Assessment Ratio map
Points of interests are:

  • Manhattan Class 1 property owners are paying on average up to $80K in property tax, but the assessment ratio is low so it will continue to rise very slowly over the next decades. 
  • The Park Slope area of Brooklyn's Class 1 property owners are paying very low property tax in real dollars on average relative to almost every other area and also have a very low assessment value and assessment ratio.  This is unique to Park Slope and the immediate surrounding area.
  • It is interesting to note that residents that are badly affected by plane noise nearby LaGuardia airport and JFK airport such as Whitestone Queens and parts of Rockaway Queens pay a large tax burden on average and also have a very high assessment ratio
To make it easier to see the tax burden vs. assessment ratio we allow you to see them on a similar map and style here:
  • Class 1 Tax Payment Property: map link
  • Class 1 Tax Assessment Ratio Property: map link
2014 New York City Class 1 Tax Burden
2014 New York City Class 1 Tax Assessment Ratio

Friday, October 24, 2014

Civic Minded Computer Programmers Please fork this repository

We should all thank Ben Kallos (a New York City Councilperson) for his forward thinking and his ability to say and do things that he believes in.


This is a place where we can re-build law from the ground up -- which is the way to build any stable structure.

Please fork it, change it and issue pull requests.

Wednesday, October 22, 2014

2014 November New York State Ballot Proposals

Please everyone read and prepare for the New York State Ballot proposals.  Even though we in New York State have no direct initiative process and even more surprising, we seem to give almost no attention to our existing ballot proposal system, we still recommend that you read to understand the very weak democracy in action in New York State.  Please read and understand the ballot proposals BEFORE going in to the voting area.

I recommend that you discuss this with your peers and in groups and everywhere.

While you are at it, ask yourself "WHY does New York State NOT have a direct initiative process, similar to Switzerland and most US Western States?"

Monday, October 13, 2014

Do you want to see your New York City Council Hearings?


This is a very old and not mobile friendly site.

But it holds all your tax dollar funded new york city council hearings

Please contact your city councilperson and ask that they move to a better mobile friendly video hosting.

Please contact your state and city representatives

See the eye test:  (yes this is the mobile site for our city council.  Unreadable!)

Android Wear Workshop coming up Date: Sunday Oct 19, 9am-5pm Place: Google's New York office

Go to to apply to attend

At this one day code workshop event, you will have personal help from a Google expert, Lisa Wray, to Wear-enable your existing Android app. Please arrive with your app in your IDE ready to go, the wearable SDK installed, and your laptop.

You will receive an invitation via email if your application is selected. We are looking for experienced developers who can benefit the most from a Google expert. We especially encourage you to apply if you have an app in the Google Play store.

Date: Sunday Oct 19, 9am-5pm
Place: Google's New York office

Saturday, October 4, 2014

mayor deblasio "sings" (sic) bills?

Please take a look at

It appears our mayor is also a "singer (sic) of bills"

Plus the video and audio appears to be completely incoherent.

It appears that our council will legislate next that you must be polite to everyone you meet and there will be a civil penalty for impoliteness.

This "mutual admiration society" in our city government must end.  And if not, any person with the means and intelligence will leave New York City.  Please everyone consider running for mayor for the next election.  And if you cannot, speak to your associates and neighbors.  Please create "political clubs" etc.  We need to get more involved!

Friday, September 19, 2014

New York City Comptroller Data (compstat, claimstat, or missingstat?)

The New York City Comptroller in 2014 announced ClaimStat with great shouts.

Here we take the data from the comptroller's page and run some statistical analysis.

We also ask the question, "where is the property damage claims data?"

For claims data, see police damage claim data and tree damage claim data 

How long to you believe on average does it take for our New York City Comptroller to settle a police related claim?  

It turns out that on average it takes 319 days.

The average settlement is for $16K

See the statistics below:


min_date_settled1/15/2013 0:00:00
max_date_settled6/27/2014 0:00:00

See to access the claims data in a SQL database

Access to the statistics sheet:

Wednesday, September 17, 2014

Your Community Money allocated by your New York City Council on a Map

Your Community Money allocated by your New York City Council on a Map.

