Pops and scrapes, new Boulder regulations, Part I

The City of Boulder has passed sweeping new regulations that will effect a large number (around 13,000) of single-family homes across the city.  These new regulations become active at the first of the year and the impact on building projects will be significant.  Much of the discussion and controversy over these regulations concerned a reduction in the allowable building area (Floor Area Ration, FAR) that is to be applied on a sliding scale with smaller lots getting a greater percentage of allowable building area.  However, it is the physical location and topography of the given lot that may have a much greater influence over the allowed building area, not the FAR.  Over the next few weeks, we are going to post some analysis and review of what these new regulations will mean  for the different neighborhoods of Boulder.


East-West running streets in Boulder, typical of mesa areas:  south Boulder along Vassar and Lafayette , Chautauqua south of Baseline, Mapleton Hill, north Boulder north of Iris.  The streets predominantly run east-west because of the east-west running topography.  Not coincidentally, these lots are larger than typical (yellow is over 8,000 sf, orange over 10,000 sf).  As the existing solar shadow ordinance is preferential for this orientation because the shadows cast either into the street or onto the owner’s property, the new regulations laid over the solar ordinance have a smaller impact in these areas.

north south

North-South running streets in Boulder, typical flat topography:  south Boulder between Table Mesa and Viele Lake, Martin Acres, University Hill, Newlands.  These streets run predominantly north-south  and more strictly adhere to a rectangular grid.  These lots tend to be smaller (dark blue is less than 6,000sf, cyan is 7,000 sf).  The ability to add on to these properties is greatly limited by the existing solar ordinance because the house’s shadow is cast upon the lot’s northly neighbor, quickly violating the ordinance with an added second story.  The additional new pops and scrapes ordinance (Compatible Development) has much greater impact on these areas of the city as the lots are already smaller and more challenged by the solar ordinance.

Over the next fews posts we are going to look at how the new and existing regulations combine for unintended consequences and produce results that prejudice some areas of the city over others, and influence the type of architecture that may be sympathetic with the regulations.  Surprisingly it is not the limited FAR that most directly and negatively impacts most properties, but the associated new regulations that cause the most difficulties.  Along with the new sliding scale FAR regulations the City ordinance contains:

1.  Maximum building coverage regulations

2.  New ways of calculating floor areas for basements (this makes a huge impact on walk-outs)

3.  Sideyard bulk plane regulations

4. Sideyard wall articulation requirements

Like all real estate, the most important thing is “location, location, location”, and so it goes for these regulations.  It is not the restrictions themselves, but how they impact specific properties in the real world, with topography, orientation, architectural styles, etc. that will have consequences unknown.

As we are a strong proponent of very site-specific architecture, of design that is grounded in a place, the potentials of the new regulations may begin to feel like an unwanted collaborative partner in the design process.

See the City’s website on the history of the ordinance and its study materials:


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