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10340 Democracy Lane

Pre-Application

Private Development · 10340 Democracy Lane, Fairfax, VA 22030 · topic history · city record ↗

280 units · 6 stories · 3.22 acres

Screening estimates. These figures rank likely magnitudes with stated assumptions and ranges — they are decision-support context, not predictions. Every number traces to a source or a named assumption in the appendices below. Formulas, citations, and limitations: methodology report (PDF).

In plain terms: the project would add roughly 479 residents and about $1.0M a year in new property tax, but serving those residents costs money too. Depending on how you count the cost of city services for new residents, that nets out anywhere between a net cost of about $1.6M a year and roughly break-even. The strict accounting (every resident carries a full share of today's citywide costs) gives the costlier figure; counting only costs that actually grow with new residents gives the friendlier one. The likely answer sits in between.

Where the effects land

Loading map…

The economic map shows total captured spending by business location and named reporting clusters. The walk map uses a tighter extent around walk-arriving capture and the street segments assigned new resident walk trips; the bike map (when present) shows bike-arriving capture across the city — bikes reach farther, so it spreads wider and thinner. Dollar heatmaps are clipped to CR (Commercial Retail) zoning, and each map is scaled to its own data, so colors are not comparable across maps.

Summary

The project at 10340 Democracy Lane proposes to rezone approximately 3.22 acres in the City of Fairfax from Commercial Retail to accommodate a six-story, up to 280-unit residential building with 458 structured parking spaces, replacing an approximately 59,983 square-foot office building with surface parking. This analysis estimates 252–272 new households and 378–598 new residents at stabilization, generating a real estate tax increase of approximately $1,009,000–$1,307,000 per year over the current site tax. The net annual fiscal impact spans a wide range depending on which cost method is applied: under the naive per-capita method (the upper-cost framing), the range is approximately −$2,643,000 to −$424,000 per year; under the marginal framing (the lower-cost framing), the range is approximately −$1,230,000 to +$1,066,000 per year. The three assumptions to which the net fiscal result is most sensitive are, in order: the assumed average household size for multifamily units (1.5–2.2 persons per unit), the student generation rate per unit (0.05–0.12 students per unit), and the marginal cost factor applied to non-school city services (0.25–0.55).


View metric methods and calculations →

Adjust the assumptions

Every estimate above rests on named assumptions with published ranges. If you have better local knowledge, move the sliders — adjusted values use the exact formulas of the pipeline, bounded by each assumption's sensitivity range. Travel and destination-choice parameters are excluded (they require a full model re-run). Nothing is saved or submitted.

Assumptions

Occupancy rate
0.95
0.9published: 0.950.97

share of proposed units occupied at stabilization

Household size (multifamily)
1.8
1.5published: 1.82.2

persons per occupied new multifamily unit for a typical studio/1BR/2BR mix

New-construction income premium
1.125
1published: 1.1251.25

new-construction multifamily rents draw higher-income households than the area median

Spending-survey scaling
1
0.85published: 11.15

CES line items are national averages; ±15% covers regional and vintage drift

Walk trips per resident per day
1
0.5published: 12

scales new residents into all-purpose daily walk trips for the foot-traffic flow allocation

Sq ft per office job
350
250published: 350500

existing commercial sqft -> displaced jobs; a higher value yields fewer displaced jobs per sqft

Sq ft per retail job
500
400published: 500700

proposed retail sqft -> on-site jobs

Assessed value per dwelling unit ($)
360,982.5
359,599.256published: 360,982.5458,932.463

median assessed value per unit across 3 apartment-class comps, 25th-75th percentile bounds

Retail value per sq ft ($)
275
200published: 275400

assessed $/sqft applied to proposed retail space; refine with commercial comps in a follow-up

Office value per sq ft ($)
300
200published: 300450

assessed $/sqft applied to proposed non-retail commercial space (office, medical, bank). Previously omitted, which valued every proposed office at zero

Students per unit
0.08
0.05published: 0.080.12

drives the school-cost component when the education transfer and enrollment are pinned (school-split cost model); otherwise informs the school note only

Marginal cost factor
0.35
0.25published: 0.350.55

share of the NON-school per-capita cost that scales at the margin (school costs follow the student estimate directly under the school-split model)

Vehicles per household
1.4
1published: 1.41.8

rough-estimate input: converts new households to taxable vehicles for the personal property levy

Assessed value per vehicle ($)
14,000
9,000published: 14,00020,000

rough-estimate input: average taxable value per vehicle; no project-specific fleet data exists

Requires a full model re-run

These parameters sit inside the travel/destination-choice model, so their effect on the results is not a simple rescaling — they cannot be adjusted live.

