Thursday, July 16, 2009


ABOVE: The gallery in this classically-styled home features a barrel-vault ceiling and terminates in double doors that look upon a rose garden surrounded by a colonnade.
In architecture, circulation means the pathways through a floor plan. These pathways are how we experience architecture; the design of these pathways has an enormous effect on the success or failure of a plan. Circulation spaces ought to be as interesting as any other part of a building. There are always unique opportunities to make circulation interesting.
ABOVE: This residential gallery uses extra width, creative lighting, and an integral focal point to make the architectural experience interesting.
Obvious pathways include hallways (horizontal circulation) and stairs (vertical circulation). But every space we are able to occupy is part of the circulation system of a building. Halls can be expanded to become spacious areas like vestibules, foyers, galleries, arcades, and colonnades. Vertical circulation can include elevators and escalators. Less obvious pathways are the spaces between and around furniture: the spaces in rooms where people are likely to walk. All of these variations on circulation are important aspects of architecture because it is through movement that we enjoy architecture as a three-dimensional experience. Without movement, architecture is merely a stage set: entertaining to look at, perhaps, but with no direct relationship to the user.

ABOVE: This hallway uses at least five architectural "tricks" to make the long traverse interesting: skylights, level changes, art niches, generous width, and terminating the vista with a window looking out to a private garden. (Photo by Cynthia Schlaer.)

Good circulation is essential to successful architecture. Like the flow of blood in a body, circulation works best when the route is clear and unobstructed. After all, how can you appreciate beautiful spaces if you don’t know where to go or you’re constantly bumping into obstacles? When we confront people with an obstacle course, their eyes are on the obstacles, not the architecture.

ABOVE: Note how this master suite accomodates circulation and furniture without conflicts.

A floor plan with good circulation makes every square foot of space work efficiently and gracefully. Good circulation does not necessarily mean that the shortest path between two points is best. It means that the most architecturally rewarding path between two points is preferred. ABOVE: Vertical circulation handled with sweeping stairways in traditional and contemporary homes.

BELOW: A simple organic shape (like a snail shell) makes the vertical circulation seem inviting and effortless.

When designing any building, an architect must consider circulation and furniture placement simultaneously. Plans in which furnishings and circulation work in concert optimize the chances of people being able to move easily and comfortably. When people feel at ease, the experience is more likely to be pleasurable. A master bedroom, for example, must have a logical place for a bed. A bed wall should be opposite the entry to a bedroom. A bed can be a beautiful piece of furniture and this is an opportunity to display it, rather than make it an obstacle. In speculative housing an awkward bed location would be bad marketing; in any home it is bad design. Art niches, television walls, and natural views are among the conditions that must work with the circulation patterns and furniture arrangements. Any furniture grouping – whether in a living room or a bank lobby – should have a place to be without compromising circulation. Circulation forced through such groupings is like a rude interruption to a private conversation.
ABOVE: This courtyard home is entered through a small gate house (left) that leads to an enclosed path (right) bridging a swimming pool and leading to the front door. This sequence of events engages our curiosity and imagination to make the space inviting.

Traffic patterns are most effective when clear, logical, and unambiguous. However, that doesn’t mean they need be boring. Walking through a work of architecture is a sequence of events, and every event can be interesting. In a well-designed floor plan, every event reinforces the theme, variations, and development of the overriding functional requirements and esthetic purpose. Circulation spaces should be designed as meaningful parts of the whole.
Open planning is modern architecture’s gift to spatial perception. Narrow, dark hallways are a relic of the past. In many buildings, efficient space planning can make hallways all but disappear, blending the circulation spaces with functional spaces, transforming hidden square footage into open, perceived space. This borrowing between spaces adds interest and thereby increases value. When circulation must exist independent from the main spaces because of privacy or security, the architect still has many design tools available to keep things interesting. When the budget allows, foyers can be generous, halls can be designed as galleries, and stairs can be compelling focal points. Circulation need never interfere with furnishings or function. The challenge is to find interesting and lively transitions from one space to another. Space flows naturally and effortlessly when circulation is an integral part of architectural design. ABOVE: Three views of a residential hallway consisting of interlinked galleries topped by pyramid skylights and clerestory windows.

