An apartment combination is the stuff of lore for many New Yorkers, but if you're one of the lucky few for whom that opportunity may present itself, there are many things to consider before making the offer on your neighbor's apartment. Theoretically, combining two adjacent co-op or condo apartments requires nothing more than removing a kitchen and creating a doorway-sized opening in a wall to join the two units. However, creating an new apartment that actually feels like a home in terms of flow, functionality and durability will require a much more extensive renovation.
Before you take the plunge, it’s important to consider the costs associated with combinations, both to make sure your budget can foot the bill, but also to make sure the value of the apartment you plan to create will be worth more than the sum of its parts in a resale.
Start with your building
Confirm your building will allow a combination, and find out as much as you can about what the process will entail. Depending on your particular circumstances, it may be desirable to purchase hallway or other common space from the building.
It is also important to understand the building's rules for this type of renovation, which is usually contained in the alteration plan. Your building's fees for renovation, use of elevators, protection of hallways, and potential penalties for exceeding the scheduled timeline will all factor into your budget. Costs will also vary based on what your building will require of your renovation, for example if you must update all electrical during a renovation or when the building requires you engaged a structural engineer.
Understand the costs with a team of experienced professionals
While the costs of a renovation can range from $200-$500 a square foot, this does not begin to address the question of what is a reasonable budget for a particular combination. Vertical combinations are more expensive than adjacent, but the condition of the respective units and the final vision you have for the combination (custom features are a major driver of cost) will make a huge difference.
Apartment combinations almost always require an architect. Many architects will charge a percentage to provide full-scale service from design and drawings to construction management, but if you are on a budget, it may be possible to reach another arrangement such as hourly or a flat fee. It is most important to be upfront about your expectations on scope of work and budget when speaking to architects.
Similarly, it is important to get quotes from several contractors to get a sense of what it will cost to get the work done. At a preliminary phase, it is difficult for contractors to estimate costs without drawings or a sense of the level of finishes desired for the combination. A trusted architect may be able to help you formulate a plan and anticipate other professionals you may need to hire (an expeditor to submit plans and navigate the permitting process, asbestos abatement, structural engineering certifications, or major electrical or plumbing upgrades).
The importance of a thoughtful layout
While there are legal requirements for light and ventilation when creating or moving kitchens, bathrooms and bedrooms, other factors are important to consider when creating your new floorplan. All too often, combination apartments have odd room sizes, weird areas of “dead” or unusable space, or just seem to flow weirdly. An experienced architect or designer will be able to offer you advice on how best to configure your new space, and create a floorplan that will maximize both functionality and value of your home. Keep in mind that not every combination may result in a desirable larger home that feels like it was meant to be a single space.
Moving major systems: kitchens and bathrooms
Other than in a few specific situations, New York City only permits one kitchen per apartment. A kitchen demolition can run anywhere from $5,000 to $8,000, but it’s important to consider whether your demo requires moving plumbing or waste risers. Plumbing risers are the most expensive thing to move around. Even if one apartment has a bathroom that lines up with the other apartment’s kitchen, you won’t necessarily be able to blast through the wall to create a giant kitchen or bathroom. The risers—which begin in the basement and end at the top floor—likely serve an entire line of apartments, so buildings usually forbid moving them for safety reasons, and to avoid major disruption to other building residents. If you are allowed to shift a riser line, keep in mind that it will likely add a at least $10-20K to the cost of your renovation.
The devil is in the details
Combining apartments that are mismatched in quality (e.g. if one is in estate condition) poses additional design challenges. However, even if you’re combining two renovated apartments, blending finish work between the two will almost always require updating trim, moldings, doors and windows. Surprisingly, this finish work may be one of your largest expenses, as it will typically involve custom millwork, framing, and built-ins. High-end custom millwork, such as full height bookcases, storage cabinets or elaborate wall panels, can run you anywhere from $200 per linear foot to $800 per linear foot.
Look at the big picture
While much of our focus here has been on the costs, ultimately the goal is to create value. Speak to an experienced real estate agent to get a sense of a realistic offer on the neighboring apartment and what the resulting combination may be worth. Their guidance may even shape your renovation plans including decisions on number of bedrooms/baths that would be most desirable as well as what level of finishes are likely to be appropriate at a certain price point.