Whitemarsh's planning report puts the rehabilitation of the Abolition Hall buildings at $5.7 million to $7.1 million over two phases

Whitemarsh Township's architect for the Corson Tract, Mark B. Thompson Associates, puts the cost of turning the tract's three historic buildings from houses into public program space at $5.7 million to $7.1 million, in two phases of construction. The figures come from the firm's Assessment and Preliminary Planning Report, dated June 17, 2026, which the township attached to the agenda for the October 27 meeting of its Abolition Hall Steering Committee. The first phase, $905,000 to $1.1 million plus items the township would handle itself, carries a target schedule of fall 2026 through 2027. The second, $4.8 million to $6 million, is targeted for 2028 or 2029 and depends on a capital campaign.

The same agenda lists an update on a bid approval for invasive species removal, naming Stonewood Landshaping, Inc. and a $174,100 project, and a request to apply for a 2026 LSA grant, as the agenda names it, for some of the building and property improvements the report lays out.

The Corson Tract is 10.45 acres at Butler Pike and Germantown Pike in Plymouth Meeting, inside Whitemarsh. The township bought it in 2022 with the Whitemarsh Art Center, with support from the Karabots Foundation, and became sole owner in 2025, the report says. It holds the Hovenden House, the Maulsby Barn and Abolition Hall, where, according to the report, the Corson family hosted antislavery speakers before the Civil War.

The estimate by phase

Every first-phase line tops out at $500,000 or less

The report gives each piece of work a rough order of magnitude range, an early budgeting number set before any design or cost estimate. The first-phase lines depend on available funding, the report says. Envelope repairs and the Hovenden House apartment are marked “contractor proposals to be solicited.”

The first phase covers exterior envelope work on all three buildings: prioritized masonry and exterior wood repairs, chimney repairs and moisture control in the Hovenden House basement, and the structural engineering analyses the assessment recommends. Site work along Butler Pike would add a curb cut, a driveway and parking that start as gravel subbase for later paving, drainage, lighting, a meadow trail and accessible walkways. The tree line covers removal of invasive trees and reforestation. The Hovenden House second floor would become a caretaker's apartment, with remediation for moisture and radon, kitchen and bathroom work, window repair or replacement and a code-compliant egress system.

The second phase covers the rest of the rehabilitation. It adds a 300-square-foot accessible entry to the meadow side of the Maulsby Barn and a 1,000-square-foot courtyard addition with an elevator between the barn and Abolition Hall, and it rebuilds the hall's north balcony as a second means of egress. The report puts the second phase at about 8,000 square feet.

What the code review found

All three buildings are classed R-3 today, and the plans need a change of use

All three buildings are classed today as R-3, a residential occupancy. The report expects the township's plans to need a change of use, which under the International Existing Building Code that Pennsylvania's Uniform Construction Code adopts brings stricter requirements than an alteration within the same use. The proposed classifications are B and R-3 for the house and barn, and A-3, an assembly group, and B for the hall.

Preliminary code data for the three Corson Tract buildings, from the assessment report. Areas are approximate.

The report describes all three as Type III-B construction, with masonry bearing walls and wood interior framing. None has sprinklers or a fire alarm. It expects any major renovation to replace HVAC, electrical and plumbing in full and to add sprinklers, monitored alarms, exit signs and emergency lighting, concealed without harm to historic fabric. Most occupancies would need two separated means of egress from each floor.

The report lists what earlier surveys and the 2025-2026 site visits found.

Review and funding

The largest grant application, $250,000 for parking and trails, was pending in June

The tract sits in the Plymouth Meeting Historic District, so exterior work visible from a public way goes before the joint Historical Architectural Review Board of Plymouth and Whitemarsh, which uses the Secretary of the Interior's Standards for Rehabilitation. The report recommends consulting the board early. It says the property, in the VC-2 Village Commercial district, is understood to be exempt from the zoning ordinance because the township owns and operates it.

At the committee's June 25 meeting, the township manager reported on three grant applications. The minutes say the Greenways, Trails and Recreation grant would pay for parking and trails across the site and requires a 20% match, stated as $65,000, from the Open Space Fund.

What this means for contractors

Every priced line is above the $25,000 prevailing wage threshold

The report says near-term work needing specialized skills would go out through targeted requests for proposals to qualified specialty trade and restoration contractors, and that the larger rehabilitation would come in phased projects. The first-phase scopes call for masonry, exterior carpentry, chimney, window, site and environmental remediation work. Watch the Abolition Hall Steering Committee and Board of Supervisors agendas in the township's Agenda Center, and see the public bids guide for where township bids are advertised.

The Department of Labor and Industry says prevailing wage applies to building construction projects of $25,000 or more when public funds are involved, and a project may not be split into pieces to fall below that line. Every priced line in the report exceeds that amount. The prevailing wage guide covers rate requests and certified payroll.

Before pricing an exterior scope, ask the township whether the review board has issued a certificate of appropriateness for it.

Caveats

The ranges are early budgeting figures, set before design

The ranges are early budgeting figures. The report says professional construction cost consulting was not part of the study and that cost estimating will be needed as projects are defined. The second-phase dates and escalation are listed as to be determined. The $5.7 million to $7.1 million combined range adds the two phase totals and leaves out start-up work and the interim caretaker's quarters, which the report lists as township budget with no amount. Whether the committee or the Board of Supervisors acted on the invasive removal bid or the grant request could not be verified, because the October 27 meeting had not taken place when this was checked on October 26, 2026.

The data

Seven priced lines, from $50,000 to $3,100,000

Work, target schedule and estimated cost range for each priced phase of the Corson Tract rehabilitation, in dollars. Bars share one scale.

Source: Corson Tract Assessment and Preliminary Planning Report, June 17, 2026, Whitemarsh Township, checked October 26, 2026. Download the data (CSV)