Use this application to see where your tax money is going.

Go to

Money to representative Cornegy

Money to representative Deutsch

Top 40 expenses

Tuesday, September 16, 2014

What is Assessed Value? Or why does your property tax bill go UP when the property tax rate goes DOWN?

We realize that this defies even the most elementary of mathematics, but if the property tax rate goes down, why does the amount you pay go up?

Our representatives are very proud to say that the Class 1 property tax rate went down, what they do not say (and may not even be aware) is for most property owners the amount you will pay will go up, NOT down. Some may say that "oh, this is inevitable" But it is not.

Howard Jarvis used to say that if we are being badly served by politicians, it is our fault. We voted them in and we can vote them out, he would remind voters.
Some may not believe their individual vote is important, but by working in concert with other voters, we will make the difference between a future of debt and desperation, and one of prosperity and opportunity. source:
It is very simple, some of the premises of the New York City budgeting process are:
  • "all numbers must increase by 4% to 6% to show improvement and growth"
  • "All New York City agencies want to show improvement and growth"
  • "New York City budget is made up of numbers"
  • a growth of less that 4% to 6%, is actually a cut in the agencies view.
Imagine that if the growth is 3% then the agency considers that a 1% to 3% cut.  This is a troubling trend and mindset that should be re-considered.

We highly recommend that every citizen watch the budget process in our New York City Council.  Watch every minute of it.

It is very clear that some of the council members may not understand the assessment process.   

The assessment process was passed in 1981 see this report  and see this newspaper

Overriding the Veto. On December 3, 1981 the Legislature met to vote on the override. The measure passed easily in the Senate. In the Assembly, Minority Leader James Emery, an upstate Republican who was running for Governor, pressured some of his colleagues to abandon their initial opposition to the bill and support the override. Although the Minority Leader himself did not vote for the override, he succeeded in convincing others. When Assemblyman George Winner of Elmira first walked into the chamber that night he declared his opposition to the override. Later, he said, “Into the tank,” and switched his earlier vote, as did 13 Republican colleagues, and joined the Assembly’s Democratic majority in overriding the Governor’s veto by three votes. At 9:55 p.m. the road to adopting S7000A had been completed.
This law which is referred to as S7000A passed by only three votes to override the veto of then Governor Hugh Carey.

It is time now, 33 years later, for a New York City and State property tax modernization act.

If you want to see how much you are over or under paying in your property tax when compared to the average see

Consider Proposition 13 in California.  We are taught that California is not well run.  But we ask why?
  • California voters can bypass the legislator and pass and amend laws.
  • California voters vote on important issues.  Consider our elections in New York State where we have no choice at all. In fact, in New York City the mayor and legislature can bypass a referendum of the people.  See this well written report where Bloomberg overrode the people and the council voted for it's own pay raise and term extension.  Surely, this type of action should be unconstitutional. 
  • California property tax assessment is based on your purchase price of your home.  This means it is under your control.  NOT under the control of arbitrary laws that was decided more than 30 years ago that most assessments have to go up 4% to 6% every year.
Ask yourself who benefits from the constant increase of 4% to 6%?

Compare your property tax payment to the average and to other properties

If you'd like to compare your property tax for Class 1 homes in New York City, go to

Many thanks to our New York City Department of Finance for supplying this data.
See and

Friday, July 25, 2014

The Williamsburg Bike Path is very dangerous

Since February 2014, cyclists have endured a NYC DOT caused pothole filled bike path.

The history is that the bike path was in very bad shape, but the DOT project started in February 2014 cut large squares which you can see in the pictures.  They exposed the bare metal which becomes very slippery when wet.  This has caused many accidents including the author.


Those squares on DOT created dangerous potholes

Please contact your state and city representatives and refer to this article and ask for a safe bike path.  Where is Vision Zero?  The grade for this DOT project is ZERO!  Hopefully, that is not what we mean by Vision Zero!

Friday, July 11, 2014

A modest proposal for New York City Class 1 Property Equity $400 Million overpaid

To check if you are overpaying your New York City Property Tax (currently for Class 1 properties only) see this application and this application (initial release/older version)

Using the published data from  our New York City Department Of Finance ( we will propose a plan for a revenue neutral change to the assessed values across all Class 1 properties to make the assessment ratio equal as required by our NY State Constitution.

