Community Resource Guide

table of contents


The Multifamily Housing Database (MFHD) was created with the goals of: i) automating the process of producing quarterly BIP reports, ii) standardizing the collection and storage of data on multifamily rentals in NYC, and iii) organizing the decade plus of historical data collected through BIP to make available for research and analysis. The MFHD allows for the possibility of a number of added elements to UNHP’s data work, including:

The ability to more easily compare trends over time in the decade-plus worth of data in BIP. This is especially relevant for analysis of pricing, speculation, and predatory tactics on the part of landlords, as our research has shown that speculative behavior is best grasped by examining multi-year patterns.

The ability to access more detailed information than has been traditionally maintained in our quarterly BIP excel files. For instance, while BIP currently only captures the count of active DOB violations, the MFHD will allow for storage and easy analysis of subsets of DOB violations that might be relevant to organizers or lenders.

The ability to quickly incorporate new datasets into the MFHD. Just this year, new and relevant datasets came onto the NYC Open Data Portal on subjects like eviction warrants executed or J-51 tax abatements. The code for the MFHD is easily adjustable in order to interact with new datasets, which allows us to migrate and provide access to new data in a format that is digestible for our users.

The ability to provide up-to-date data on buildings in the BIP database. Currently, we update and send out BIP data quarterly. However, the MFHD will update with any new data at regular intervals, and partners who prefer to see any changes in violation counts or financing data as soon as they occur can have access to that capability in a familiar Excel format.

The ability to serve as a back-end for other housing data tools. By virtue of UNHP’s long history collecting data and institutional expertise, the data tools that housing advocates and lenders use would benefit immensely from access to BIP data. The MFHD is structured using common data architecture, allowing academics, civic tech activists, and other stakeholders to access customized ‘slices’ of the data when appropriate.

Guide Summary

In this guide you will find a summary of the data structure used for the Building Indicator Project (BIP). The summary assumes that the reader has experience with the world of NYC housing data (particularly Open Data), and is intended to help users of the MFHD understand the potential applications of BIP data and their limitations. The data summary is divided into five parts:

1. Processed BIP Data – in this section, we lay out how the data sources that get automatically updated in our SQL Server are transformed into a format consistent with Building Indicator Project quarterly releases. This section focuses on key differences between pre- and post- implementation of the MFHD. We also provide descriptions of the source data used to arrive at BIP quarterly reports. In many cases, these source tables are already processed versions of the raw data that are available through NYC Open Data or the sites from which we scrape data. Those transformations are described.

3. Other Sources – in this section, we provide context for data sources not in BIP but of relevance to our users.

4. Data Management – in this section, we provide context on our management tables in the MFHD, as well as other data infrastructure that allows us to process and keep track of the data we collect.

5. Introduction to SQL Server – in this section, we provide a brief overview to SQL, including best-practices in constructing queries in the MFHD that produce results quickly and efficiently. 

How to Access MFHD SQL Server

In order to access the MFHD, you must request a username and password by sending an email to bip@unhp.org. The email should include a brief description of the intended use of the data. Please note that we do not provide access to the MFHD for for-profit uses, and do not have capacity to provide technical support beyond what is provided in the documentation in the MFHD Guide.