AD-APT: Into the Deep.

Unlocking the deep floorplate is complex, but not impossible.

Today’s cities face two unignorable truths: the first is that our spatial needs are evolving more rapidly than our urban fabric, and the second is that our world is experiencing a climate crisis.

At the same time, the urban vacancy rates for commercial buildings are high. Office attendance has stabilized at 30 percent below pre-pandemic level and retail foot traffic stands at 10 to 20 percent below1[i] McKinsey Global Institute, Empty spaces and hybrid places, July 2023. – leaving a great deal of urban office, entertainment, and retail space empty.

The majority of these vacant buildings are Grade B commercial stock, placing them between 70 and 30 years old with floorplates between 10000 and 300000 square feet. Tired and in need of repair, there are some 257,772 examples of this grade of commercial building in New York and Los Angeles alone.

The process of weighing the question of what to do with these empty buildings against our need to respond to our expanding spatial needs more sustainably has yielded a common answer: Adaptive reuse. More specifically, that the oversupply of outdated commercial space and undersupply of housing can be easily balanced out by converting the former to the latter.

According to research by ERA-co, there are around 257,772 examples of Grade B commercial stock in New York and Los Angeles alone.

But dare we investigate further, we find the realities of physical, financial, and regulatory constraints lurking just beneath our feet. Code, laws, and economic evaluations – on top of the case-by-case constraints of our buildings and cities – make navigating the complexities of adaptive reuse can threaten its real-world implementation.

The opportunity in the depths.

While some adaptive reuse opportunities lend themselves to a smooth transition of purpose, the path for others is harder. Deep floorplates pose a challenge that requires a profoundly considered design solution. Dark, cavernous, and habitually less articulated than their smaller, often more historic counterparts, buildings with deep floorplates are dotted across our global cities – totally empty.

The path to the best, most sustainable future requires architects and designers to find ways to make the constraints of the deep floorplate into opportunities, meeting their challenges with strategies that work for the building’s end user, site, and city. Clearing a way to this path also requires revisions to outdated local building codes across the world that may be holding back a city’s ability to convert buildings.

Woods Bagot has complete a number of major adaptive reuse projects internationally, including AMANO, Campus Perth, 49 Chambers Street, Gramercy Square and Dahua 1935.

Demolition is not the default.

Adaptive reuse has the right priorities. Whatever problems may need to be pulled to the surface, the fact remains that another 2.5 billion people will be living in urban areas by the time we reach 20501United Nations, Department of Economic and Social Affairs, Population Division (2019). World Urbanization Prospects: The 2018 Revision (ST/ESA/SER.A/420). New York: United Nations., with the populations of North America and Europe set to peak before 21002North America and Europe reach a combined population of 1125 million. United Nations Department of Economic and Social Affairs Population Division, World Population Prospects 2022: Summary of Results, 2022. UN DESA/POP/2022/TR/NO. 3.. The immense pressure these numbers will place on our resources and infrastructure alone makes the ambition that drives adaptive reuse the most important of this century: to reduce the environmental impact of urban development.

It is unacceptable that the lifespan on many modern commercial structures today is closer to 20 years than 1003ARUP, Transform and Reuse: Low-carbon futures for existing buildings, Arup 2020. . Aspirational and ambitious, adaptive reuse promises a more mindful future by forcing us to consider how much change we’re really entitled to in a building, as well as its future uses. There’s an arrogance in demolition, and we need to leave blank slate thinking behind.

One way to think about adaptive reuse is to liken it to a career change. Though undoubtedly a challenge – psychiatrists rank the stress above that of taking on a mortgage – changing careers is often necessary in terms progression, relevance and earnings, all reasons a building might need to change, too. The average person will experience major career change three to seven times before they retire, and we need to normalize the building doing the same.

Sites of change: Deep floorplates in Los Angeles and New York.

According to research by ERA-Co, office buildings from the 1960s and 1990s account for a dominant 27.9 percent of B-grade commercial buildings in Los Angeles. Clustered along Wilshire Boulevard between Rodeo Station to MacArthur Park, there is a near-equal split of buildings with floorplate size between 13,000 and 20,000 square feet and those with larger plates between 30,000 to 100,000 square feet. Both sizes are considered too deep for traditional residential planning modules but can be reimagined with the right approach.

In New York, large commercial floorplates are grouped primarily within Midtown East and the Financial District. Spanning an excess of 30,000 square feet, these sites were also constructed after 1960 and – despite being increasingly less popular as offices – could be seen as the future residential development hubs of Manhattan, thanks to the neighborhood’s connection to public transit. Considering the city’s ‘moonshot’ goal of meeting the need for 500,000 residential units over the next decade , opportunities of this scale are of great importance to the city.

Los Angeles and New York are both sites of consistent development. Even to those who have not experienced them firsthand, the two largest and most famous cities in the US are characters known for their dynamic, ever-evolving natures – they are sites of consistent evolution. Now, our research shows that both are the perfect proving ground for the next wave of adaptive reuse, offering seeds of a solution to a global problem and continuing their long tradition of spearheading world-wide change.