Currently we have assessment ratios for Class 1 properties that varies from less than 1% to 6%.  This is obviously unequal.  1 is not equal to 6. :(  This is obviously true. :) The reason your property is assessed at a higher value than another property with a much higher market value is an arbitrary quirk of how the real property tax law was written See this report

The plan to is to modify the current assessment ratio from its current wide range to one value.  The value is taken from the current data in order to make the change "revenue neutral".  The new value for the assessment ratio is 4.6%

Therefore, those Class 1 properties assessed at higher than 4.6% will be lowered to 4.6% and those below 4.6% will be raised to 4.6%.  4.6 IS equal to 4.6.  This is also obviously true. :)

The shift of property tax payments will be $400 Million.

In other words, there are  470,633 property owners who, as a group, are overpaying $400 Million and there are  191,047 property owners who, as a group, are underpaying that same $400 Million.

For details see:

Wednesday, July 2, 2014

Play TicTaxToe and learn about the New York City Property Tax system

Here's your opportunity, you can play TicTaxToe and learn about the New York City Property Tax system.

Go to

Yes you read correctly Tic Tax Toe, not Tic Tac Toe :)

Saturday, June 21, 2014

NYC Property Tax Bill Comparison between Queens and Park Slope Brooklyn

We've already seen in that if you take the Assessed Value and divide by Market Value for NYC Properties according to NYC Department of Finance that certain areas such as Park Slope Brooklyn pay around 1% to 2% (that is, the assessment ratio (assessed value / market value) is around 1 to 2 percent).  And Queens, the Bronx, Staten Island, and parts of Brooklyn pay around 5% to 6%.

Now we plot the actual property tax bill amount and we focus on Class 1 Property.  You might think that, at the very least, in absolute dollar amounts places, such as Park Slope Brooklyn, would pay more per property since the market values per property are much higher.  You might think that, but you would be incorrect.

The truth is Park Slope and Queens pay about the same in property tax in dollars.


Park Slope:


Here is the averages based on data from NYC Department of Finance:

Here is similar data (NYC Property Tax Bill and Assessment Ratio by postal code ordered by Assessment Ratio):

Saturday, June 14, 2014

New York State Elections Voted Per Registered Voter by County

If you take the current New York State Voter File and divide the number of elections voted in the voter file by the number of registered voters and group by county. This is the result:
It appears that registered voters vote in more elections in the Buffalo and Albany area OR those areas have more elections.


Friday, June 13, 2014

Access the New York State Voter File

If you would like to analyse all the recent voting history and registration records for all New York State registered voters go to and fill out the form and submit. Within days you will receive a DVD containing a zip file which in turn contains two files.
  • AllNYSVoters.txt
After looking at it, it appears that there are a fair number of errors.

For example, according to the data, it appears, an 183 year voted in an 2013 election.  And that is only the start of the issues.


Sunday, June 8, 2014

NYC Tax Assessment Ratio for our public representatives

For those that do not know the NYC Property Tax system is very simple.  Please do not allow public representatives to tell you that it is very complicated and if they do, ask them what do they mean.

The complexity is in changing our property tax system to make it more equally applied.  As in the phrase "nor deny to any person within its jurisdiction the equal protection of the laws".  If this phrase sounds familiar it is because it is the ending text of our 14th Amendment to our US Constitution.

Also from our New York State Constitution: The legislature shall provide for the supervision, review and equalization of assessments for purposes of taxation. Assessments shall in no case exceed full value. (see

From our New York State Department of Taxation and Finance: Equalization rates do not correct unfair assessments within a municipality.

Equalization rates measure the level of assessment for the entire municipality. They are not intended to correct unfair individual assessments in a city or town. The assessor has the primary role in ensuring the fairness of individual assessments. The more frequently properties are reassessed based on current market values, the more likely it will be that assessments are fair. Property owners also have a role to ensure their individual assessments are fair.

