Altering Historic Structures

The Boulder County Community Planning & Permitting office at 2045 13th St., Boulder is open to the public on Monday, Wednesday, and Thursday from 8 a.m. to 3 p.m., and on Tuesday from 10 a.m. to 3 p.m. Appointments are available on Tuesday but are not required. Schedule an appointment.

Demolition and Alteration of Historic Structures

Deconstruction or building permits are required for all demolitions and alterations of historic buildings in Boulder County.

Permits for Alterations and Demolitions

If your building is 50 years of age or greater please contact the historic preservation staff as soon as possible to discuss whether or not more research or further historic review is warranted before a building permit is granted.

Please see Article 15-400 or 15-600 of the Boulder County Land Use Code for information on the reviews for non-designated or designated structures.

Historic Preservation Advisory Board (HPAB) Permit Review

The Historic Preservation Advisory Board (HPAB) is responsible for reviewing demolish and alteration requests to determine if:

  • The building to be altered would qualify for historic landmarking
  • The proposed alteration would be detrimental to the building

The Community Planning & Permitting staff will make an initial determination and if they believe that the structure has potential to be significant and has reasonable integrity they may schedule the permit with the HPAB.

What Happens If I Want To Demolish Or Alter A Structure That Is Eligible To Become An Historic Landmark?

If the HPAB feels that a structure is historically significant (qualifies for landmarking) and feels that the proposed action will destroy the significance, they may request that the Community Planning & Permitting Department delay issuing the permit for up to 180 days. This time period allows the property owner and the county staff to discuss alternatives to the destruction of an historic resource. If no solution for preserving the building(s) is reached within the 180 day period, the permit will be issued regardless of the historic preservation issues. However, if the applicant is going through another type of Land Use review (such as a site plan review, special review, etc), it could become a condition of that approval to retain the historic structure.

Helpful Hints for Historic Buildings

Renovation of an older house offers challenges and rewards. It’s natural for an owner to want modern convenience combined with the character of an historic home. Fortunately, with a little forethought, the two goals can be accomplished at the same time.

These hints focus on design issues that are commonly addressed by Boulder County’s Historic Preservation Advisory Board (HPAB). If you’d like more detailed information, please feel free to contact the historic preservation staff who can often answer your questions. If not, we’ll try to put you in contact with an HPAB member or other resource who can answer your questions or give advice.


Rural houses, whether farm houses or mountain cabins, were usually small compared to the houses in the 1990s. The most common change to historic buildings in Boulder County is to add more space. Unfortunately, additions to your historic building will look out of place if they overwhelm the original structure. Here are a few ideas to help with this design challenge:

Place the addition at the rear of the structure and try to use an intermediate building height to “step-up” from a one-story house to a two-story addition.
Attach a larger addition to the house through a breezeway or corridor.
Vary the roof shape using dormers or other techniques. The variety breaks up a larger expanse of roof and helps blend the old with the new.


Look at your house and determine if there is a reoccurring feature. If you notice that there is a window every four feet or there is a sunburst pattern in the woodwork over each doorway, these are the types of patterns that you would want to preserve on the original structure. Take the idea of the pattern one step further – if you are planning an addition, use the same patterns in the new portion of the house.


One of the most important features that define the time period of your house is the size and shape of the windows. If you’re trying to retain the charm of your house, keeping the windows is one of the easiest methods. The materials of the window frames are less important than the size and shape. However, wood frames work best. Staff can help direct you to sources who can repair existing windows and make them more energy efficient.

Roofing Materials

Historically, the most common roofing material in Boulder County was sawn wood shingles. Metal was also used, more frequently in the mountains. Today, we know that wood roofing materials conflict with the goals of mitigating fire hazards. If you are replacing a wood shake roof, you may want to consider a roofing product that has the same color as wood but is less flammable.


Similar to window size and shape, the orientation and size of the siding on your historic house is an important feature that helps define the period of time in which it was constructed. If your house has wood lap siding, it would be ideal if you could retain the siding and repaint when needed. The wider, horizontal boards are more common on houses built from the 1950s and 1960s. Narrower, horizontal boards were common during the late 1800s and early 1900s.

If your house has vertical boards, stucco, or some other type of siding, you may want to continue with the same type of material.

Sometimes additions to historic houses look best if the material used to side the addition contrasts with the original. This gives the addition its own sense of time. For example, a stucco addition with wood frame accents could look very attractive with a lap-sided house.

Dealing With the Building Code

The primary purpose of the building code is to help people build structures that are safe. Of course, what we consider safe today is different from what was considered safe 100 years ago. Instead of requiring that all historic buildings be retrofitted to today’s standards, the County can arrive at a compromise in some situations.

Buildings that are officially designated as historic landmarks qualify for exemptions from the building code in some circumstances. Retaining an historic staircase that is too steep to meet today’s standards is just one example of a commonly requested exemption from the building code. Of course, the goal of historic preservation cannot be more important than the goal of creating safe living environments, but with some creativity, a solution that meets both goals can be formulated.

If you have questions about exemptions from the building code for your specific project, please contact our office and ask to speak with the historic preservation staff person.

Contact Us

Historic Preservation
Main: 303-441-3930

Courthouse Annex Building

2045 13th St.
Boulder, CO 80302


8 a.m. to 3 p.m. Monday, Wednesday, Thursday
10 a.m. to 3 p.m. Tuesday
Map and Directions

Mailing Address

Community Planning & Permitting
Historic Preservation
PO Box 471
Boulder, CO 80306
Historic Preservation website