Walk-time decay (β)0.1 (0.050.15)
Walk share — neighborhood trips0.6 (0.40.8)
Walk share — comparison goods0.1 (00.3)
Walk share — grocery/entertainment0.3 (0.10.5)
Bike-time decay (β)0.1 (0.050.15)
Bike share — neighborhood trips0.02 (0.0050.05)
Bike share — comparison goods0.005 (00.02)
Bike share — grocery/entertainment0.01 (00.03)
Own-retail sq ft per equivalent business2,000 (1,5003,000)
Office gross receipts per sq ft ($/yr)500 (300800)
Business equipment value per sq ft ($)8 (415)
Share of on-site sales that is new to the city0.3 (0.150.5)
Restaurant share of ground-floor space0.5 (0.30.7)
Retail sales per sq ft ($/yr)400 (250600)

Recomputed estimates

Economic

MetricPublishedAdjustedΔ
New households266266
New residentsheadline479479
Aggregate household income$58.39M$58.39M
New annual spending: grocery$2.14M$2.14M
New annual spending: restaurant_bar$2.01M$2.01M
New annual spending: retail_comparison$2.57M$2.57M
New annual spending: retail_convenience$401k$401k
New annual spending: personal_services$584k$584k
New annual spending: entertainment$2.17M$2.17M
Annual capture: Fairchester Drive & Hill Street$2.48M$2.48M
Annual capture: Chain Bridge Road & North Street$2.05M$2.05M
Annual capture: Fair Lakes Parkway & Fair Oaks Mall$766k$766k
Annual capture: Mathy Drive & Pickett Road$625k$625k
Annual capture: Blenheim Boulevard & Fairfax Boulevard$504k$504k
On-site jobs removed (existing space)171171
On-site retail jobs added00
Net on-site job change−171−171
New annual spending arriving on footheadline$777k$777k
New annual spending arriving by bike$110k$110k
Implied spending per resident walk trip$4$4
New resident walk trips per day479479

Fiscal

MetricPublishedAdjustedΔ
Projected assessed value$101.08M$101.08M
Projected real estate tax$1.08M$1.08M
Real estate tax increaseheadline$1.01M$1.01M
Personal property tax on resident vehicles (rough estimate)$215k$215k
Meals tax on captured in-city dining$61k$61k
Local sales tax share on captured in-city retail$32k$32k
Annual school cost within the service-cost estimates$447k$447k
Annual service cost — naive per-capita method$2.96M$2.96M
Annual service cost — marginal framing$1.33M$1.33M
Estimated K-12 students22.422.4
Net annual fiscal impact — naive per-capita methodheadline−$1.64M−$1.64M
Net annual fiscal impact — marginal framingheadline−$5,714−$5,714
Net annual fiscal impact (range across both cost methods)−$823k−$823k

Adjusted values are exact recomputations of the model's central estimates for the assumptions above — the same arithmetic the pipeline runs, evaluated in your browser. Published ranges, maps, and the narrative report are not recomputed here.

Full analysis

Project description

The site is parcel 57 2 20 4E 001, located at 10340 Democracy Lane in the City of Fairfax, Virginia. It is currently developed with an approximately 59,983 square-foot office building with surface parking. The proposal, as described in the January 23, 2026 Project Narrative submitted by Capital City Real Estate (with Wire Gill LLP as legal representative), would rezone approximately 3.22 acres from CR Commercial Retail. The project narrative states the intent to develop approximately 260–280 residential units fully contained within a six-story building; this analysis records the maximum of that range, 280 units, per standard practice. The project proposes 458 parking spaces within structured parking, described as minimizing on-street and spillover impacts. No retail square footage, office square footage, affordable unit count, or residential tenure (for-sale versus rental) is established in the project documents; tenure is therefore unresolved. The project is in Pre-Application status as of the date of this analysis.


Economic effects

New demand. Applying an occupancy rate to the 280 proposed units, this analysis estimates 252–272 new households at stabilization. Multiplying those households by persons-per-multifamily-unit multipliers drawn from the Rutgers CUPR residential demographic multipliers (Listokin et al. 2006) yields an estimate of 378–598 new residents (central estimate: 479). Aggregate household income is estimated by multiplying the projected households by the mean household income for the site's Census tract 51600300200 ($195,124, from ACS 5-year 2024 tables B19025/B11001) and a new-construction income premium assumption, producing a range of approximately $49,171,000–$66,245,000 per year. Residential tenure is not established in the project documents; rental defaults are used for household size, occupancy, and the income premium. For-sale product would raise all three.