Here's a spreadsheet that shows current and past public representatives and their property tax assessment ratio.  The property tax assessment ratio is the property total assessed value  divided by the property total market value.  It is by law set at 6%.  But you'll see that it is rarely 6% unless you live in Queens and the Bronx and Staten Island (this is shown in the data)

Sunday, June 1, 2014

New York City Property Tax: Largest Increases by percentage (Class 1 only)

Here's a list of Class 1 properties in New York City where the assessed value is increased by the largest percentage.

The assessed value directly affects the property tax paid by these properties and their owners.

Direct document link:

Direct spreadsheet link:


To access the source data in a format that can be queried directly see:

The query used to generate this data:

select (max(fn_avt)-min(fn_avt))/min(fn_avt) percentdelta, max(fn_avt), min(fn_avt),SOA.nm_recipient_1,SOA.nm_recipient_2,SOA.AD_NAME_ATTENTION,SOA.ad_street_no,SOA.ad_street_1,SOA.ad_street_2,SOA.AD_CITY,SOA.CD_ADDR_STATE,SOA.CD_ADDR_ZIP,SOA.AD_STREET_NO_PROP,SOA.AD_STREET_1_PROP,SOA.AD_CITY_PROP,SOA.CD_ADDR_STATE_PROP,SOA.CD_ADDR_ZIP_PROP,boro,block,lot from [nyc.assessment] ASSESS join each (select nm_recipient_1,nm_recipient_2,AD_NAME_ATTENTION,ad_street_no,ad_street_1,ad_street_2,AD_CITY,CD_ADDR_STATE,CD_ADDR_ZIP,AD_STREET_NO_PROP,AD_CITY_PROP,CD_ADDR_STATE_PROP,CD_ADDR_ZIP_PROP,AD_STREET_1_PROP,id_boro,id_block,id_lot from [acris_nyc.nyc_dof_SOA]) SOA on ASSESS.boro = SOA.id_boro and ASSESS.block = SOA.id_block and ASSESS.lot = SOA.id_lot where ASSESS.owner like '%'  group by boro,block,lot,SOA.AD_STREET_1_PROP,SOA.nm_recipient_1,SOA.nm_recipient_2,SOA.AD_NAME_ATTENTION,SOA.ad_street_no,SOA.ad_street_1,SOA.ad_street_2,SOA.AD_CITY,SOA.CD_ADDR_STATE,SOA.CD_ADDR_ZIP,SOA.AD_STREET_NO_PROP,SOA.AD_CITY_PROP,SOA.CD_ADDR_STATE_PROP,SOA.CD_ADDR_ZIP_PROP order by percentdelta desc

Direct document link:

Direct spreadsheet link:

Sunday, May 11, 2014

GDG growth over time and space :)

#gdg #io14 #photo

See for a preliminary visualization of GDG  - Google Developer Group ( attendance over time and space.

The size of the bubble relates to the number of attendees for that particular GDG meeting.

Note: the numbers are preliminary :)

Thursday, May 8, 2014

Wednesday, May 7, 2014

2014 Brooklyn Businesses that Lost Tax Exempt Status

Here it is: a map of 2014 Brooklyn Businesses that Lost Tax Exempt Status.


Thursday, May 1, 2014

Map of some FAA Five Letter Location Fixes

Does anyone know where all the FAA 5 Letter Location Fixes exist for download?


This seems to be a subset of the entire set.

Zoom out to see more locations.

Presentation at Civic Meeting (BetaNYC) about Property Tax Analysis and Reform

Friday, April 25, 2014

New York City Class 1 Property Tax Assessment Ratio Map by Zipcode

The Assessment Ratio is the Assessed Value divided by the Market Value.
Yellow is low and Purple is high.

It appears Park Slope and surrounding areas and others lead the list in paying the lowest property tax assessment ratio.

For access to a query ready data see

For the original in Microsoft Access format see

Wednesday, April 23, 2014

Steps to load New York City Property Tax Data into BigQuery

These are the steps to load New York City Property Tax Data into BigQuery

Update2: here's a direct link to the New York City Department of Finance FY 2015 Tentative Assessment Roll (FY15 Database Files by Tax Class (revised 1/15/14))
You will need a google account and a project with BigQuery enabled. See
The cost is very low, so far with millions of records loaded and 100's and 100's of queries the cost has been 1 cent.  Another very cool thing is you can make your data public to all authenticated users and the users accessing your data do so at no cost to you.

