Thursday, October 25, 2012

Sustainable City Services: Housing

Sustainable City Services: Cycle of Housing Stock and Age of Residents

When looking at city services, do the needs fluctuate from decade to decade or half century to half century? For example, robust school enrollment followed by declining enrollment and then a rise in enrollment again. With the approaching "grey tsunami," the need for senior services will greatly increase. However, in roughly 40 years when the Boomer generation is mostly gone the need for the senior services will be reduced.

Littleton, located near Denver, has done a good job in making the city an enjoyable place to live. Many residents want to stay in the city as they age. However, a number of residents have expressed a desire to downsize their larger houses as they become empty nesters. The problem is limited housing options within city limits, much less within the family neighborhoods that they have grown to love. Thus, to downsize, they would have to move to a new neighborhood or out of the city. The challenges that Littleton faces is becoming more widespread among cities. 

This lack of housing appealing to older adults appears to be a major reason for school enrollment fluctuation. The cycle of young families moving into newly constructed neighborhoods is reflected in school enrollment increasing. As the families age, the kids graduate and move out of the house, but the parents cannot downsize, which keeps the family house under occupied for 10, 20, 30 plus years. Can schools weather the long cycles of housing turnover to young families?

As a case example, the graph below shows the fluctuation of Littleton Public Schools enrollment.1 In the last few years, Littleton did close 2 schools due to falling enrollment.

The second graph shows the cycle in average household size, assuming a built-out community where people do not want to move out as they age. Analogous graphs would be needed for non-land locked communities still expanding in housing stock and population.

In this graph, the yellow bars represent time periods in which the city needs to provide more services and infrastructure for families with kids, such as schools and kid oriented events. The grey bars represent time periods in which the city needs to provide additional services for older residents such as shuttle service to grocery stores.

Some research indicates that in locations not having enough families in the neighborhood has some undesired consequences such as bus routes reduced when too high a percentage of passengers qualify for reduced senior rates and grocery stores relocate. Fluctuation in needed services is expensive for cities. A more constant average household size makes providing services easier. The following are housing considerations to help provide an environment for a more stable average household size.

Potential Solutions for Existing Neighborhoods:

Modifying existing neighborhoods is one of the harder challenges for improving the city's housing stock. The following ideas are small scale and should allow existing neighborhoods to evolve over time. For all of these options, there can be too much of a good thing. The recommendation is to limit the density of each housing type.

  1. Group housing typically looks like a single-family residence from the outside and located within single-family neighborhoods. Inside, each resident has a private bedroom and possibly a private bathroom. The rest of the house is common space shared by all residents. A certified nurse or care giver may reside on site or visit regularly. Not all zoning codes allow group housing, but allowing group housing will provide more options for older adults.

  1. Accessory dwelling units (ADU) allows a 2nd unit to be built on a lot with an existing house. The ADU may house a recent college graduate looking for a job or an elderly parent. ADUs can also be rented to non-family members. Again, not all zoning allows ADUs. However, including ADUs in the housing mix can increase options for families as well as provide additional rental options.

  1. ADUs can be taken to the next level by allowing the ADU to be sold independent of the main house. This can provide additional flexibility for the homeowner. To encourage more accessible housing, zoning could allow the minimum lot size to be ½ the current size provided that a "universal design" house built on each ½ lot. This would allow a homeowner in an existing single-family neighborhood to scrap the house, replace with 2 universal design houses, and potentially live in one of the houses while selling the other house to pay off the construction loan.

For New/Infill Projects:

For new or lager infill projects, cities could require variety in the housing sizes to help achieve a more constant average household size over time. These new projects present opportunities to make a significant impact on the future direction of the city.

  1. For a mixed generational neighborhood, every 3rd or 4th unit should be a different size. For example, if the development is primarily a family neighborhood with 3+ bedroom houses, the "other" houses would be smaller such as patio homes for older adults. The housing mix should attract singles, couples, families with children, and empty nesters.

  1. For multi-family units, require a mix of 1, 2, and 3+ bedrooms to accommodate all family sizes. All too often, multi-family is not family-friendly. This needs to change to allow for more affordable family size housing options. Accessibility is big for older adults, so ensuring an adequate mix of accessible units is also very important.   


