The latest news on New York architecture.

  • Challenges in Adaptive Reuse of Historic Buildings: The Armories of NYC

    Challenges in Adaptive Reuse of Historic Buildings: The Armories of NYC

    The world of adaptive reuse and historic preservation has found ways to successfully adapt and use historic buildings in modern neighborhoods. Social needs, such as for artist's housing, and needs for adaptive access, so all citizens can use the old buildings, have been successfully met. The old armories, however, have a number of challenges that are unique to their nature as urban fortresses.

    The armories were developed initially as the home fort for state militias, with room for storage of ammunition and weapons, room for drilling a company or more of soldiers, storage and living quarters, administrative offices, storage and management of provisions--all of the space needed to house, feed, and equip a fighting unit of soldiers. So the armories are huge, both large in interior space, many an entire block long, and built with the sturdiness of a building designed to protect armament. This massive scale, both in size and in the thickness and weight of the walls and other structural supports, is a challenge when adapting the spaces to other uses.

    The armories have mostly been in the ownership of the state, and as they were no longer needed for active military service, the state has ceded ownership over to the city. The city, having responsibility to provide some social services for their people, used the large spaces to provide homeless shelters and other social service needs. The grand scale of the buildings make them useful for a large-scale operation of this type, but neighborhoods have had difficulty when these needed but challenging uses impacted the quality of life in the neighborhood. In addition, there is some thought that the buildings, being designed as they were, should be prepped and available for citizens to use in the event of natural disasters. This potential use, while needed, is very expensive to maintain as space.

    Some armories are being studied to evaluate their feasibility to be adapted into mixed income housing. Like many of these projects, competing interests of neighborhood quality of life versus the need for affordable housing makes the conversation challenging.
    It will not be easy or cheap to adapt these massive military forts into uses for the modern day, with access for all and the systems that in modern life we need, such as HVAC, fire suppression systems, modern water catchment, sewage and plumbing. But their architecture is unique, and their scale and grandeur cannot be duplicated in modern times. To retain their uniqueness, we need to find suitable connections and interests between competing parties, and meet the challenge of adaptive reuse with innovative thinking.

    For more information on adaptive reuse and historic building preservation, please contact us.

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  • What is Underpinning?

    What is Underpinning?

    Underpinning is a process used to repair, strengthen, or increase the depth of an existing foundation by lowering the footing to allow it to rest on more supportive soil.

    While oftentimes underpinning is associated with the remediation of deficient or failing foundations, it is also used in cases where the use of a building has changed, floors are being added to upper stories, or additional depth is desired in subsurface spaces, such as basements or cellars. In dense urban locations, such as New York City, underpinning is also a common practice during the construction of adjoining, adjacent, or nearby structures that require the removal or excavation of the soil supporting the neighboring properties.

    The process of underpinning begins by removing or excavating the soil from beneath an existing foundation.

    To avoid the risk of undermining the foundation, which may lead to structural failure, the removal of the soil is performed controlled stages, called ‘pins’, of limited length. The depth of the excavation is determined by a geotechnical engineer, who assesses the soil composition to identify the strata that is suitable to bear the weight of the building. The excavated soil is replaced with new material, typically concrete, which forms a new foundation beneath the existing one. Once one of the ‘pins’ is complete, and the concrete is cured, the process is repeated on the next section of the foundation until the entire length of the wall is reinforced.

    There are multiple methods of underpinning including:

    • Mass Pour
    • Beam and Base
    • and Mini-Piled

    The mass pour method is the most common due to its low cost and ability to resist heavy foundation loads. In this method, a solid, continuous concrete foundation is poured beneath the existing foundation is sections. While this method uses a great deal of material, it is the simplest method to engineer, does not require heavy machinery, and can allow for continuity of use during construction.

    A more technically advanced method is the beam and base method, where a reinforced concrete beam is constructed below the entire foundation to replace the existing footing. In this method, the new beam transfers the load to a mass concrete base which spreads the load evenly across the soil. While more advanced in its design, the feasibility of this methods largely depends on the structural configuration of the building above the foundation.

    Where ground conditions are variable or access around the area of the foundation is limited, the mini-piled method of underpinning may be used. In this method, ‘piles’ or deep vertical structural elements are driven into the ground in drilled holes deep enough to allow the piles to rest on stable soil. The piles typically extend at least 15’ below ground, but depending on the soil condition, are capable to depths of over 50’. While this method can overcome even the most adverse soil conditions, the engineering is more involved, and the process can prove to be quite expensive due to the technical expertise and specialty equipment required.

    If you are planning on performing structural work on your existing property – either elective or as part of a remediation program – it is important to hire a firm with extensive experience working closely with structural engineers, geotechnical engineers, and the NYC Department of Buildings to mitigate the risk of negatively impacting your property and those adjacent to you.

    If you have any questions about performing work on your existing building, do not hesitate to contact us.

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