BELOW: Plan showing how the galleries are staggered to set up a dynamic path through the home.In mild climates we have additional opportunities to make circulation especially interesting. Good weather is an encouragement to integrate indoor and outdoor circulation. Connections between various parts of a structure could be a series of vine-covered, open-air trellises rather than indoor corridors. In colder or wetter climes, this might be impractical, but in Las Vegas, for example, we recently designed a home where all the hallways are outdoor trellises. Yes, there are days when heat or winds are an inconvenience, but the opportunity to enjoy the natural environment on an everyday basis far outweighs those negatives.
ABOVE: This Las Vegas home is a series of pavilions with the circulation system accommodated by outdoor trellises and broad roof overhangs.
Every part of a building should enhance the architectural experience. No less important than any other part is the space we devote to circulation: the space between the spaces. ABOVE: Narrow halls, even in the most affordable homes, can be enhanced with art niches. This display area was constructed within the constraints of a 2x6 wall.

All photos in the above article by Rob Munger unless otherwise noted. Architecture by Michael Knorr & Associates, Inc.

Monday, July 6, 2009

A Letter to the Mayor

The following letter was sent to Denver Mayor John Hickenlooper last week following presentations by the Planning department regarding proposed zoning code changes. I reproduce it here in response to interest expressed by local architects, builders, Realtors and property owners. The proposed changes follow a nationwide drift to reduce property entitlements. The trend is to make redevelopment of private property more difficult, more restrictive, and less creative. (See "Malibu Dreaming" post, March 31, 2009.) I apologize to readers outside of Denver who may find this discussion of zoning rules a bit arcane, but be aware it could happen in your neighborhood.

I do believe the final draft of the new zoning changes will be less Draconian than the current proposal. How much better is difficult to predict. To keep abreast of the massive code revisions (hundreds of pages) visit You can also find contact information for the mayor, council members, and the Planning department at this site.

2 July 2009

The Honorable John Hickenlooper
Office of the Mayor
City and County Building
1437 Bannock, Room 350
Denver, CO 80202

Re: New Zoning Code

John Hickenlooper:

I have attended several meetings and workshops conducted by the department of Community Planning and Development regarding the new zoning code. The Planning department emphasizes that the new code is “a work in progress.” Work has progressed for some time with each rendition of the proposed code introducing additional troubling concepts and details. Since the shape of the code is now becoming quite specific, I feel it is time to register deep concerns regarding negative architectural and economic impacts the new code will have.

The proposed code is lengthy and complex, covering, as it must, very different neighborhoods and conditions. The observations in this letter are limited mainly to the S-SU-B and E-SU-D designations and specifically as they apply to the University Hills neighborhood. These are limited examples. Please be aware that other parts of the proposed code are similarly flawed.


S-SU-B is a residential district. The blocks of University Hills north and east of Eisenhower Park fall under this new category. Spokespeople from Planning assert that the current R1 zoning (single family detached) would remain intact and thus “preserve current entitlements.” In fact, as written, S-SU-B would change current entitlements by significantly reducing the allowable size of future development. This will negatively impact property values and, by extension, the future tax base of the City and County of Denver.

Lots in this neighborhood vary considerably by orientation and shape. There is no typical lot, but a common size is 60’ x 155’ (approximately 9300 square feet) as illustrated below. Prior to February 2003 one could develop 50% of such a lot, including garage, porches, and any covered areas:

1 Zoning Restrictions Before 2003

This entitlement allowed for several features of proven value in the marketplace: a three-car garage (albeit with a “tandem” space on this narrow lot), the option of a single-story plan, and room for outdoor covered spaces.

These possibilities significantly changed with “Quick Wins II” in 2003. Those changes, currently in effect, limited developable area to 37.5 per cent of a lot:
2 Current Zoning

On the example 9300 square foot lot with similar garage and porch allowances, the main floor living area is reduced to 2300 square feet. The possibility of a single-story plan is sharply curtailed and two-story plans become more likely. Of course, smaller lots (of which there are many in the neighborhood) have less buildable area. Current zoning restrictions also sharply curtail the size of second floors, development in the rear one-third of a lot, and the bulk of structures. Nevertheless, the University Hills neighborhood has seen a renaissance of new housing in recent years under these restrictions.

