Solar envelope zoning: application to the city planning process. Los Angeles case study [report]

1980 unpublished
This grant undertook t h e study of t h e applicability of t h e solar envelope t o t h e City of Los Angeles. The concept was developed and presented by t h e University of Southern California, School of Architecture under a previous grant from SERI. An abridged version of t h e University of Southern California report is included in Section IV. The City of Los Angeles was awarded this contract by t h e Solar Energy Research Institute (SERI) t o undertake a study of solar envelope zoning in t
more » ... velope zoning in t h e City. This con.tract was a subcontract of SERI's obligations with t h e Department of Energy. A special team from three participating City Departments was formed t o carry out t h e project task. The participating Departments were City Planning, City Attorney and t h e Office of t h e Mayor. SPECIFIC CONCLUSIONS PHYSICAL PLANNING 1. Provisions of t h e Los Angeles Zoning Code will need amendment t o allow for solar access protection. 2. The envelope is less restrictive than some community plans. As t h e zoning is brought into conformance with t h e community plans t h e envelope may seem less attractive. 3. Solar envelope regulations would provide another method for determining setbacks, side yards, and bulk limitations, where these a r e included for urban design considerations. Existing regulations would not b e replaced since they a r e based on f i r e access, public health and safety considerations. 4. O t h e r innovative zoning techniques should not be overlooked. Subdivision design review, Specific Plan provisions, solar easements, and required covenants and deed restrictions could be used. These could be used alone or in conjunction with t h e solar envelope concept. Since t h e solar envelope is a type of zoning which uses other tools in concert, i t offers a g r e a t deal of flexibility and consistency. There would also b e t h e advantage t h a t t h e s a m e governing bodies would be responsible for reviewing these different zoning tools when applied t o a land parcel. THE CENTERS CONCEPT .. The planned high-density, mixed-use centers represent a special problem because of their high density. They also represent a special opportunity because of t h e applicability t o other urban a r e a s around t h e country. For various reasons dealt with in t h e report, i t is difficult t o assess t h e impact of t h e solar envelope on t h e Centers Concept. The solar envelope may be applicable for both commercial and residential a r e a s in t h e centers, outside of t h e very cores of t h e centers. In order t o apply t h e solar envelope zone in centers t h e centers will have t o b e more precisely defined. District-wide solar rules should be developed for t h e centers and could include provisions for duration of shadows, transfer of development rights and other features. A rovision for t h e transfer of development rights would involve s o m e compromise o ! solar access, but in e x t r e m e cases could b e justifiable. 3. The C e n t e r s Concept calls. for innovative development in three dimensions. This could interfere with complete application of all solar access provisions. Special exemptions could be made for t h e Pedway System, t h e Downtown People Mover and other features which might c a s t shadows not permitted by t h e solar access provisions adopted. The concept also calls for t h e utilization of air rights, wherever possible. If these were small developments they might. b e exempted from t h e solar access provisions, but where large developments were planned, they would have t o conform to t h e provisions. ADMINISTRATIVE PROBLEMS 1. Preliminary estimates of t h e number of cases t h a t t h e -Planning Department reviews in a year, lead t o a conclusion t h a t as many as 6,000.envelope proposals -would have t o .be reviewed in a twelve-month period. This number might b e drastically reduced, if certain types of land use, such as single-family, and certain cases, such as yard reviews, .were excluded. Many of those interviewed were concerned t h a t t h e envelope would increase costs in t e r m s of t i m e .and manpower. Accurate estimates a r e difficult and these remain only educated guesses. 2. Several aids should'.be developed t o assist in t h e task of administration of t h e envelope. The most useful tool would b e series of tables t o e s t i m a t e t h e dimensions and volume of t h e envelbpe. Another alternative would b e a n interactive computer program which could draw t h e envelope, given lot size and orientation. Ideally, there could even b e on-line terminals at t h e planning counter. 3. One of t h e major solar envelope use issues is t h e protection of solar access in dense urban areas. If whole site access is t o be protected then density is reduced significantly. A less stringent alternative is t o guarantee whole or partial building access and allow any open a r e a around t h e building t o be shaded. This approach forecloses access options for t h e future. The final, least stringent alternative is just t o protect rooftop access. This allows high densities, but limits solar utilization t o active systems. Professor Knowles of t h e University of Southern California approached this problem by guaranteeing whole site access in residential development and partial building access in commercial areas. This represents a convenience vs. density trade-off. The application of t h e envelope, regardless of surrounding structures (whole s i t e protection), would increase ease of application" but tend t o reduce density. The application of t h e envelope, acknowledging surrounding structures, would tend t o . do t h e reverse. Most of those interviewed rejected t h e USC.approach. 4. Several .opportunities exist f o r implementing solar access provisions. Several City departments a r e now working on a Comprehensive Community Energy Management Plan. This plan will become part of t h e general plan when completed and will include provisions for solar access. The city can also integrate solar access through t h e normal General Plan amendment procedure. Finally, t h e city is involved with a state mandated zone conformance task. This task, has as its goal zoning t h a t is consistent with t h e adopted General Plan. ALTERNATIVES 1. The Solar envelope concept is only one alternative for solar access protection. AS a zoning tool, i t ' has certain significant advantages over those alternatives t h a t a r e based on private agreements. It is uniform and could guarantee solar access by municipal. regulation. The uniformity would allow a developer t o count on his solar energy installation as a continuing energy source. 2. While city-wide application would insure consistency, t h e r e a r e many arguments for district-wide application. As mentioned elsewhere, t h e envelope is more complex t h a n existing zoning tools and, will require s o m e learning period by city personnel. Secondly, by taking a specific area, application problems can be worked on in t h e "real world". A f t e r examining t h e Wilshire Park Mile and Encino Specific Plan areas, several issues became evident. To exercise normal planning considerations, some type of envelope definition must b e made, on some of t h e parcels. These a r e needed t o predict . t h e dynamics of density, shading of surrounding structures, and ,other planning constraints. It also became evident t h a t land use, land values, and physical designs, would be altered by t h e envelope. In both of t h e case studies, t h e envelope reduced densities in comparison t o t h e existing zoning. The envelope did not appear (3) Existing building patterns in t h e a r e a plus real-estate values should be considered in determining floor a r e a ratios (FAR) for new construction. (4) Rules for generating solar zoning envelopes must be sufficiently explicit arsd sufficiently generalized t o accommodate any development proposal and t o guarantee solar access t o all existing buildings t h a t might surround any parcel. ( 5 ) Once a solar envelope has been determined f o r a specified development land parcel, t h e zoning envelope is defined, limiting f u t u r e construction height, bulk and setbacks: in effect, no building or landscaping element may extend outside t h e envelope. , < 1 -
doi:10.2172/5141598 fatcat:25lyb5rndvhova5bvdwmwgt2ui