According to John Patrick Cunningham, building in New York is a lot like filing your taxes. “It's like, ‘What can you write off as an expense?’” says the Brooklyn architect. “There's a lot of gray area about what you can do and if people will give you a fuss about it.” Combing through complicated codes, sleuthing for loopholes, and maximizing your returns are par for the course. “It’s always a negotiation,” he adds. This approach was particularly relevant for a recent project of his, the conversion of a dilapidated backyard shed in Queens into a serene indoor/outdoor “living annex.”

Small garages that have fallen into disrepair stand behind many single-family homes in Queens because it’s challenging to renovate them. Many are no longer in compliance with setbacks, which presents a problem: they’re crumbling, but if you tear them down, you can’t build something new to replace them. Meanwhile, the driveways leading to them are too narrow to drive down. So many become storage sheds.

In 2024, New York City legalized the construction of ADUs across the five boroughs, allowing homeowners of single- and two-family homes to convert attics, cellars, basements, and free-standing or adjacent buildings into an ADU. While the law hadn’t yet passed when Cunningham began working with a family in Queens, they were aware of the potential policy change. They came to him in early 2024 with a 350-square-foot backyard shed with a caved-in roof and a $100,000 budget to renovate it. The Forest Hills residents sought a space that could flex between home office and a craft/playroom for their two children, and make their backyard more livable.

Editor’s Note: General contractor fees are included in costs.

$5,000 Interior Framing & Insulation	$10,000 Roof Framing & Insulation	$9,000 Structural Reinforcement of Existing CMU Wall
$6,000 CMU Storage Addition in Rear	$5,000 Exterior Siding and Soffits	$5,500 Wall Finishes
$6,500 Flooring	$4,000 Roofing - Architectural Asphalt Shingles	$4,000 Roofing- Gutters
$13,200 Electrical and Lighting	$6,000 Landscaping - Sod	$20,000 Landscaping - Paving
$15,500 Windows & Exterior Doors	$3,500 Interior Doors	$1,964 Permitting
$11,757.50 Architect/Design Fee	$11,000 Demolition & Waste / Debris Removal
Grand Total: $137,921.50

“Doing anything in New York for a hundred thousand bucks is such a challenge,” Cunningham says. Working with an expediter—a go-between that facilitates the permitting and approval process—was especially useful in exploring just how far he could push the design while remaining in compliance. The core strategy? Framing the design as a renovation, defined as retaining at least 50 percent of the original structure. This also helped them save money since they could reuse the foundation and concrete masonry walls. Cunningham designed a new roof so it has the same height and silhouette as the original structure, but with deeper eaves that provide protection from the elements. To fulfill the clients’ wishes for an indoor/outdoor space, Cunningham installed two sets of wide French doors from Gamco.

The interior is essentially one big room. It’s mostly finished in budget friendly materials, which also helped with the bottom line. Instead of building a new floor, Cunningham applied a layer of self-leveling concrete top coat for “massive savings,” he says, then surfaced it in Forbo’s Marmoleum Cocoa linoleum (a splurge) in Indigo Milk, a gray-blue with a warm speckled appearance. White-painted beadboard lines the pitched ceiling. Cunningham specified drop lighting fixtures from Volume Lighting, which are more cost effective than recessed lighting.

While the residents are using the renovated space as a bonus room for their own family, they designed it knowing they might convert it into an ADU in the future. Infrastructural details like an independent electricity supply, HVAC system, and more windows will ease the transition. When the time comes, the residents can just remove the closets lining the rear wall and install a kitchenette and bathroom on their former footprint.

“Even if somebody doesn’t convert a space like this to an ADU, this whole borough has all of these decrepit, weird buildings behind their houses and no one does anything with them,” Cunningham says. “Figuring out how to give this small space a new life was super exciting to us.”

Top photo by John Patrick Cunningham

More Budget Breakdown stories:

An L.A. Artist Gives His Home a Colorful Overhaul—and a New ADU—for $320K

To Fill an ADU With Light, $55K Yellow Window Frames Were a Design Necessity

Project Credits:

Architect of Record: John Patrick Cunningham / @jpc_architect

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Budget Breakdown: They Turned Their Sad Garage in Queens Into an Airy “Living Annex” for $100K