One of the goals is to support people living and aging in their city. Thus, aging in neighborhood is balanced by optimizing community resources in that larger houses are primarily occupied by larger households. When downsizing, hopefully the person or couple is literally only moving a few feet to a familiar house, thereby minimizing the stress associated with moving. A new young family now has the opportunity to move into the city and live in the larger house.

Thursday, September 13, 2012

Sustainability Toolkit for Family Friendly Cities

Our slides for "Sustainability Toolkit for Family Friendly Cities" presented at the Downtown Colorado Inc conference September 13, 2012 are located at:\SustainablityToolkitFamilyFriendlyCities.pdf (11M)

Outline of presentation:
  • Human Sustainability Introduction
  • Motivation for Multi-Generational Planning
  • 12 Guiding Principles for Family Friendly Cities
  • Mapping of City Family, Business, and Resource Centers
    • Case Example for Littleton, CO
    • Case Example of Mapping for Denver Metro with Light Rail to Connect Family and Business Centers
  • Sustainability Toolkit:
    • Social
      • Multi-Generational Public Spaces
    • Housing
      • Multi-Generational Housing
      • Affordable Eco-Friendly Living
    • Mobility
      • Multi-Modal Streets
      • Personal Transportation Hubs
    • Education
      • Purposeful Education
    • Universal Resources
      • More Land for Living and Food
      • Water Scarcity Leads to Abundance
Each Toolkit item includes a description with design considerations, benefits for various stakeholders, and case studies.

Charging Up Your City

6 vehicle spaces converted to 12 LSV spaces with a new picnic area

Charging Up Your City

Do you want to charge up your city? The following are some thoughts for charging up your community's excitement level, charging up your electrical devices, and charging up your economy.

The Denver Post June 24, 2012 article, “Getting a charge out of new law,” described a new state law effective in August. This law will allow anyone to sell electricity. One potential application is for electrical charging stations spread throughout the city. The law is aimed at charging electric vehicles, but the charging stations could be used to charge any electrical device. Consider for example, a charging station at a park. The same station could be used to charge an electric vehicle as well as a laptop, cell phone, or tablet.

For the owner of the charging station, this could be an additional source of income, be it the government entity that owns the park or a business owner with some unused rooftop space for solar panels.

The electric vehicle owners will have convenient, reasonably priced electricity to reduce "range anxiety" concerns. Refill costs may be “$4 instead of $40 or more for a tank of gas.” With the reduced emissions from the electric vehicles, everyone will benefit from the cleaner air. This could be a win-win for all stakeholders.

As much potential as the reselling of the electricity holds, this is only the tip of the iceberg, so to speak. The big impact could come from combining the charging stations with low speed vehicles (LSVs).

Of the many types of vehicles permitted on the road today in Colorado, low speed vehicles could be an up and coming mode of transportation. LSVs include neighborhood electric vehicles and golf cars (golf carts with head lights and brake lights). LSVs are already permitted on roads with a speed limit of 35 mph or less and can cross roads with a higher speed limit at intersections.

For car drivers, the LSVs are significantly lower cost. For senior drivers, they are also safer to operate. Thus, LSVs can provide mobility options for later in life.

The real potential of LSVs is the fact that the vehicles are one forth the size of traditional gas powered motor vehicles. Thus, if there were enough users of LSVs, the city could restripe a few parking lots and get a 4 fold increase in parking. Or, some of the space could be reclaimed for non-parking uses. For example, consider the economic impact of this reclaimed land used for additional outdoor seating at a restaurant. Developers could use this extra space for a larger building footprint, which may translate to more sales tax revenue or property tax revenue.

There are a number of actions that planners can take:

1)    Promote the use of LSV noting the benefits such as lower cost, safer, lower emissions, smaller size, and more non-parking space for developers/landowners.

2)    Make sure that all zoning and ordinances allow for the charging stations and solar panel installation.

3)    Make sure that parking requirements are properly adjusted for LSVs.

4)    Create a connectivity map of the city noting key destinations such as stores, parks, schools, and residences and roads with speed limits <= 35 mph. If the key destinations are not connected, see if there is an easy way to add the missing connectivity such as changing a speed limit from 45 to 35 mph.

5)    Determine how to best reallocate the reclaimed land to benefit the city and its residents.

