When building in Boise’s Historic Districts avoid costly mistakes by securing a Certificate of Appropriateness and knowing the residential building guidelines. Boise has nine neighborhoods which have been classified as “Historic Districts.” These districts can be found in the interactive map here.

As the City of Boise’s website explains, for most homeowners, living in an historic district has little impact on the use and improvement of their property. But under State and municipal law, property owners must secure a Certificate of Appropriateness for external alterations to houses and structures.

A Certificate of Appropriateness is not required for items such as internal alterations, general maintenance, painting any portion of a building that has been previously painted, installation of sprinklers, or decks and landscaping that are not visible from the street. However, a Certificate of Appropriateness is required for major alterations. This helpful decision matrix explains what the City considers major or minor alterations.

If the proposed change is a major alteration, then the homeowner must ensure that they and their general contractor both understand the Design Guidelines for Residential Historic Districts.

These guidelines explain how the City’s planning department and the Historic Preservation Commission determine if proposed structural changes should be accepted or rejected.

Listed below are some common mistakes which occur when building in the Historic Districts. A complete list of these guidelines can be found here.

Building Materials:

Policy: Use similar building materials as those found within the district. Prevalent styles found within the districts use a variety of common building materials. Clapboard or shiplap wood siding (two to six inches wide), brick, stucco and sandstone are dominant ex-terior materials. Sandstone blocks are generally relied upon for foundations. Stucco, rusticated concrete block, and stone were sometimes used solely as wall material or for ornamentations.

Generally Appropriate:

  • Use exterior wall materials that are commonly present in the district
  • Ensure that the predominate texture of the new building is consistent with the texture of historic materials in the district.
  • Use wood or painted, composite wood-resin, or fiber cement sidings as building material in new construction

Generally Not Appropriate:

  • Use faux wood graining in composite or artificial materiasl used to simulate woods siding.
  • Use prefacbricated or metal buildings.
  • Use vinyl and aluminum materials on new buildings.

Windows, Doors and Facade Treatment

Policy: Maintain similar solid-to-void ratios of a new building to those of buildings on adjacent sites within the block with overall proportions of windows, doors, and front facades.The front facades of buildings within the district vary in style and detail. However, certain proportional relationships exist among buildings in the immediate setting. The importance of the relationship between the width and height of the front elevation of buildings on the block has already been discussed. Beyond that, the pro-portion of openings on the street-side facade, or more specifically, the relationship of width to height of windows and doors and their placement along the facade, should reflect the same relationships along the street.

Generally Appropriate:

  • Use double or single-hung sash windows.
  • Use a ratio of wall to window or solid to void that is similar to other historic buildings within the block or district.
  • Use wood or aluminum clad materials.

Generally Not Appropriate:

  • Use in-congruous window and door types
  • Use vinyl windows
  • Use aluminum doors with mill, brush or polished finish.

Roof Forms & Material

Policy: Use similar roof forms, slope ratios, and materials drawn from historic structures in the district.Roofs are major features of most historic buildings and when repeated along a street contribute toward a visual continuity. The architectural character of older buildings is generally ex-pressed in roof forms and materials. Typical roofs in Boise’s districts are simple in form with gabled, hipped, or occasionally a combination of the two. Roofs purposely extend beyond the building walls to protect the window and door openings and provide shade. These eaves are sometimes enclosed with wood soffits (the underside of a roof overhang) which are vented.

Generally Appropriate:

  • Use gable and hipped roofs as primary roof forms
  • Maintain congruity
  • Minimize the visual impacts of skylights and other rooftop devices visible to the public; these should be located toward the rear of a house.

Generally Not Appropriate:

  • Use a roof of a size, shape, color, or slope not typically seen in the district
  • Use corrugated roof material
  • Use “non-tradiational” building and roof forms that detract from the visual continuity of the streetscape.

These are just three examples of what the guidelines consider appropriate and inappropriate. When building in historic districts, please remember the City takes these guidelines seriously. Failure to comply with them could result in a denial of a certificate of appropriateness. Its best to avoid costly mistakes and know your neighborhood before you build.