Renovating an existing building entails complex issues and factors (e.g., building condition, construction type, codes and zoning, location, swing space, budget, accessibility, sustainability, historic attributes).
Types of Renovation
Renovation scope can vary widely but implies more than a simple repair or routine maintenance. Types of renovation are defined differently by state building codes and include (per the Massachusetts building code) repair (reconstruction or renewal of any part of an existing building for its maintenance); alteration (construction or renovation to existing structure, other than repair or addition); and restoration (accurate reconstruction or repair of forms and details of a building or structure to a specific period; adaptive reuse, or change of use). Secretary of Interior standards for historic buildings (adopted by many local historic districts) categorize renovation as restoration (similar to Massachusetts), preservation (measures needed to sustain historic property existing form, integrity, and materials), rehabilitation (alterations, compatible use via repair, and additions while preserving historical, cultural, and architectural values) and reconstruction.
Renovation vs. New Construction
Many factors are weighed before deciding whether to renovate a building or demolish it in favor of new construction. An architect or engineer with experience in renovating older buildings objectively evaluates the building (e.g., historic or subjective value, budget, swing space). Sustainability can justify renovation over new construction; recent research indicates that even if 40 percent of the materials are recycled, a green energy- efficient new office building needs approximately 65 years to recover energy lost in demolishing an existing building (and most new buildings do not last that long).
The building evaluation is best performed by design professionals with relevant experience: for small projects, an architect or facilities personnel; for larger projects, a team led by an architect, ideally with experience working together. The facilities staff works with the evaluation team to plan scope and timing; supplies information on previous building work; offers access to drawings, specifications, work orders, and archival data; and helps arrange meetings with maintenance personnel and building users and access to rooms. The next step is an existing conditions survey, using current drawings or creating base drawings (e.g., with floor plans, floor-to-floor heights, elevation, section, detail information) as the basis for field notes, identification of problems and needed repairs, and construction documents. The existing conditions survey documents condition of finishes, structural systems, and building systems; includes an environmental survey (or an independent survey) to identify hazardous materials early in the process; evaluates the exterior envelope (e.g., roof, windows, wall construction), using thermographic imaging as needed; assesses life safety systems, accessibility, interior finish wear, and signs of deterioration; analyzes internal and external signs of structural instability (e.g., visual inspection, destructive or nondestructive methods); investigates potential structure loading capacity (e.g., floor loading, seismic requirements, code-required structural upgrades); evaluates electrical systems (e.g., equipment, lighting fixtures, wiring); assesses HVAC functioning and efficiency, including equipment and piping tests, sprinkler piping, and sprinkler head layout (whether compromised by previous work); and identifies information technology project systems, expected upgrades, and access and flexibility for wiring and maintenance.
Programming for Renovation Projects
If a renovation project includes new programmatic or building uses, a key issue is how best to adapt a building for desired changes. Each alteration (some easy, some difficult) has a direct effect on project budget. If a full existing conditions survey is not available, the architect can prepare a limited feasibility study or conceptual plans (with estimated costs, basic engineering systems) based on institution data on existing conditions to assess whether a building can be renovated to accommodate a proposed program. Existing buildings can have unique or historic features that offer an opportunity for innovative uses.
Building Code and Zoning Regulations
Routine maintenance and repairs usually do not trigger building code upgrades, but an existing building alteration or change of use almost always requires code- related upgrades unless variances are granted. A number of states have rehabilitation codes that treat renovations less stringently than new construction; often, only renovated building areas are subject to current standards. Some states offer code requirement exemptions to maintain the cultural heritage embodied in historic buildings. Changes of use often require standards of new construction, although some building codes base those requirements on whether the new use poses a greater, equal, or lesser hazard. Zoning ordinances also can affect renovation project scope and sometimes prohibit specific changes of use and physical changes.
Developing an Accurate Budget
An accurate budget depends on documentation of existing conditions and a thorough renovation scope of work, but some conditions are unknown until work begins. The school must budget for changes during construction, especially in renovation projects. A construction manager on the design team often provides budget information early in the process. The budget should include a contingency amount at each design process stage, including schematic design, design development, and construction documents. The amount can be 20 percent of cost at the schematic design stage; as construction documents evolve, the percentage is reduced. Sometimes the architect prepares cost estimates, but more often than not, the architect hires an independent cost estimator; on larger projects or where the budget is extremely tight, both a construction manager and an independent cost estimator can prepare independent estimates, with later reconciliation. Creating mock-up rooms supports development of an accurate budget.
Different building problems are typical in different construction types (e.g., brick or stone masonry bearing walls, wood frame construction, steel-framed or concrete-framed buildings).
Historic building renovation requires specialized design expertise by architects or engineers familiar with historic preservation technical issues and with structure rehabilitation methodology (e.g., historic building code requirements; preservation guidelines; materials conservation methods; specialized conservators, craftsmen, contractors, products.). Secretary of Interior standards provide renovation guidelines. A historic structure report is often the guiding document for renovation, with existing conditions data and a description of building history and unique character- defining features that make it historically significant. Design-sensitive interventions respect the original architecture while providing solutions.
When renovating existing buildings, institutions must be aware of ADA, state building code, and other accessibility requirements. The ADA Accessibility Guidelines are used with ADA; many state building code regulations are based on ANSI standards. Even in historic buildings, at a minimum, an accessible route to the building, accessible entrance, and accessible restroom facilities are usually necessary. Integrating accessibility into existing buildings is not always simple; this work often is accomplished as part of a larger renovation project, with modifications serving other programmatic needs simultaneously.
Sometimes an existing building does not have enough square footage to meet programmatic needs, which might require adding space or finding more space (e.g., by renovating an unfinished basement or attic).