NOTE: This was also published in APA Colorado Q3 newsletter

Wednesday, September 5, 2012

Roofs as Economic Generators

Creating and improving the economic potential for communities is always beneficial, but especially with the current great recession. These two areas can be addressed by looking up. As an exercise, go to a tall building in the city, look at a Google maps view of the city, rent a hot air balloon ride, or in some way look down at your city. In most cases, there will be a number of big flat roofs. These roofs are a missed opportunity for economic growth of the community.

Some potential economic generators for rooftops include:
  • PV Solar Panels
  • Green Roof
  • Edible Green Roof
The PV solar panels would, somewhat obviously, generate electricity that the building owner can use to reduce their electric bill. In the extreme case, there will be a surplus of electricity that the building owner can sell back to the local utility company and actually make money instead of just saving money.

The state of Colorado recently passed a law making it much easier for non-utility companies to resell electricity. For example, the building owner could set up electric vehicle charging stations on their property and make some income from reselling the electricity.

New Jersey and California are using public-private partnerships to get solar panels installed, for example, on school rooftops.

If enough rooftops install solar, and the region is getting close to exceeding current electric plant capability, these rooftop electric generators could prevent the region from having to invest in a new power plant, thus saving everyone an electric rate increase to pay for the new plant.

In addition to reducing urban heat islands, thereby making the city more people friendly, green roofs can significantly reduce the building's heating and cooling needs. One on-line estimator provides some estimates for the cost savings. Some example yearly cost savings:
  • Arizona State Capital Building = $24,266
  • The Pentagon = $1.1 million
  • Walmart SuperCenter in Bentonville, Arkansas = $179,300
Hopefully, this saved money will work its way back to the city and the residents. The concept can also be used for city buildings and the saved money can be used elsewhere within the city budget.

Extending the heating and cooling benefits of green roofs to edible green roofs would have the additional benefit of increasing local jobs as well as local food. Some interesting examples of large rooftop gardens are coming from New York.

Rooftop farms are in the midst of a boom here in New York City
Driving that boom – at least in part – is New York City’s Zone Green. Proposed amendments to Gotham’s zoning code that continue an inexorable march through the approval process, Zone Green would permit solar panels, green roofs, storm water systems, skylights and other green features on New York City buildings, despite existing restrictions within the 1961 code. Specifically with respect to rooftop farms, Zone Green would allow a waiver of floor area and height limits for greenhouses on top of non-residential buildings.

A second rooftop garden example comes from Brooklyn. This one is a hydroponics greenhouse on top of a warehouse rooftop that is harvesting 365 days a year.

… hydroponics allow the urban farm to produce about 10,000 heads of lettuce a week – roughly 100 tons a year.  The controlled environment agriculture uses 10 times less water and 20 times less land than traditional harvesting methods.

“We’re producing crops and delivering it within 24 hours, definitely making it the freshest product on the market – the shelf life is passed on to the consumer,” said Nelkin. “By being the freshest, it’s also the most flavorful and nutritious.”

Another agricultural example comes from Denver. The Brown Palace hotel in downtown Denver has added 4 bee hives and 65,000 bees to their roof and "can produce upwards of 150 pounds of harvestable honey every summer". "Marcel Pitton, managing director of The Brown Palace, said the honey is like 'liquid gold' for the hotel. The honey is used in the restaurant kitchen and as the basis for a lavender honey soap and a local beer, made with the Wynkoop Brewing Company." The article states that the beekeeping program started "three years ago, after the city passed an ordinance in 2008 allowing hobbyists to own hives." Thus, emphasizing the importance of planners working with the city to make the conditions appropriate for roofs to become economic generators.

Rooftop gardening can be practical with the only change to the roof being the addition of light weight planters. In 2011, "450 urban agriculture planters were installed on the roof of the Palais des congrès, allowing three partner restaurants (Crudessence, the Palais’ catering service, and Intercontinental hotel) to learn more about the basics of market gardening in cities and offer a wide variety of produce on their menu for those who want to eat locally and in season." (Source article)

As one example, Biotop has an edible roof integrated system for growing food. It is lightweight and can be installed on an existing roof without structural modifications. The Montreal Convention Center installed this system over the summer during the Ecocity World Summit 2011. The food grown went to local restaurants.

