What a conversion involves
A factory conversion keeps the shell of an industrial building, whether mill, warehouse, workshop or plant, and changes what goes on inside. The result might be apartments, live-work units, artist studios, offices, shops or a combination. People are drawn to these buildings for their scale and character: exposed brick, timber or steel structure, tall windows, large rooms and a sense of history. They are also drawn by the possibility of lower cost and a quicker route to new space than building from scratch. The reality is more complicated, because buildings designed for machines and storage do not easily become places for people.
This article focuses on the conversion work itself. The broader question of which historic features to retain, including adaptive reuse as a general approach, is covered in the discussion of industrial heritage, and creative commercial uses are discussed under industrial building reuse.
Reading the structure
Before design starts, engineers assess the building’s frame and envelope. Issues often include:
- Load capacity. Heavy industrial floors may handle apartments easily, but older timber floors might have lost strength through rot, vibration or past damage. Capacity cannot be assumed; records may be missing, and testing may be needed.
- Fire resistance. Old mill buildings sometimes used heavy timber that chars slowly in fire, which can be an advantage, but many other buildings use unprotected steel or combustible materials that need upgrading.
- Settlement and cracks. Movement in foundations and walls must be diagnosed and repaired.
- Masonry condition. Pointing, spalled brick and failing lintels need repair. Cleaning techniques that are too harsh can damage historic brick.
- Roof and drainage. Leaks are the main enemy of old buildings, and a good roof is usually the first investment.
- Hazardous materials. Asbestos, lead paint and residues need professional removal, often before design can be finalized.
Layout challenges
Industrial buildings have wide floor plates, regular column grids and few interior walls. These features create opportunity and difficulty.
Deep plans. In a building 60 or 80 feet across, the center can be far from any window. Designers might cut light wells or atriums into the floors, place corridors or storage in the dark core, or use shallow apartments arranged around the perimeter.
Columns. Columns and beams limit how rooms can be arranged. Good conversions treat them as features and design layouts to fit the grid.
Floor-to-floor heights. Tall ceilings are appealing, but they allow mezzanines in some projects and complicate heating. In shorter buildings, ceiling space for ducts and pipes may be tight.
Windows. Large windows give light but may be single-glazed and drafty. Replacing them can be costly and may be restricted for buildings with heritage designation. Solutions can include secondary glazing or approved replacement windows.
Circulation. Old buildings often have limited stairs and elevators. Adding them means cutting through floors and walls and fitting them into the structure.
Unit mix. A big floor can be divided into many small apartments, requiring corridors and plumbing risers, or a few large lofts. The market decides which works.
Code challenges
Converting a building from industrial to residential or office use generally counts as a change of occupancy, which brings the building under different rules than it was built for. Issues commonly include:
- Fire safety. Sprinklers, alarms, fire-rated walls and floors, and exits that satisfy modern standards. Wide exits and added stairs can be hard to fit.
- Accessibility. Step-free entrances, elevators, accessible bathrooms and routes. Meeting these in historic buildings may involve negotiation with authorities.
- Energy performance. Insulating masonry and old windows without causing moisture problems requires specialist judgment.
- Acoustics. Sound between apartments requires attention, particularly in buildings with open floors.
- Ventilation and daylight. Residential rules often require natural light and air to habitable rooms, which can conflict with deep floor plates.
- Utilities. New plumbing, wiring and mechanical systems need routes through solid structures.
Some jurisdictions have special codes or flexibility for existing buildings, allowing alternative ways of meeting safety goals. Early meetings with building officials can save time. Zoning can also require approvals, as industrial districts often prohibit residential use, tying conversions to the slow permit approvals that affect many projects.
Cost and risk
Conversion can be less expensive than demolition and new construction, but hidden conditions often lead to overruns. Reasonable contingency budgets are standard practice. Rehabilitation incentives sometimes apply to older buildings, with conditions on how work is done. Financing can be difficult because lenders may view unusual projects as riskier.
Neighbors and living conditions
Living in a converted factory can be wonderful for some residents and frustrating for others, with issues such as noise from neighboring industry, truck traffic, and the lack of nearby services in formerly industrial areas. Neighborhood effects matter too: successful conversions can raise nearby rents and change the character of the area. Existing small businesses and residents may feel the pressure. Planning measures such as affordable unit requirements and protections for existing tenants can offset some effects, although they have costs.
Realistic expectations
Conversion is best seen as a craft of working with an existing building, not forcing a design onto it. Projects that begin with a thorough survey, choose uses that suit the building, design around its structure and engage officials early tend to avoid the worst surprises. Even then, schedules and budgets are uncertain, and not every old building is worth converting. Where a structure is too damaged or poorly suited, honest assessment may point toward partial reuse or careful demolition.