Transatlantic Light: Integrating UK and NYC Legal Frameworks with CBDM

Introduction:

The integration of climate-based daylight modelling (CBDM) into the legal framework of a landmark development project in New York City marks a significant departure from conventional practices, particularly those observed in the United Kingdom. This paper explores the unconventional application of UK principles regarding daylight and rights to light aspects in the context of the Central Park Tower project, slated to become the world's tallest residential building upon completion in 2018. By employing CBDM, the study aimed to assess and mitigate potential daylight injury to neighbouring buildings, with a focus on the Art Students League of New York (ASL) building.

Background and Context:

Traditionally, the assessment of daylight injury in building projects involves evaluating the impact on surrounding spaces' daylight provision, often guided by local customs, legal requirements, or planning guidelines. In the UK, for instance, the "rights to light" schema is employed to determine potential infringements on existing spaces' daylight adequacy. However, applying such practices in the context of New York City presents unique challenges, particularly concerning zoning regulations and building height limitations.

In New York City, building bulk and height are primarily governed by the Zoning Resolution, which utilizes Floor Area Ratios (FAR) to regulate building size. Zoning Lot Mergers (ZLM) further allow developers to consolidate adjacent lots, enabling the construction of larger buildings beyond standard zoning limitations. The ASL building designated a New York City Landmark, faced potential daylight injury due to the proposal's significant height increase and design changes, including a cantilever (see Figure 2) over the ASL building's skylights.

Daylight Injury Evaluation:

The evaluation of daylight injury in the project occurred in two stages, in 2005 and 2013, utilising CBDM to predict daylight availability and potential impacts on the ASL studios' skylights. The study incorporated climate data to simulate hourly variations in sky and sun conditions, generating cumulative luminance maps for annual daylight assessments. The results revealed the potential reduction in daylight reaching the skylights under various scenarios, emphasising the need for careful design considerations to mitigate adverse effects.

Legal Agreement and Implications:

Remarkably, the legal agreement governing the proposed development incorporated measures of daylight availability based on CBDM, a departure from traditional practices. Negotiations between the ASL and Extell Development Corporation, the tower's developer, involved considerations of potential daylight injury and mitigation strategies. Notably, Extell retained the right to construct a building that might significantly impair light levels, subject to a one-time payment of $10,000,000 to the ASL for damages, underscoring the tangible risks and financial implications involved.

Broader Significance:

The Central Park Tower project's integration of CBDM into the legal agreement sets a precedent for addressing daylight injury in urban developments worldwide, including a very dense NYC area (my favourite!??). By embracing modernised approaches to daylight assessment and mitigation, cities can navigate the complexities of urban planning while preserving the quality of life for residents and neighbouring communities. This study not only highlights the evolving nature of daylight regulations but also underscores the importance of interdisciplinary collaboration and innovative methodologies in shaping sustainable urban environments for the future.

The outcome of the project was the approval of the revised design in late 2013, following extensive deliberations among key stakeholders. Despite concerns about potential daylight injury to the Art Students League of New York (ASL) building, the project proceeded with modifications aimed at mitigating adverse impacts on neighbouring properties. Through negotiations between the ASL and Extell Development Corporation, the developer of the Tower, measures were implemented to minimise the tower's impact on daylight reaching the ASL studios' skylights.

Martyn Duczek BSc MBA MSc RICS (APC)

Reference: https://hdl.handle.net/2134/19988