Spending by category is estimated by multiplying projected households by BLS Consumer Expenditure Survey 2023 line-item averages, scaled by income ratio raised to a category-specific Engel elasticity. The largest spending clusters are comparison retail (apparel, furnishings; approximately $1,848,000–$3,330,000/yr), entertainment (approximately $1,542,000–$2,842,000/yr), grocery (approximately $1,637,000–$2,639,000/yr), and restaurants and bars (approximately $1,465,000–$2,582,000/yr).

Where spending is likely to land. The Huff capture figures below are screening estimates. They are computed using a joint destination-and-mode-choice model (Huff model: P(j,m) ~ A_j × w_m × exp(−b_m × t_mj)) applied to individual retail points of interest, then aggregated to named commercial areas for reporting. They rank where new resident spending is likely to be captured; they are not predictions. The top two clusters by projected capture are:

  • Fairchester Drive & Hill Street: approximately $1,853,000–$3,272,000/yr, led by grocery and comparison retail.
  • Chain Bridge Road & North Street: approximately $1,315,000–$2,961,000/yr, led by restaurants and bars and entertainment.

Additional capture is estimated at Fair Lakes Parkway & Fair Oaks Mall (approximately $573,000–$865,000/yr), Mathy Drive & Pickett Road (approximately $476,000–$769,000/yr), and Blenheim Boulevard & Fairfax Boulevard (approximately $388,000–$643,000/yr).

The model estimates that 60–68% of all-retail spending and 63–74% of food-away-from-home spending would be captured at destinations inside the city boundary, with the remainder leaving to surrounding jurisdictions. These are also screening estimates subject to the same Huff model assumptions.

Project's own retail capture. The proposed project includes no retail square footage as established in the project documents. Accordingly, the project's own ground-floor retail capture is $0/yr and the model treats no on-site retail as a competing destination.

Foot-traffic index. The foot-traffic index change across the 10 nearest commercial street segments is estimated at +0.1% (relative index). This figure is a screening estimate computed by allocating the new residents' modeled walk trips as exact marginal flows (POI-weighted destinations, walk-time decay, shortest paths) against a sampled betweenness index of today's population. It is not calibrated to observed pedestrian counts.

Jobs ledger. The existing approximately 59,983 square-foot office building is estimated to support 120–240 on-site jobs (central estimate: 171), computed by dividing existing commercial square footage by an assumed square-footage-per-office-job. Because no retail square footage is proposed, on-site retail jobs added equals zero. The net on-site job change is therefore estimated at −120 to −240 jobs (central: −171). This reflects the displacement of estimated office employment; whether those workers relocate within the city, the region, or leave the workforce is beyond the scope of this analysis.


Fiscal effects

Current tax. The current real estate tax on the site (parcel 57 2 20 4E 001), computed as the current assessed value multiplied by the City real estate tax rate divided by 100 (FY2027), is $70,708/yr.

Projected real estate tax. Projected assessed value is estimated by multiplying proposed units by assessed value per unit drawn from three City of Fairfax apartment comparables built since 2011 (parcel 48 3 02 011 A: $360,982/unit, 400 units, built 2020; parcel 57 1 02 031 C: $359,599/unit, 403 units, built 2022; parcel 57 2 20 006 A: $458,932/unit, 268 units, built 2022). This yields a projected assessed value of approximately $100,688,000–$128,501,000. Multiplying by the City real estate tax rate divided by 100 (FY2027) produces a projected real estate tax of approximately $1,079,877–$1,378,174/yr. The real estate tax increase over the current site tax is approximately $1,009,000–$1,307,000/yr.

Other recurring revenues. The analysis includes three additional recurring revenue lines:

  • Personal property tax on resident vehicles (rough estimate): approximately $93,668–$403,815/yr, computed as new households multiplied by assumed vehicles per household, multiplied by assumed average vehicle assessed value, multiplied by the City personal property tax rate. No project-specific vehicle data exist; this is an order-of-magnitude estimate only.
  • Meals tax on captured in-city dining: approximately $41,785–$86,158/yr, computed as restaurant spending multiplied by the in-city capture share from the Huff model, multiplied by the City meals tax rate (FY2027).
  • Local sales tax share on captured in-city retail: approximately $22,643–$44,039/yr, computed as in-city captured retail spending multiplied by the local sales tax share (per Va. Code § 58.1-605).