Light can’t penetrate deep floor plates.

Unlocking the deep floorplate.

The common challenge for a complex office floorplate is solving how to break through darker depths. Where the 1940s and 1950s saw office buildings typically span 50 feet from core to glass, the 1960s through to 1990s saw the rise of bigger, deeper floorplates.

Unlike their more amicable predecessors, these deeper floorplates are considered harder to turn into apartments because they’re darker – but given their prevalence and vacancy, they’re the ones that need to change. One of the first things to consider with complex floorplates of this scale is what the right amount of change might be. Alongside a change of use, a complex floorplate might need to consider significant envelope modifications, changes to area, or the necessity for a mix of uses – all of which come with their own set of planning approvals.

Working with deep floorplates requires an approach that unlocks the building’s floorplate, cutting into the ‘grid’ in ways that consider future use. Dependent on variables like location and laws, we can approach this to add value in several ways:

The Perimeter is an approach to the deep floorplate that is common, but rarely the best.

The Perimeter.

This approach is what’s been most typical when larger floorplates are converted to residential. It involves placing units, normally around 30 feet deep, around the building’s edge to create a border of standard-size residences that have access to natural light in all habitable rooms via a minimum of one side (two for a corner apartment). The main issue with The Perimeter is that it leaves a large, central area of the building’s floorplate unused and without access to light and air, leaving a frustratingly dark space that lacks a purpose and, for the building owner, generates no potential for additional rental or sales income.

The Slim-fit.

Some jurisdictions will allow the retrofitting of leaner, longer units that extend into the depths of the darker floorplate. This creates space for more apartments and – by extension – more revenue potential. The approach solves The Perimeter’s problem of unused space and allows for more apartments to fit on a floorplate, but it does leave space in each apartment without direct access to light and air. While smart design and programming can go a long way towards solving this matter, it is important to note as a potential challenge to designing livable spaces.

The Slim-fit creates space for more apartments and – by extension – more revenue potential.

The Atrium creates an inner cavity that allows light to reach through the buildings’ core.

The Atrium.

The Atrium approach involves cutting the dark, harder to repurpose part of the existing structure out of the building center to create an atrium: an inner cavity that allows light to reach through the buildings’ core. To avoid a loss of building area, the removed zone can be repositioned as an ‘overbuild’ on top of the building. While this method is the most direct in solving the challenge of access to light, structural removal is costly and current regulations may not allow for the additional massing at the top of the building to recognize all floor area that’s been removed, an unappealing premise to underbuild in some of the world’s most expensive cities.

The Lightwell.

A similar approach to The Atrium, The Lightwell sees architects cut away a smaller cavity – a lightwell – through the building’s dark core to create light and air for interior-facing units. This approach allows natural light into all homes but does sacrifice some of the ample space on the original deep floorplate. However, The Lightwell does make room for additional, interior-facing units, which may appeal to investors.  

The Lightwell creates light and air for interior-facing units.

The Inset creates more outdoor space also allows for normalized unit depths.

The Inset.

Adding exterior loggias and pushing the facade of the building in at the large base of existing building to create more outdoor space will also allow for normalized unit depths. In this instance, exterior outdoor areas could be included in unit sales costs where an interior center area cannot. In most cases, office building facades will need to be reclad to allow for operable windows – so shifting the location may not be an increased cost.

The Storage Core.

The Storage Core approach is one that would allow the center of the building to be used as a secondary building typology – like third-party storage or a data center – allowing for minimum adjustment to existing floorplates as well as additional opportunity for revenue. To allow for each use type to function independently, additional core vertical transportation and egress will be required. This concept has now received attention from cities, such as New York in their new ‘City of Yes’ proposal.

The Storage Core approach is one that would allow the center of the building to be used as a secondary building typology.

Adapt for the best use.

Adaptive reuse supports a practice of ongoing care – for history, the built environment, the natural environment, and the future. While the deep floorplate comes with its own set of challenges, approaches like The Perimeter, Slim-fit, Atrium, Lightwell, Inset and Storage Core demonstrate how architects can reposition, reprogram, and redesign these underutilized spaces to better fit future needs.

When we consider the large number of deep commercial floorplates lying vacant in the two most populated cities in the US within the larger context of rising populations and vacancy rates globally, it’s clear that the best, most sustainable path forward for most is reuse.

A large part of a building’s embodied carbon footprint lies within the foundation, structure, and envelope. Therefore, any opportunity to salvage those elements within a repositioned building may help developers and investors with not only the costs typically associated with new buildings, but also with reducing the footprint of continued development within urban cores as they reshape themselves to meet today’s needs.

Ultimately, to embrace adaptive reuse is to adopt a different way of viewing the world – accepting that a second (or third, or fourth) life does not mean second best.