Here are 7 brainstorm ideas for how cities can help to turn the city's unused rooftops into economic generators:
1)     Comprehensive Plan and Sustainability Plan
2)     One Page Briefs
3)     Free Advertising
4)     Zoning and Ordinances
5)     Open Space Reduction for Green Roofs with Additional Credit for Growing Food on Roof
6)     Make it Easy
7)     (Last Resort) Unused Rooftop Tax

First, make sure that the city's Comprehensive and Sustainability Plans include using the rooftops in creative ways, so as to encourage economic benefit to the building owner as well as the city and its residents.

Second, create one page briefs. These would be short educational brochures to inform the building owners of the potential cost savings or income potential from different roof uses. Logistic, cost, and other "barriers to entry" should also be noted to help the building owner decide if one of the options is not appropriate for their building.

Third, do some free advertising for building owners that implement a rooftop economic generator. For example, highlight the business on the city web site or in the local newspaper. Use the company as a case example highlighting what it took the company to implement the economic generator. This could be framed as this month's "Rooftop Economic Generator Winner". Over time, revisit the company and have another article, or award, highlighting the economic benefits that the company has generated from the rooftop effort.

Forth, make sure that all zoning and ordinances allow these economic generators on the roof. For example, see New YorkCity’s Zone Green above. Also, for the edible rooftops, allowing food stands to be set up around the city would help the food growers to sell the produce to residents. Wheat Ridge, CO claims to have one of the most liberal food stand policies in the U.S., allowing food stands almost anywhere: "This ordinance updated the city's regulations so that community garden (under the category "urban gardens"), farmer's markets, and produce stands are now allowed in any zone district."

Fifth, which is a subset of Zoning and Ordinances, is to allow green roofs to count towards open space requirements. This will give developers more ground space for development, increasing their profit. This should also increase city tax revenue (sales tax for increased business size, increased property tax from larger building/more housing units).

Sixth, make it easy. For the most part, the building owner is most likely not concerned about trying to run a second business. A big box chain store will not want to change their focus. A small mom and pop business may already be stretched on available time and brain power. To overcome this, the city can do some of the leg work for the building owners. For example, consolidate all needed forms and steps into a pre-packaged form. Consider the case of an edible green roof, the city can have on hand a leasing contract that the building owner can use with the farmer that wants to lease the roof space. The building owner can then use these forms verbatim, or modify them as desired. As a case study, look at Santa Cruz. They have 7 pre-approved ADU packages that, if selected by the home owner, allows for shortening the building approval process.

Seventh, create a new "unused rooftop" tax. This should only be used if all other means to encourage effective rooftop uses fails. The concept for this tax is that if a commercial building owner with a flat roof does not implement an approved economic generator use for a "sufficient" percentage of their roof, than the building owner has to pay a tax for this unused space. If the building owner does implement an approved use for enough of their roof, then there is no tax.

By looking up, cities can "create" additional space to plan for the future. With some creating thinking, the unused space rooftops in the city can become an economic generator.

Wednesday, June 13, 2012

Speaking at APA Colorado Conference

We have been accepted to speak at the APA CO conference in Snowmass Colorado ( The talk is scheduled for the afternoon of Fri. Oct. 5, 2012. Title: "Babies & Boomers - Assessment Tools to Create Livable, Sustainable Communities for All Ages"

This is a joint presentation with the DRCOG representatives who will discuss the Boomer Bond project including the city staff based self-assessment and toolkit items to better prepare the city for the pending significant increase in senior population.

HLP will expend the discussion to include all ages. We will present our city ranking system, which is a data driven system using information from the internet. Our focus includes eco-friendly, sustainability, and designing for all ages.

Monday, April 30, 2012

Speaking at Downtown Colorado Inc. Annual Conference

Jenny has been accepted to present at the Downtown Colorado Inc. annual conference in Golden Colorado ( The talk is currently scheduled for Thur. Sept. 13 9:30 am. The talk title is "Sustainability Toolkit for Family-Friendly Cities". We are hoping to present a number of innovative ideas to help cities be more eco and family friendly by designing for the youngest to the oldest resident.

Thursday, January 12, 2012

Personal Transportation Hubs: Supporting Alternative Transportation

Note: This blog post is being written from a U.S. perspective for U.S. cities. We do realize that much can be learned from other countries.

