Solar Streets And Wilderness Alleys

Transforming existing neighborhoods into sustainable habitats

One of the articles in Sustainable Habitat (IC#14)
Originally published in Autumn 1986 on page 8
Copyright (c)1986, 1997 by Context Institute

Major changes in the character of existing neighborhoods can come from surprisingly simple and cost effective retrofitting. Architect Robert Loring, who divides his time between Olympia, WA and Bethesda, MD, has developed a plan that can be applied to streets with a mix of architectural styles such as one typically finds in cities and towns, or to housing developments with a more homogeneous character. How might this be applied to areas you know?

A WELL-PLANNED COMMUNITY should provide for basic needs with uncommon ease. This article describes a simple "addition" that could be made to new or existing communities to help in meeting those needs with grace.

The central feature of this design is a solar greenhouse roof which spans between houses, sheltering every second street or alley in a chosen neighborhood. It takes advantage of new or old low- rise row houses and apartments, such as those found in the older neighborhoods of virtually all cities. Its shape can be easily adjusted to accommodate changes of height or setback in a range of new or old buildings. Thus a single greenhouse roof can be adapted to a whole world of architectural variety in apartments and town houses.

The solar streets that would be created under these roofs could be like Dutch "woonerven" or residential precinct streets, which give the right of way to people on foot while limiting vehicles to 12 mph. Compared to standard road surfaces, the street surface would be much thinner and less expensive. The street lights would double as grow- lights to lengthen tropical trees’ days through northern winter evenings. And tree skirt nets would help keep the streets clean by gently catching fruit and leaves.

The street’s mild climate would allow opening up a full-size room to be a year-round porch or balcony. Owners might dress up such spaces with pillars, hedges, trellises, wrought iron, shutters, or sliding glass. When making a solar street out of an open road or wide alley, these rooms could be added on to the buildings. The rooms would reduce the street roof’s span and cost, renew the buildings’ facades, add household living and planting space, and increase the opportunities for residents to converse with neighbors, watch children play, etc. Balcony railings slanted like venetian blinds would also allow sunlight from above but block the line of sight from below for privacy.

There would be a sunny cascade of energy uses from these greenhouses, with the sun’s energy going first to the food plants, then to natural home lighting, and finally to space heating and cooling. Gardens and buildings usually compete for space, but by sharing space in a greenhouse, they add to each other synergetically.

Yet because this design covers only every other street, it allows plenty of open space for auto roads, parking lots, private yards, and recreation areas.


Let’s look in more detail at how solar streets might serve their residents. One of our most basic needs is food. Many varieties of tropical fruit and nut trees can be grown under solar street roofs. By spanning between buildings, a tree-size greenhouse can use less material for side walls and less fuel for night-time heating than it would otherwise need. The trees can easily be watered through underground "trickle-feed" tubes. Tropical trees can be significant sources of vitamins, proteins, and pure delight to the residents. The dollar value of a street’s produce could equal or surpass that of a non-hydroponic greenhouse of the same area.

Shelter and warmth are also essentials. Two to four story low-rise buildings are generally better than high-rise buildings for home gardening, remodeling by occupants, low construction cost, and low energy needs. When building or remodeling closely spaced, low-rise buildings, adding a clear, light-weight roof over a narrow back street can be a very good way to save energy. It can work by reducing a building’s need for thermal insulation on that side, capturing solar heat in winter, and holding sun-screens to keep the buildings and street cool in summer. A greenhouse roof which spans between buildings can help heating and cooling as cost-effectively as solar greenhouses attached to individual homes do.


What else could a greenhouse give us if it were attached to a group of buildings? Two answers are community social space and low-cost transit, both of which are vital to community spirit and function. Communities’ basic needs are both social-psychological and physical-economic. We are a social species, needing the teaching of culture and skills, psychological support and play. The pleasures of a comfortable public space can bring people together like a spring day in the park. Spaces which tend to bring people together help community spirit, which in turn aids neighborly cooperation in child care, crime watch, tool and knowledge sharing, and much more. Solar streets can promote this sharing year round by weaving warm and beautiful public places throughout a community.

Solar streets can also be comfortable environments for open-top electric buses, walking, and bicycling. The latter two are respectively the simplest and most energy efficient modes of transit. The streets can also help make walking and cycling the safest modes of personal urban transit. Riders and walkers must be protected from the hazards of weather and auto crossings (where 70% of their accidents occur). This protection can be provided by the construction of very short sheltered bridges and/or tunnels above and below auto roads.

How much can good, sheltered pedestrian facilities be worth for transit? Figures from the U.S. Labor Department’s 1980 Consumer Expenditures Survey give a resounding answer. A middle-income household, switching to cars that are 10% more fuel efficient, can save $125 per year. By contrast, an urban plan which reduces the social and economic need to own a car can save that average American household over $3,000 per year. It’s a much larger savings than can be had from high-efficiency home heating, home gardening, or any other area of sustainable community technology. The environmental savings can be equally superlative, helping meet our needs for a safer, less toxic environment.

With the need for local auto travel reduced, a few households in each neighborhood might save a lot of money by casting off all of their cars. Many others could save a little cash by driving their cars less often. If, as in other well-planned communities, 20% of the households got rid of their second cars, then each neighborhood of 450 families would save over $100,000 every year. And unlike cars, the pedestrian facilities can be expected to last for 30 to 40 years. In addition, the initial construction budgets can be paid to local workers, keeping even that money in a local economy to build up the community’s wealth.


The areas outside the solar streets can have auto roads, parking lots, private yards, and school yards. Assuming the solar streets encourage people to walk or cycle more, then the open-air auto roads can increasingly be adapted to a lacework of lanes or "wilderness alleys" with outdoor gardens and orchards. The lane ecosystem is continuous from each home’s back door to orchards, lakes, and true wilderness areas surrounding the town. Backyards and wilderness alleys are agriculturally valuable. They can be psychologically valuable as well for the outdoor environments they offer residents. Roof-top gardens provide their owners with even greater privacy and solitude but not with as much earthy wildness. Every building can have an urbane cosmopolitan street-scene on the one side contrasted by a backyard/wilderness alley on the opposite side. Suburbanites desire such rich variety but rarely find it. Sustainable towns can be, like Cambridge beside the Berkshires or Adams-Morgan in the Alleghenies, a balance of nature and culture.

Imagine, if you will, starting your day with a brisk walk to work through the sparkling colors of a wilderness alley in autumn, or through solar streets, arched by fruit trees, the walls hung with vines and articulated with balconies of food, flowers and herbs. It’s not likely you’d see a week in which some balcony on your street wasn’t blooming. And in spring it could stun your senses to walk these fertile and flowery streets.

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