Architectural form, orientation, and energy for residential design in the Southern Nevada region.
Creators: name: Vaca, Ludwing 
Publisher: name: University of Nevada, Las Vegas
Year: 2015

description: With the population increase, the high demand of energy from the residential sector, as well as the harsh weather conditions of the Las Vegas region, there needs to be careful consideration in the design of new homes. Energy efficiency in a single family residential building can be augmented early in the design process by careful consideration of the building form and orientation. A systematic investigation and analysis was taken to study the effects of five building forms and different orientations along the cardinal points using the software BEopt version 2.4.0.1. To connect the study to real world circumstances, a residential development in the Las Vegas region was modified using the information found in this study to see how residential developers can design these communities and their buildings with optimized orientations for potential energy savings. 
The cooling study gave the most diverse results for the different shapes analyzed, with some of the shapes outperforming others in different orientations. Even though the rectangular and square shapes have less surface areas, the L, U and courtyard shapes seemed to have benefited from self shading to reduce the cooling loads. The L and courtyard shapes in particular performed the best, with the U shape not far behind them. The square and rectangular shapes used more energy to cool the homes, specially the square shape. As an average between 3-5% more energy was spent in space conditioning in the square and rectangular shapes than the courtyard shape. Moreover, the rectangular shape showed the largest delta change and was more sensitive to an orientation change. The largest variation was as much as a 5% increase from south to south west.
The results for all of the shapes show that the greatest energy use is spent in heating the homes, as an average 3.08 to 4.05 more times than cooling, or 69.3% to 74.2%. of the total energy spent in space conditioning. The total heating results were more predictable and not as varied as the total cooling loads from the previous analysis. The smaller and more compact homes responded better and used less energy for space heating, with the square shape outperforming the other shapes in all orientations and the rectangle coming a close second. The courtyard shape behaved the opposite as it had for cooling, performing the worst of all the shapes studied.
The two shapes that performed the best for combined cooling and heating loads were the square and rectangle shapes, followed closely to the L-shape. Though the rectangular shape performed better in north and south orientations, from WSW 67.5° to NW 157.5° and from ENE 247.5° to SSE 337.5°, the square shape actually performed better than the rectangular shape along these orientations. Moreover, the L-shape was not far in performance to these two shapes, considering it had two more additional surfaces. As an average, it used 1.1% more energy than the rectangle and 1.7% more than the square. While the courtyard shape, as an average, used about 14.6% more energy than the rectangle and 15.3% more than the square shape. It is also important to note, that the square shape performed the best in all orientations, with the rectangular shape using 0.6% and the L-shape 1.7% more energy. 
If a developer would like to repeat a unit type and mass produce it for subdivision, the rectangle form actually performs the worst to orientation changes. Instead the analysis performed on this paper would recommend the use of a square plan, as it performs overall better around the different orientations.
Current energy prices in electricity and gas utility charges are affordable to homeowners. The study showed an increase of only 1% to 2% between orientations or no more than $15 in yearly costs for space conditioning. Similarly between the different shapes there was an average increase of $122 in utility costs for space conditioning, which is an increase of only $10 per month. However, a more significant finding was the annual savings that could be done on the layout of residences in larger subdivision developments that are present in the Las Vegas region. A more meaningful impact was seen by simply orienting the variety on units to the more optimal south facing direction, about nine households in Nevada could be given free electricity yearly. As the Nevada population increases and the demand for single family detached residences continues, the design and construction industry need to have a more careful examination of the layout of these communities to reduce their energy demands.