Most New Yorkers hunting for an apartment to renovate put square footage at the top of their wish lists. Kurt Arnold and Aya Maceda prioritized something else.

“Before how big it was, or anything else, our focus was that we wanted an apartment with a good quality of light,” said Ms. Maceda, 42, a founder of the architecture firm ALAO.

The couple, who were searching for a home to buy in Cobble Hill, Brooklyn, in 2015, held fast to their desire for natural night, despite a number of competing demands: Their son, Kosi, now 10, needed more space, and they planned to expand their family further (they soon added a daughter, Lulu, now 4). They needed still more room for occasional overnight guests.

So when they found a listing for a compact duplex apartment with big south-facing windows, they thought it had potential, although it was a mere 660 square feet, with an open sleeping loft and no separate bedrooms.

“All Kurt and I saw were the large windows when we walked in,” Ms. Maceda said. “We were in the canopy of the trees. Really beautiful afternoon light was coming in, and there were shadows from the branches on the walls.”

Her husband hesitated for a moment. “He nervously asked me, ‘Can you make it work?’” Ms. Maceda said. “I said, ‘We can make anything work.’”

They bought the apartment that September for $712,000 and moved in without changing much, as Ms. Maceda began working on plans for a renovation that would make the most of every square inch.

Not only did everyone need a place to sleep, but the couple knew they would have to contend with a deluge of toys, art supplies and professional gear. Mr. Arnold, 42, is a photographer, and had a closet full of equipment, and he and Ms. Maceda planned to work from home sometimes.

“The design of the home had to address the energy of a creative household, while balancing that with our desire to have a simple, peaceful home,” Ms. Maceda said.

She was born in the Philippines and Mr. Arnold is from Grenada, and they wanted the apartment to have a tropical, modern feeling. “There’s a Filipino word, maaliwalas,” she said, that guided their thinking about the project. “It describes a generous space — open, bright — with a good flow of light and air.”

Unwilling to rent a second home to live in while the apartment was being renovated, they planned a phased approach to transforming their home, aiming to have the messiest work completed while they were away on family trips.

The first phase, in 2016, focused on the lower floor, where they added a two-level nook with a bed on the bottom and a play area on top, along with a built-in ladder, just inside the front door. “I was pregnant, and my mom needed a place to sleep, because she was going to help us in the first months,” Ms. Maceda said.

At the same time, they built a bank of closets to house Mr. Arnold’s photography equipment and various other things; renovated the kitchen and a small powder room; and tucked a desk with two workstations under the stairs.

During the second big phase, completed in 2018, they overhauled the upper floor, adding an 80-square-foot primary sleeping space over what had been part of the double-height living room (an interior window and a new skylight help it feel sunny, though it has no exterior window). They also transformed the old sleeping loft into a bedroom with bunk beds for their children and a play area with a curtain that can be drawn to close it off.

Of course, it’s not a renovation project if there aren’t delays. After a trip to Grenada during Phase 2, the family returned to find their apartment uninhabitable. Fortunately, “our neighbor was away,” Ms. Maceda said, “so we stayed across the hall.”

The last phase, which was completed in December 2019 while they were in the Philippines, included renovating the full bathroom and walk-in closet on the second floor.

Completing the updates in phases allowed them to spread the cost — slightly less than $100,000 in total — over a few years, Ms. Maceda said.

Since the pandemic struck in March, their reconfigured apartment has been put to the test. “From a working-from-home perspective, and with home-schooling, we have all the right tools,” Mr. Arnold said, including enough quiet corners for everyone to find some private space.

It helped that they filled the space with plants, including a 10-foot-tall fiddle-leaf fig tree, a lemon tree and hanging philodendrons that remind them of the vines near a favorite waterfall in Grenada. And in the early days of the lockdown, they added a small hydroponic system at the foot of the stairs so they could grow kale, lettuce and tomatoes.

“Staying here in Brooklyn was a decision,” Ms. Maceda said, noting that they only briefly contemplated leaving the city. “We felt like, no, we have everything we need in this little place.”

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