The Price of Staying: How Housing Affordability Has Changed Across the DMV

How has the cost of buying and staying in a home — home prices and estimated mortgage payments relative to household incomes — changed across the DMV between 2015 and 2025? Phase 1 (Working Paper 01) answers a narrower question for Washington, DC only: how did inflation-adjusted transaction prices (2015–2024) and illustrative mortgage payments (2015–2025) change for condominiums and residential houses? Northern Virginia and suburban Maryland will be studied in later phases.

Study period

2015–2025

Later years

Phase 1 compares real (CPI-adjusted) prices for 2015–2024 only, because annual 2025 CPI was incomplete in the extracted data; mortgage payments are nominal illustrations for 2015 and 2025. 2026 figures will be added only where they are available on a comparable basis.

• Area A

  Washington, DC

  Phase 1 — published. Working Paper 01 analyzes DC condominium and residential-house sales, 2015–2025. Sub-city detail only where sample sizes allow.

• Area B

  Northern Virginia

  Future phase — coming later. No Northern Virginia data has been analyzed or published yet. Proposed coverage: inner and outer Northern Virginia counties and independent cities; the final list will be documented before analysis.

• Area C

  Suburban Maryland

  Future phase — coming later. No Maryland data has been analyzed or published yet. Proposed coverage: Maryland counties bordering or near the District; the final list will be documented before analysis.

01Home prices

Phase 1: median DC transaction prices by segment, CPI-adjusted to 2024 dollars (2015–2024), plus fixed-basket size and bedroom checks. Later phases add Northern Virginia and suburban Maryland.

02Mortgage payments

Phase 1: modeled monthly principal and interest on a median-priced purchase, 2015 and 2025, with 20% down and a 30-year fixed loan at annual average Freddie Mac rates.

03Household incomes

Later phases: median household income by jurisdiction from the Census ACS. Not used in Phase 1.

04Affordability ratios

Later phases: payment-to-income and price-to-income comparisons once income data is added. Not yet studied.

1. Question 1

   Phase 1 (DC): Did condominium and residential-house prices follow different real paths between 2015 and 2024, and does that hold after fixed-basket size and bedroom checks?

2. Question 2

   Phase 1 (DC): How much of the change in illustrative monthly payments between 2015 and 2025 reflects higher rates rather than higher prices?

3. Question 3

   Later phases: Did Northern Virginia and suburban Maryland follow different affordability paths from DC? (Not yet studied.)

4. Question 4

   Later phases: Do local transaction records and index-based measures such as the FHFA HPI point in the same direction? (Not yet studied.)

5. Question 5

   Later phases: How did prices and payments change relative to household incomes from the Census ACS? (Not yet studied.)

1. 1

   Step 1: Collect DC transactions

   Phase 1: candidate qualified sales dated 2015–2025 from DC CAMA records via Open Data DC (80,985 sales).

2. 2

   Step 2: Match to current assessment records

   Phase 1: link each sale by its SSL identifier to the current CAMA residential and condominium tables; about 96% matched, 3,217 unmatched sales excluded.

3. 3

   Step 3: Segment

   Phase 1: classify sales as condominiums or residential houses using the current assessment snapshot, not classification at the time of sale.

4. 4

   Step 4: Adjust for inflation

   Phase 1: convert prices to 2024 dollars with annual BLS CPI; real comparisons end in 2024 because annual 2025 CPI was incomplete.

5. 5

   Step 5: Fixed-basket checks

   Phase 1: hold the 2015 mix of unit sizes or bedroom counts constant, using cells with at least 30 sales, to limit composition effects.

6. 6

   Step 6: Model payments

   Phase 1: estimate principal and interest for 2015 and 2025 median-priced purchases under stated loan assumptions.

7. 7

   Step 7: Read against benchmarks

   Phase 1: compare with the FHFA House Price Index as context, and verify data definitions with the DC Office of Tax and Revenue.

8. 8

   Step 8: Extend to the region

   Later phases: repeat the workflow for Northern Virginia and suburban Maryland and add household incomes. Not yet started.

• Phase 1: Property type is assigned from the current DC CAMA assessment snapshot, not classifications at the time of each sale.
• Phase 1: Sales are candidate qualified; the meaning of the 'Q' qualified code is still being verified with the DC Office of Tax and Revenue, so sales are not proven arm's-length.
• Phase 1: Median transaction prices are not repeat-sales appreciation. Fixed-basket checks limit some composition effects but do not control for neighborhood, condition or renovations.
• Phase 1: Mortgage payments are modeled examples (20% down, 30-year fixed, annual average Freddie Mac rates) and exclude taxes, insurance, HOA fees, maintenance and closing costs.
• American Community Survey estimates carry sampling error, and standard 1-year estimates were not released for 2020.
• Freddie Mac PMMS reports national average rates; local borrowers may face different rates.
• Coverage and licensing of local transaction data vary by jurisdiction and may limit which places can be compared in later phases.
• This series focuses on purchase affordability. Renter costs may be covered in a later installment.