Service costs — two methods. Two cost framings are computed and both are reported; the net fiscal range spans both on purpose.

The naive per-capita method computes cost as new residents multiplied by the non-school General Fund per capita ($5,254, derived from the FY2027 adopted budget: ($207,912,496 − $76,429,791) / 25,026 residents) plus estimated students multiplied by net local cost per pupil ($19,961, derived as ($76,429,791 tuition − $14,492,271 state education revenue) / 3,103 students). This produces a cost range of approximately $2,265,000–$3,810,000/yr. This method allocates fixed citywide costs to new residents and therefore overstates incremental costs for infill development.

The marginal framing computes non-school cost as new residents multiplied by the non-school per-capita cost multiplied by a marginal cost factor (0.25–0.55), on the premise that fixed services do not scale with additional residents. School costs are identical in both framings: estimated students multiplied by net local cost per pupil. The marginal framing produces a cost range of approximately $776,000–$2,397,000/yr. This method may understate costs if service capacity expansions are triggered.

School costs are the same in both framings: 14–34 estimated K–12 students (central: 22, computed as 280 units multiplied by a students-per-unit rate drawn from Rutgers CUPR high-rise multifamily multipliers) multiplied by $19,961 net local cost per pupil, yielding approximately $279,000–$671,000/yr.

Net fiscal impact. Combining the revenue lines with each cost framing:

  • Naive per-capita method: approximately −$2,643,000 to −$424,000/yr (a net cost under all modeled conditions).
  • Marginal framing: approximately −$1,230,000 to +$1,066,000/yr (spanning negative and positive depending on assumptions).

The combined range across both methods is approximately −$2,643,000 to +$1,066,000/yr. The naive per-capita method produces a consistently negative net because it distributes fixed citywide overhead to new residents; the marginal framing produces results straddling zero because it counts only costs that are expected to grow with additional residents. Neither method has been externally reviewed for this project. No external published fiscal estimates are available for comparison; the Council packet staff report dated 2026-07-28 contained no figures.


Not evaluated in this version

Analyses of bike-lane corridor effects, trail connectivity, broader multimodal connectivity, environmental impacts (stormwater, tree canopy, urban heat), and comparable-places benchmarking are deferred and have not been computed for this version of the report. They are not reflected in any figure presented above.

Method notes & caveats

  • Huff capture is a screening estimate computed per business location (every retail POI is an individual destination) and aggregated to named areas for reporting; it ranks where new spending is likely to land, with sensitivity bounds — it is not a prediction.
  • Residential tenure (for-sale vs rental) is not established in the project documents; rental defaults are used for household size, occupancy, and the income premium. For-sale product would raise all three.
  • The project's own retail is included as a competing destination; its capture estimates how much of the residents' spending the ground floor itself can hold on to.
  • Displaced use: Office building with surface parking (approximately 59,983 sq ft office building). Any spending that originated on-site today is assumed negligible relative to the new residential demand.
  • Bike-arriving capture models cycling as a third mode alongside walking and driving: the bike preference is taken from the drive remainder (walk shares are unchanged), and bikes reach ~3-4x the walking distance per minute of travel time.
  • Foot-traffic flows are exact allocations of the new residents' modeled walk trips; the % comparison uses a sampled index of today's walkers, not calibrated pedestrian counts.
  • Walk-in capture per business is the walk-arriving share of the NEW residents' spending under a joint destination-and-mode choice: walking competes with driving per destination, so businesses beyond practical walking range receive effectively none of it and the rest of the spending arrives by car. It is not total pedestrian commerce. Comparing a business's walk-in capture to its total capture shows how much of its projected gain depends on being within walking distance of the project.
  • Personal property tax is a rough estimate: the city rate is pinned, but vehicles per household and average vehicle value are assumptions, not observed data. Pinning per-household budget actuals would replace this estimate.
  • School costs use the split model: 22 students (14-34) x $19,961 net local cost per pupil ≈ $447,116/yr in both cost framings — a development generating fewer students carries proportionally lower costs instead of the school-heavy citywide average.
  • The net fiscal range spans both cost framings on purpose: the naive per-capita method overstates costs for infill (it allocates fixed citywide costs to new residents); the marginal framing understates them if service capacity expansions are triggered.
  • The revenue side includes the rough-estimate personal property and BPOL lines: leaving them at zero would understate revenue for taxes the city does levy, but both carry wide assumption-driven bounds.

Data sources

Computed Aug 22, 2026 · narrative by claude-sonnet-4-6 over deterministic model output (v3)