Example Calculation: Boston Downtown Condominiums

On a small, half-acre parcel of land located on Commonwealth Tidelands, a project owner has proposed a high-rise tower containing 175 condominiums, 20,000 SF of retail, and 90 units of underground parking. 75% of the site (15,000 SF) is located within 100 FT of the shoreline. 25% of the site (5,000 SF) is dedicated to open space. Downtown Boston corresponds to the “Downtown Boston” market context in the calculator.

Results and Analysis

  • The “proposed project” achieves about 192,500 SF of floor area overall and an estimated value of $23-25M
  • A legally permissible “comparison project” could only contain about 57,000 SF of floor area overall. Assuming a similar program of uses with parking scaled down proportionally, it would achieve a relatively low value of ~$5-$6M.
  • There is a large value premium of $14-$15M that the proposed project achieves over the legally permissible comparison project.

Figure 1. The scope and estimated land value of the proposed project exceeds that of the comparison project.

Given this discrepancy, the user has two options:

(A) Reduce the scale of the proposed project to fit maximum allowable footprint onsite.

(B) Approve the project as proposed, with the assumption that the project owner must either (i) offset the reduction in public access with onsite benefits or (ii) return compensation to the community in the form of a “financial mitigation” payment. The value premium of $14-$15M could be a source of this compensation back to the community.

Calculator Inputs

Basic Inputs

  • Total Site Area (square)20,000
  • Setback between Site Area and Shoreline0 FT
  • Tideland TypeCommonwealth Tideland
  • CityBoston
  • Market ContextDowntown Boston

Real Estate Assumptions

  • Building UseMixed Use
  • Residential rental units175
  • Office square footage0
  • Retail square footage20,000
  • Industrial square footage0
  • Hotel units0
  • Community space square footage0
  • Open space square footage5,000

Proposed Project Assumptions

  • Construction StyleHigh rise concrete & steel
  • Parking Construction StyleUnderground parking

Comparison Project Assumptions

  • Construction StyleHigh rise concrete & steel
  • Parking Construction StyleUnderground parking

Parking Assumptions

  • Residential Rental90 units