Can This Building Become Apartments? What We Check Before You Buy

The conditions that determine whether a building is a good candidate for apartment conversion often aren’t visible from the outside.

Yes, many existing buildings can be converted into apartments. Whether they should be is a different question. The answer depends on the building's floor plate, structure, infrastructure, envelope, parking, zoning, and code requirements, and ultimately on whether the building can produce enough usable residential space to support the cost of converting it.

Some buildings convert into apartments beautifully. Others will quietly drain a development budget for years. The frustrating part is that the two can look nearly identical on a walkthrough, and the differences that matter most are often the ones a purchase decision will not wait for. We evaluate adaptive reuse and conversion opportunities throughout Ohio and the Midwest, including work in Columbus, Dayton, Cleveland, and Detroit. Before you buy a building hoping to make it housing, here is what we would want to know about it.

What makes a building a good candidate for apartment conversion?

Existing windows, building depth, structure, and envelope conditions all factor into whether an existing building can support an efficient residential conversion.

The best conversion candidates tend to share a shape: a relatively narrow rectangular floor plate. That geometry allows units to line both sides of a central corridor with daylight reaching every apartment, keeping layouts efficient and the percentage of leasable area high. A building can have great bones, a great location, and a great story, but if the floor plate forces deep, dark units or consumes too much square footage in corridors and common areas, the numbers can struggle from day one.

Beyond the shape, we are looking for a sound structure, windows that can serve dwelling units, an existing elevator, usable building systems, and parking, whether surface or garage. None of those guarantees a project works. Their absence, though, starts the meter running immediately.

What kills an apartment conversion?

In our experience, conversions tend to die from a relatively short list of causes, and most of them are difficult to see from the sidewalk.

Existing infrastructure is one of the first places we look. Water, electric, gas, HVAC, fire suppression, storm, and sanitary systems all need to be evaluated for their condition and their ability to support residential use. If substantial replacement or upgrades are required, costs climb quickly, and they are difficult costs to recover in the development analysis. The building does not rent for more because you replaced its water service.

Vertical circulation is another. If there is no elevator, adding one can be a difficult and expensive retrofit. Existing stairs need a hard look too, because their location, condition, width, and enclosure all carry code implications, and correcting them adds up quickly.

Then there is the structure. Some reinforcement may be manageable. A structural system that has deteriorated to the point that substantial portions need replacement is another matter entirely, because at some point you are no longer benefiting financially from having an existing building.

The building envelope can be just as consequential, especially the glass. A building wrapped in storefront or curtain wall that has reached the end of its useful life can add cost at a pace that surprises everyone at the table.

And finally, parking. If the site has adequate parking, that can be a major advantage. If it does not, creating it may introduce additional site, zoning, and stormwater challenges and can become a limiting issue all by itself.

Apartment Conversion Feasibility Checklist

Before we recommend moving forward with an apartment conversion, these are some of the major questions we want answered.

What We Evaluate	Why It Matters
01Floor Plate + Building Depth	Determines whether efficient units with adequate daylight can be created.
02Preliminary Unit Yield	Shows how much of the building can actually become revenue-producing residential space.
03Structure	Identifies deterioration, reinforcement needs, or potentially significant replacement costs.
04Windows + Daylight	Affects unit planning, livability, and potential envelope modifications.
05Elevators	Adding new vertical circulation can be a major cost.
06Stairs + Egress	Existing stairs may not satisfy the requirements of the new occupancy.
07Mechanical, Electrical + Plumbing Systems	Existing systems may be inadequate for residential use or near the end of their useful lives.
08Fire Protection	A change in occupancy may require significant upgrades.
09Building Envelope	Aging roofs, curtain wall, storefront, masonry, or other exterior systems can materially affect the budget.
10Accessibility	Existing conditions can create significant design and construction implications.
11Parking + Site Conditions	Can limit unit count and trigger additional site or stormwater work.
12Zoning	Determines whether the proposed residential use and density are permitted.
13Existing Drawings + Documentation	Good information makes early analysis faster and more reliable.

No single item determines whether a conversion works. The question is what they look like together.

Why are school buildings so hard to convert to apartments?

Former school buildings can have incredible character, but their original layouts don’t always translate efficiently to residential use.