Update: Many Thanks to +Felipe Hoffa for pointing out that I can make the New York City Department of Finance FY 2015 Tentative Assessment Roll (FY15 Database Files by Tax Class (revised 1/15/14)) public.  So that is what I did.  You can sign in to BigQuery and run queries such as:
(Query to show for market value greater than or equal to 10 Million what is the sum of assessment values / sum of market values:)
    • SELECT '>=10000000',count(*),sum(fn_avt)/sum(new_fv_t) FROM [personal-real-estate:acris_nyc.nyc_dof_tc_Tentative_Assessment_Roll] where txcl='1' and new_fv_t >= 10000000
    • Answer at this point in time is 3%
    • While for < 10000000 it is 4.6%
    • A very regressive tax.  The lower market home pay a much larger tax as a percentage of market value.

This example focuses on Class 1 property but applies to all classes.

  • Download Data: 
    • wget

  • This contains a mdb (microsoft access file)  (not exactly an open standard)
  • If you're using unix, you can install mdb-tables and mdb-export
  • Extract Data to CSV format:
    • mdb-tables TC1.mdb
    • mdb-export TC1.mdb tc1 >tc1.csv

  • Load into BigQuery:
    • bq load --project YOUR_PROJECT_NAME YOUR_DATASET.nyc_dof_tc_Tentative_Assessment_Roll tc1.csv EX_COUNT:float,CUREXT_A:float,TN_EXL:float,DELCHG:string,BORO:integer,EXT:string,TN_EXT:float,NOAV:integer,FN_EXT_A:float,FN_EXL_A:float,APPLIC2:string,CUREXL_A:float,CONDO_S3:string,CONDO_S2:string,CONDO_S1:string,YRB_FLAG:string,PROTEST:string,TN_AVL_A:float,AP_TIME:float,COMINT_B:string,ZIP:float,NEW_FV_L:float,NEWLOT:integer,BLDGS:string,COMINT_L:string,NEW_FV_T:float,O_AT_GRP:float,NODESC:integer,YRA2_RNG:float,COOP_NUM:float,BLD_VAR:string,REUC:string,YRA2:float,YRA1:float,DROPLOT:integer,LIMIT:string,CP_DIST:string,CUR_FV_L:float,TXCL:string,CURAVL:float,L_ACRE:string,O_LIMIT:string,CUR_FV_T:float,BLOCK:integer,CURAVT:float,DCHGDT:timestamp,TN_EXT_A:float,AP_BLOCK:float,APPLIC:string,CORCHG:integer,HNUM_LO:string,AT_GRP:float,CHGDT:timestamp,TN_EXL_A:float,APTNO:string,EX_CHGDT:timestamp,GEO_RC:integer,FCHGDT:timestamp,STATUS1:integer,DISTRICT:string,STATUS2:integer,TN_AVT_A:float,FN_AVT:float,VALREF:string,CONDO_NM:float,GR_SQFT:float,CUREXT:float,O_TXCL:string,CORNER:string,RES_UNIT:float,CUREXL:float,EASE:string,CP_BORO:string,YEAR4:float,FN_AVL_A:float,CONDO_A:string,BLDGCL:string,MBLDG:string,STR_NAME:string,YRB:float,FV_CHGDT:timestamp,FN_EXT:float,AP_LOT:float,BFRT_DEC:float,AT_GRP2:float,FN_EXL:float,IRREG:string,TN_AVT:float,AP_BORO:string,FN_AVL:float,LND_AREA:float,O_PROTST:string,OWNER:string,YRB_RNG:float,SM_CHGDT:timestamp,BBLE:string,SECVOL:float,BDEP_DEC:float,TN_AVL:float,O_APPLIC:string,LOT:integer,CURAVL_A:float,LDEP_DEC:float,YRA1_RNG:float,CURAVT_A:float,PROTEST2:string,FN_AVT_A:float,STORY:float,ZONING:string,HNUM_HI:string,EX_INDS:string,LFRT_DEC:float,CBN_TXCL:string,AP_DATE:timestamp,TOT_UNIT:float,EXMTCL:string,AP_EASE:string

