Hampden Branch Library Renovation

Erected in 1899, the Hampden Branch of the Enoch Pratt Free Library in Baltimore, Maryland underwent modern renovations both inside and out, while preserving its historic appeal and doubling its footprint within the constraints of the property. The multi-million dollar extensive overhaul included digging out the basement to create a new meeting room, landscape upgrades, the addition of new public bathrooms, and a new handicap accessible ramp.

McLaren Engineering Group provided various innovative solutions for the library renovation. Preliminary design and planning services included a full site survey, preliminary site plan, and coordination with the City for permit exemptions. Final engineering services included the preparation of Final Site Development Plans and Final Landscape Plans.

The McLaren Difference: Applied Ingenuity

McLaren faced several challenges during renovation, including historic preservation restraints. Given the historic nature of the library, it was subject to additional reviews from the City of Baltimore’s Commission for Historical and Architectural Preservation (CHAP).

Civil Design + Stormwater Management

Civil design included re-grading the yard to accommodate the architectural site plan, adding ADA access ramps to both the upper and lower levels of the building, and stormwater management design retrofit.

The stormwater management design presented unique difficulties due to Baltimore City requirements for historic properties and lot size constraints. City requirements state all drainage must be maintained on site; however, due to historic preservation requirements, the building (roof drains included) had to remain unchanged. Through a series of subsurface drywell facilities and infiltration trenches, McLaren was able to reduce the post-development discharge to below pre-development levels, while reclaiming surface area for additional landscaping and recreation area. The stormwater management design provided for additional landscaping and achieved reduced overland flow to adjacent properties by mimicking natural drainage patterns and utilizing Environmental Site Design (ESD) techniques. For the underground stormwater management system, McLaren used micro-scale practices and ESD techniques to treat for water quality, and quantity control.

Additionally, by limiting all necessary improvements to the sides and rear of the building, McLaren’s team was able to preserve the building’s historical architectural frontage.

Landscape Design Library Renovation

The site’s existing open space was limited with roads to the front and rear as well as existing structures on both sides. However, McLaren’s design solutions allowed all proposed improvements to be completed within these constraints.

Landscape design included sculpting both side yards, front yard, and the rear yard. Bike storage was included in the design, as well as fencing with gates for security and an increased plant perimeter. The team also helped with utility connections for the new upgraded bathrooms and with coordination for the city permit exemptions.

Structural Engineering

McLaren provided structural engineering support of excavation (SOE) design for digging out the basement to create a new meeting room and sunken level entry. Retaining walls were repaired and designed along the side and rear of the property.


To assist this design work, topographic survey and property boundary survey were performed and utility location/elevations were collected.