Turning Houses into Businesses

We have been involved with several conversions of residences to businesses in the past year. These projects share similarities because houses are different than commercial buildings. The structural, life safety, Americans with Disabilities Act, site design and environmental quality requirements are different. In fact, the requirements are stiffer. There is a large number of houses no longer suitable as a residence. These buildings are good candidates to turn a house into a business. With a dearth of adequate commercial space, we expect to see continued need for design input.

This article focuses on the architectural challenges to turn a house into a business such as a law office. We do not address zoning issues, or issues specific to food preparation business.

At some point, however, an organization may begin to feel constrained by their house. Following are some common problems and their causes:

Sometimes a small amount of work will turn a house into a business.  For instance, Americans with Disabilities Act requirements can seem overwhelming, but the law limits responsibility to a fraction of an overall renovation project’s cost. Specifically, the ADA has a “20 percent rule”, which states no more than 20 percent of a project’s cost needs to be applied to the removal of architectural barriers. If an owner spends $30,000 on a renovation, only $6,000 needs to go towards ADA improvements. A short wheelchair ramp or a paved accessible parking space would probably suffice. While other accessibility improvements are possible, the standard of care is 20 percent.

For small houses of one or two stories, the fire and life safety requirements can also be tame. Smaller businesses that expect less than 50 occupants do not require fire alarm systems. An emergency light over the front door and one right outside the door takes care of emergency lighting requirements.

Are houses typically laid out to function well as businesses? The short and obvious answer is no. Many houses are not laid out well to function as houses! We often see organizations deciding to make do with a floor plan because it is difficult to tell what is an easy change and what is a hard change. Frequently this question is structural: is that wall load-bearing?

A common reason to avoid floor plan improvements is financial. Sometimes an organization simply does not have the resources to move walls around, regardless the magnitude of the benefit. In this case, the organization may be limited to painting the mauve walls and putting a coat rack by the front door.

At some point, however, an organization may begin to feel constrained by their house. Following are some common problems and their causes:

  • Uneven heating and cooling: Older residences often have only one heating or cooling zone. A heating or cooling zone is the area of a building controlled by a single sensor, like a thermostat. If the upstairs and downstairs of a house is on the same zone, or if the south side and the north side are on the same zone, parts of the house may be cold, while other parts are hot. The cost of improving a mechanical system may be significant: think $10,000 or more.  Replacing a mechanical system may run $30 to $40 per square foot of house area. The result, however, is almost certainly better thermal comfort and lower energy consumption.
  • Little or no ventilation air: Related to uneven heating and cooling, many houses do not have active ventilation systems. While operable windows are a great source of fresh air, they are not practical to use in the middle of winter. Many homes heat using forced hot air, but the air in the system is recirculating. In other words, the furnace is heating up air from the house, and returning it back to the house. Small offices do not need a lot of fresh air. The amount is on the order of 15 to 20 cubic feet per minute per person. This amount can be brought in with a small heat recovery unit.
  • Poor acoustical separation: This is one of the most common issues with houses. The rooms are not designed to be acoustically separate from one another. The culprits are usually thin walls and hollow doors. Walls can be made more acoustically opaque by adding layers of gypsum board. Doors can be replaced with solid core doors. A larger issue comes with whichever room is used as the conference room. If the house had an open plan, making a sound-proof conference room may require at least one new wall.
  • Poor storage:  Residences store clothes in closets. Offices store papers and files. Closets make poor file storage rooms. There is little one can do except live with the inconvenience until the time is right to undertake a renovation.
  • No sprinklers: In general, a one-story house converted into a business does not need sprinklers. There are times when a two-story house will need them. The specific reasons why a second floor may or may not trigger a sprinkler requirement are beyond the scope of this article. Suffice it to say sprinkler systems can be installed for around $5 to $10 per square foot of area. See our blog post on Maine Life Safety System sprinklers.
  • Poor layout: Some houses have rooms that are just not the right size or quantity. There might be very large master bedroom and two small bedrooms, but the organization needs four private offices of about the same size. Taking a crack at floor plan adjustments is the only way to take care of this.
  • Inadequate parking: Because Maine is so rural, there are a lot of places where parking ordinances do not exist. One may be tempted to forego parking unless required. However, keep in mind employees need to park, and so do clients or customers. You will need at least one parking space for each employee, and three parking spaces for every one thousand square feet of usable building area. In cities with ordinances, you will need what the ordinance says.

How much should one be spending on improvements? It does not make sense to buy a house and then spend more for improvements than it would cost to build a new building. Paying $100 per square foot for a building and then spending $100 per square foot in improvements is probably near the top of the range. Anything more than that and you might be better off buying a tear-down.

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Principal at Sealander Architects, Ellsworth Maine. Revit guru. Married with 3 children. Avid gardener. Lived in San Francisco for nine years. Master in Architecture from Columbia University Bachelor of arts in religious studies, Wesleyan University. Graduated Staples High School, Westport CT. Hope to spend some time in Hokkaido before all is said and done.