We get asked about former schools often, and our advice is consistent: look deeper before you commit. Schools, particularly large ones, tend to have inefficient floor plates and wide corridors, and that combination works against residential conversion twice. The corridors consume square footage that will never generate rent, while classroom depths and building geometry resist becoming well-proportioned units. The leasable-to-common-area math starts out challenging and rarely improves. That does not mean old schools are hopeless. It means apartments are often the wrong second life for them.

We have evaluated school conversions where a building could technically accommodate apartments, but the early analysis showed that the revenue required to support the project would be extremely difficult to achieve. On one such project, the development moved forward despite those concerns, and from what we understand, it continues to face the same operating costs, revenue challenges, and infrastructure issues the analysis flagged. That experience reinforced something we see repeatedly:

Physical possibility and development feasibility are not the same thing.

A building may be capable of becoming apartments without being capable of becoming apartments that perform financially. Some of our favorite adaptive reuse projects are former schools that found an entirely different second life. The building often tells you what it wants to become. The trouble starts when a pro forma tells it otherwise.

Buildings do not become easier because we are optimistic about them.

What code and zoning issues should you expect?

Converting a building from another use to apartments typically involves a change in occupancy to Residential Group R-2 under the Ohio Building Code. That change can trigger requirements the existing building was never designed to meet. In our experience, mechanical systems are often one of the first places those requirements begin to affect a project, but we are also looking closely at egress, accessibility, fire protection, structure, and the other systems that come with residential occupancy.

Zoning is another early question, and it is not always as simple as checking a district name on a map. Columbus is a good example: the City is in the midst of Zone In, a multi-phase modernization of its zoning code, and new districts and standards have been introduced as part of that process. For us, the question is practical: does the zoning allow the residential use and density the project needs, and if not, what approvals will be required to get there? If a rezoning, variance, or other discretionary approval is necessary, additional stakeholders enter the process, and with them come schedule risk, uncertainty, and costs that need to be understood before acquisition, not after.

Is converting a building cheaper than building new?

Not always, and this is one of the assumptions we most often have to correct. Adaptive reuse gets described as the cost-saving path to apartments, and sometimes it is. Reusing an existing structure can preserve valuable materials, shorten portions of the construction process, and give a development a character that would be difficult to recreate. But between infrastructure replacement, structural work, envelope repairs, new vertical circulation, and code compliance, a conversion can ultimately cost more than building new. The existing building is only a head start if enough of it is actually usable, and whether it is, is a question of evidence, not instinct.

When should you evaluate a building for apartment conversion?

Ideally, before you own it. The best time to evaluate a potential conversion is during the acquisition and due diligence period, while there is still an opportunity to understand the building's risks before they become the owner's risks. That does not mean every question needs answering before closing. It means the questions capable of fundamentally changing the development plan need to surface early enough to influence the decision.

Finding out that a building needs a new mechanical system is useful information before you buy it. Finding out six months later is just an expense.

What is an apartment conversion feasibility assessment?

An apartment conversion feasibility assessment is an early evaluation of whether an existing building can support a viable residential conversion. We look at the building through both an architectural and a development lens: its geometry, potential unit yield, structure, systems, envelope, vertical circulation, accessibility, parking, zoning, and code implications, bringing trusted engineering partners into the process when needed so the building's systems get real scrutiny, not a glance.

The goal is not simply to answer “can we draw apartments inside this building?” It is to answer the more important question: can this building become apartments in a way that makes sense as a development?

How long does a conversion assessment take?

Usually less time than owners expect. Once we can walk the property, we can typically assess a building within about two weeks, working from existing plans when they are available or developing basic plans from field measurements when they are not. What you get is a thorough report with clear conclusions: either the findings support moving forward, or they identify the considerations and challenges worth confronting before you proceed.

Two weeks of looking is the cheapest thing that will ever happen to this project. Buying the wrong building is the most expensive.

Considering an office, school, warehouse, or other existing building for apartments? A conversion assessment can help you understand the building's potential and its expensive problems before you own them.

Talk to us before you close.

By Daniel Mayer, Principal. Dan leads design and technical work at DAC and has evaluated adaptive reuse and conversion opportunities throughout Ohio and the Midwest.