  • A sample query would be:
    • for market value greater than or equal to 10 Million what is the sum of assessment values / sum of market values?
    • SELECT '>=10000000',count(*),sum(fn_avt)/sum(new_fv_t) FROM [YOUR_DATASET.nyc_dof_tc_Tentative_Assessment_Roll] where txcl='1' and new_fv_t >= 10000000

Friday, April 18, 2014

NYC Class 1 Property Tax Trend as Market Value Changes

What happens when you group Class 1 property by Market Value and then compare how they are assessed for property tax payment.  You will see that at >$0 market value the assessed value over market value ratio (we will call this the "assessment ratio") in 2014 is 4.6% and at the other extreme < $30 million the assessment ratio again is 4.6%.  This is obvious because both groups contain the majority of properties.   Although not all because there is currently at least 23 class 1 homes with a market value of greater than $30 million.

An interesting part is when you vary the break point.  You'll see that all homes over $3 million have an assessment ratio of around 3% on average while all homes under $3 million have an assessment ratio of 4.7% which means the lower market value homes are paying a higher tax percentage relative to their market value.   

Monday, April 14, 2014

New York City Area Road Tolls lead the Nation


That large fog is our area's leading tolls.

Where is all the Port Authority of New York and New Jersey Toll money going?

Friday, April 11, 2014

What are the typical ways we name our roads in New York City?

Is it a street, avenue, circle, etc?  According to Department of Finance data, it is shown here:

Could 1 Billion Dollars of New York City Property Tax be missing?


For Tax Class 1 properties, it appears that the sum of the Market Value is approximately $384 Billion but the assessed value should be 6% of the Market Value for Class 1 properties.  That would be (384 * 6%) = $23 Billion.  However according to the New York City Department of Finance the sum of the assessed values is approximately $18 Billion.  What happened to the other $5 Billion?  Ask your representative, this means that $1 Billion in property tax is not collected every year in Tax Class 1 property alone.

This does not even consider the other property tax classes.  However, we do see that Class 2 and 4 properties do pay the vast majority of property tax based on their assessment values.

New York City Tax Class Summary

Monday, April 7, 2014

Making Sense of the New York City Property Tax Assessment Information and Law

If you've ever tried to make sense of the New York City Property Tax Assessment Information, you would know that the information has evolved over a long period of time.  And just as barnacles attach themselves to a ship,  special interest laws attach themselves to our property tax system.  Here is the process:

“If you clean a ship or put a new ship to sea, it’s coated with microbes within a day,” said Van Mooy. “Not enough to see, but the first microbes are starting to lie down. And then the slime begins to grow over the course of weeks. That is essentially a gateway community to the barnacles and other things.”
“The slime” is a biofilm, a thin sheet of bacteria that stick to each other and to a matrix of molecules they exude to communicate with each other and to provide a hospitable environment for themselves. Once the slime forms, the rush is on, as algae and the larvae of creatures such as barnacles attach and begin to grow.

Well here is a tool to try to extract the ship from the slime.


presentation link:

Monday, March 31, 2014

Compare your New York City Property Tax Percentage to public or past public officials

Go to and compare the amount of tax percentage you pay to public and past public officials.

Here's an example:

This shows that HASHMI, TAHMINA K is paying 6% (assessed value/market value) when our current mayor DeBlasio is paying 1.4%

When you compare the percentages in a pie chart it shows this:


Sunday, March 30, 2014

The Inequities of the New York City and New York State Property Tax Law

We, as citizens of our society, may assume that, at the very least, the property taxes we pay would be based on the market value of our home. And those that purchase homes for many $1 millions would pay the same percentage as those that pay much less than $1 million.

You might assume that, but you would be incorrect.

Thanks to Regarding New York State Real Property Tax § 1805. See$RPT1805$@TXRPT01805+&LIST=LAW+&BROWSER=BROWSER+&TOKEN=42288330+&TARGET=VIEW)

The property tax cannot grow more than 20% in a 5 year period and not more than 6% in one year.  But there are exceptions.  For example, you legally repair your home.  Your repairs will go directly into your assessed value and your tax payment can rise much more than 20%, in fact it can rise many 100%'s in one year.