The proposed zoning reduces the developable area again. The new maximum is a miserly thirty percent. In print, this is an abstract number. On actual lots the effects are Draconian:

3 Proposed zoning with 30% maximum lot coverage.

To yield 1900 square feet of living area one would be required to forgo a third garage space and reduce the amount of covered porches or patios. Single-story plans or main floor master suites become more difficult. Remember, the illustrated example is a relatively large lot by urban standards; even so we encounter difficulties meeting the demands of market-oriented housing. Imagine how problematic this becomes with smaller parcels. Big segments of the market would be jeopardized by these conditions: growing families who require more bedrooms and additional car shelter, older or physically challenged people who don’t want to climb stairs, and the affluent market that simply demands more space.

Property owners already experience negative impacts from previous zoning changes. The proposed zoning exacerbates the situation by shrinking allowable development. The following graphic illustrates the diminishing returns:

4 The Incredible Shrinking House

There are many other detrimental restrictions in the proposed zoning. Note in the above illustration how the allowable driveway shrinks to a ridiculously small area. The proposed rules would make servicing two-car garages impossible.

Also worrisome are the proposed height and setback changes. Current rules allow for a two-story house that could offer the style, amenities, and architectural volume to make it competitive in the broad marketplace. The proposed zoning drastically reduces width, overall height, and floor-to-ceiling allowances. Two story homes would lose 4’ to 9’ in height (depending on lot width). Single story homes would lose 10’ to 15’ in allowable height. Increased side yard setbacks further reduce the street presence of new construction. Houses already limited by Quick Wins II are further diminished in size and curb appeal.

5 Proposed zoning eliminates shaded area on a two-story house.

6 One story homes would fall under additional height restrictions.

The Planning department makes a point of claiming that architectural style is not affected by these changes. However, the restrictions channel design into squat structures with low-pitched roofs and low plate heights. Furthermore, even more severe limits on flat-roofed structures and single-story plans make modern or inventive styles impossible as shown in the two examples below:

7 Flat roof structures are singled out; the red-shaded areas would not be permitted.

8 Innovative architecture is problematic under the proposed limits; shaded areas not allowed.


A second University Hills district, described as “urban edge”, falls to the south of Eisenhower Park. This E-SU-D designation is distinguished by square blocks with alleys. Otherwise, it is similar to the rest of University Hills in appearance and variety. Yet some of the restrictions here are even more severe. Rear setbacks are now proposed at 50% to 60% of the lot depth and allowable driveway features (such as circular drives) are mathematically eliminated. If the intent is to preserve the morphology of the neighborhood, the restrictions do not accomplish this. For example, an actual existing older home of 1500 square feet would be impossible to reproduce under the proposed rules. Square footage, width, and architectural offsets would all be in violation. Approximately 200 square feet would be lost in the following example:

9 An older existing home not allowed under the new rules.


The response by Planning to these criticisms in public meetings has been that the restrictions are in flux and will be “calibrated” based on neighborhood input. My concerns are more fundamental than calibrating numbers. A catch phrase from Planning describes the zoning revisions as “form based” design. This means, by my understanding, that for every designated district the shape, size, offsets, and massing are predetermined by a matrix of dimensions. At the same time, we are told that these prescriptions do not regulate architectural style. The contradiction in the last two sentences should be apparent. Architectural style is not limited to frivolous details applied to predetermined shapes. Architecture is precisely a result of form.


This letter has focused on a limited portion of a lengthy document. I want to emphasize, again, that there are numerous examples throughout the proposed code where architecture and development possibilities are limited more like a covenant-controlled community than a vibrant urban center. Section 3.3.2, to cite one final example, gets into issues of architectural “articulation.” It describes (in detail) “horizontal articulation elements,” the “base, middle, cap” of a building, and even the dimensions of eave projections. There are whole swaths of architectural styles compromised by such picayune micromanagement.