A growing number of reports indicate that some demographics, especially seniors and millennials, are interested in moving back to the city centers. Other reports promote the benefits of such "hot topics" as: increased densities, mixed-used, transit oriented developments, etc.

To support all of this, we should expand our transportation options. Granted, options such as Bus Rapid Transit programs similar to what was implemented in Curitiba and is being started in Chicago and high speed trains are good. Our proposal is to consider creating "Personal Transportation Hubs.”

A Personal Transportation Hub is a shared resource for a group of people. The resource being shared is various transportation vehicles. These could include cars, bikes, scooters, and "electric vehicles" (more on this later). This idea is inspired by some reports indicating that millennials are more interested in renting than owning. With this train of thought, more compact developments could gain space and cost savings by creating a Personal Transportation Hub of shared vehicles. The Personal Transportation Hub would be for members only. The members could reserve and check out any vehicle that is in the Personal Transportation Hub.

Consider, for example, a cohousing development with 40 to 100 units. Traditional design would indicate that 1-2 parting spots are needed per unit with some spaces for visitors. With a Personal Transportation Hub, car sharing could reduce the number of parking spaces per unit by eliminating the need for a second car, or in some cases, their primary car. Thus, there would be space savings, as well as cost savings to residents without the worry of car maintenance or insurance. If managed well, the Personal Transportation Hub could provide the members access to specialty vehicles such as a pickup truck for home chores or a convertible sports car for date nights. Hopefully, each member would indicate their destination to allow others to see this with the hope of encouraging car pooling. For example, consider when someone is going to the grocery store. A senior Personal Transportation Hub member who can no longer drive may be very appreciative of this car pooling opportunity.

Consider again a cohousing development with multiple generations. Considerable space is needed to allow everyone to store their personal adult bikes and especially the kid's bikes. At any one time, only a fraction of the bikes will be in use. Replacing the individual bikes with bike sharing stations will save garage/storage space for the housing development as a whole.

Borrowing from European experience, it would seem that as U.S. cities become more compact that scooters will become more and more acceptable to use. Scooters would then be a natural component within the available transportation options.

The "electric vehicle" inclusion would require changes to our transportation infrastructure as the "electric vehicle" we are referring to is a golf cart. Compared to a gasoline powered car or the new hybrid and fully electric cars, golf carts are inexpensive. The golf carts are also smaller, so it will be easier to find parking than a full size car. The idea is that the golf carts could be used for short trips by a person that is not physically able to use scooters. Consider a senior going to a doctor appointment or grocery store or a mother with kids going to a park or museum (safety improvements would probably be needed for the kids to be passengers in the golf cart).

Currently, U.S. roads do not allow golf carts. The thought is to change current regulations and designs so that the golf carts are allowed. For example, consider a Complete Street-like design. Another, option to consider for retrofitting existing city infrastructure is to convert a road that has one lane in each direction. These roads could easily be converted to have 1, one-way lane for cars with the second lane being dedicated to alternative low-speed vehicles such as the golf carts, low speed scooters, and bikes. Hopefully, these alternative vehicle lanes would be safe enough so that families could also use them for bike riding with young kids.

A consideration with golf carts is inclement weather. One low cost option is a clear plastic "tarp" (specifically designed for golf carts) that goes over the golf cart. This can minimize the effects of rain, but is not overly "pretty" looking and does not help with more sever weather. Doing an internet search, the below hard shell golf cart was found. It this becomes popular, more options would likely become available.

For a properly designed city, essential services such as doctor offices, grocery stores, parks, museums will be in relatively close proximity to where the people live. Thus, the golf cart should be able to easily reach these locations with a single charge. Never-the-less, an associated idea is to put charging stations around town at key locations such as senior centers and parks. The idea is that the city or a private group would pay for the cost of the charging station. Each user would pay for the electricity that they use plus a "connection" fee to help pay for the operating costs. For example, $1 connection fee + 10 cents per kWHr (market rate where we live). Hopefully the local government would be reasonable about the cost. As a reminder about trying to make the transportation more sustainable, having a solar panels attached to the charging station would be a nice option. The charging stations would hopefully have connections for many types of devices from electric cars to golf carts to computers to hand held electronic devices. This should increase the station's use and shorten the payback period.