Here are realistic examples:

Case 1: $500K Home

A family buys a home that has been legally renovated.  This property is a two family home and is therefore considered a class 1 property. The current market value is $500K.  The current assessed value is $30K (6% of the market value).  The current tax bill is $5757.30 (.191910*$30000)

Now comes the change.  Because the home was legally renovated, there will be a "Cost Affidavit" submitted to the Department of Buildings.  The Tax Commission and the Department of Finance will add that Cost Affidavit directly to your market value.  In this case the cost affidavit (the cost of renovation) is $300K.

The new market value is $800K.  The new assessed value is $48K (6% of the new market value).  This is a 60% increase.  But wait the Real Property Tax § 1805 says the increase cannot be more than 6% per year.   But there is an exception in the law for improvements.  Therefore, if you improve your home your tax bill will increase in proportion to the improvement.  For class 1 property the tax increase in 2014 would be "$ of Improvement Value" * 6% * 19.191%.  

Read it for yourself:
5. Nothing in this section shall prevent placing on the assessment roll new property, additions to or improvements of existing property or formerly exempt property or the full or partial removal from the roll of property by reason of fire, demolition, destruction or new exemption and such increase or decrease in value shall not be included in the computation of the limitations prescribed by this section. Any parcel which would be assessed at a greater amount but for the provisions of subdivision one or two of this section shall be excluded from any survey or computation made by any body or officer for the purpose of determining a level of assessment to be used in the administrative or judicial review of assessments including, but not limited to, class ratios computed pursuant to paragraph (b) of subdivision one of section twelve hundred two of this chapter, ratios computed by selection of parcels or from actual sales of real property under the provisions of subdivision three of section seven hundred twenty of this chapter, and residential assessment ratios computed pursuant to section seven hundred thirty-eight of this chapter, but not including state equalization rates or class equalization rates. In the event that a parcel appearing on the assessment roll completed in nineteen hundred eighty or any subsequent

Case  2: $1 Million Home 

This home is class 1 and it's current market value is $1 Million.  If there has been no past limit on assessment value increases, then the assessed value would be $60K.  But in this case the New York State Real Property Tax § 1805 limited the assessment value increase to $24K (already this shows the inequity of the tax assessment limit law)  The ratio of $24K to $1Million is 2.4% and not the 6% that is instructed by law.  But we continue, a person buys the home for $2 Million.  Surely the new buyer would expect the market value and the assessment value to increase proportionate to the increase in purchase price.  Clearly the purchaser just bought the home for $2 Million which appears to show an ability to pay an equal share in tax.  But no, the tax limit increase law is in effect for purchases  AND NOT FOR IMPROVEMENTS!  WHICH STRAINS CREDULITY!  Therefore, this purchaser will not see a large increase in taxes paid instead will only see at most 6% increase in a year and 20% increase in a five year period.  And since this home was already affected by the limit it will take 41 years for the proper increase to reach the bill.  

Actual Market Value = $2Million

Billable Assessed Value = $24K
Actual Assessed Value (should be 6% of Actual Market Value) =   $120K

Using the principle of compound interest to increase $24K to $120K at a yearly growth of 4% will take 41 years.  4% is 20% / 5 years and is an approximation of the growth.  In practice, the growth is sometimes slower and therefore the proper tax would take even longer to reach the owner.

The appropriate property tax should be $23,029 but instead this owner pays only $5K

So our homeowner that repairs his home with a 60% investment sees his tax bill go up by 60%,  but a homeowner that increases the market value of his home by 100% sees only a 4% to 6% increase.  

This change to Case 1 is cumulative since the tax bill comes every year.

If you want to see a list of properties and owners that are paying very small percentage of tax because their assessed value is much below the 6% ratio of assessed value to market value maintained by law.  See

The most important fact in the spreadsheet is the ratio of assessed value over market value.  This is capped at 6%.  You are probably paying/assessed close to 6% while others are paying/assessed much less than 6%.

Some of the lowest are practically 0.  Some of these are government buildings but NOT ALL.