The proposed zoning moves in the direction of freeze-drying our neighborhoods, as if they are already the best that they can be. This only stifles new ideas and discourages monetary investment. It will put Denver at a competitive disadvantage for tax dollars. It will limit the number and diversity of people attracted to our redeveloping neighborhoods. Most detrimental to current residents is the damper it places on existing lots and the possibilities of enjoying the full potential of our property.

As an architect, I would like to see every aspect of the built environment in perfect harmony, well proportioned and beautiful. But this works best when it happens organically and with variety. By allowing great latitude in the system, mistakes may happen and things may not always look the way we want them to. However, in balance, maximizing creative freedom also invites exciting innovations that just may point the way to a better life for everybody.

The proposed zoning code heads in the wrong direction. I trust that the mayor’s office will closely examine these impending policy changes. If you or a member of your staff would like to discuss these ideas or other aspects of the code in more detail I am available anytime.


Michael Knorr

Friday, July 3, 2009


I subscribe to a lot of architecture magazines. Some are aimed at a professional architects, others are general audience magazines. Surprisingly, one of the best architecture periodicals is not specifically about architecture. Hospitality Design, published monthly by Nielsen Business Media, New York, is primarily for hotel executives, marketing directors, and interior designers who need to be aware of what is going on in the hospitality industry.

Hospitality Design reports on hotels, casinos, spas, resorts, and restaurants of all sorts. Of course, architecture is a big part of this. Even when restaurants are built within existing structures (as in a casino, for example) many of them are so large that they take on an architectonic scale with all the accompanying concerns of structure and design. Hospitality Design devotes a lot less ink to technical analysis than do professional architectural journals. There is little architectural jargon but plenty of lush photography. Featured projects investigate corners of the architectural world that most people don’t see except on vacation. Even though the projects are retail or commercial, many of the photographs provide inspiration for custom homes and private offices. After all, spas and hotel rooms require the same fixtures and furnishings as a home. The materials and products in Hospitality Design would be of interest to anyone who appreciates design. Even the advertisements highlight things you do not see anywhere else. I look forward to every issue, always heavy with pictures and short on words.

The ideas in Hospitality Design run the gamut of price and style. What makes the hospitality industry interesting, and, by extension, provides rich material for this magazine, is the fact that things change fast in restaurants and hotels. Las Vegas is a good example. A restaurant in a resort hotel has a shelf life of three to five years. After that it is old news and must be remodeled and rebranded. Everything needs to be fresh for a fickle audience. New restaurants must offer innovative environments that haven’t been seen anywhere else. This aims to pique our interest and draw us in. Word of mouth – the buzz – is the best form of advertising. In the hospitality industry, good design is good business. Design matters here in a down-to-business analytical way. In one sense this is refreshing because usually we’re reduced to abstract concepts to justify good design. Hotels, restaurants, nightclubs are stage sets for the customers they serve. People go to these places to feel important or glamorous or to experience some specific emotional resonance. The hospitality industry has always understood this intuitively. My favorite examples of this understanding are the works of Morris Lapidus. He is famous for some of the great Miami Beach hotels of the 1950s, among them Fountainbleu and Eden Roc. Dismissed as kitsch by serious architecture critics when they were built, they have since been revisited as brilliant examples of postmodern delight with a clear understanding of the theatricality that people craved – at least in their fantasy vacation spots.

To accomplish all of this theatricality the budgets for these venues are astonishing. I am always amazed that after spending many millions of dollars on a new restaurant the owners can still make it up in profits. And have enough money to do it all over again when time comes to remodel. Of course, they are not all successful. My father, who knew many restaurateurs, often told me the restaurant business was the riskiest around. I never aspired to be part of it. But we can all enjoy the lively design forays that the hospitality industry makes as evidenced in the pages of Hospitality Design.

Some of these places are very elegant and serious.

Others are whimsical, like this nightclub in New York.

The bubbly glass spheres and LED light display are Bruce Goff on steroids and a big budget.