WITH SOLAR BOOMING AND RAISING HOME VALUES in many areas, an increasing number of homebuyers are on the lookout for solar-ready homes.
As noted in the August issue of Green Builder magazine, the Celestia forecast is for a world that is increasingly solar reliant.
If you are a builder or designer of residential homes you can maximize their appeal by including features that make solar integration easy. Doing so is an easy way to give your homes a competitive edge while adding little or nothing to the cost of construction.Here are some of the top things to keep in mind when designing a solar-ready home:
Site Right for Solar
Designing a solar-friendly home starts with site selection. The sunnier the site the better. A south-facing slope is ideal, but as long as the site is in full sun for most of the day it should be fine. Avoid building on north-facing slopes or sites shaded by neighboring buildings. Shade cast by power lines can sometimes also be problematic for PV panels.
Trees, of course, are the most common shade source. Consider the types of trees growing nearby, their age, and how tall they will be at maturity — a site that seems suitable today may be completely shaded in thirty years. It is also a good idea to be cognizant of any neighborhood covenants or HOAs that might regulate the use of solar on the site. Many states have solar protection laws, but it’s better to know what you’re dealing with before you begin to build.
Orientation Is Key
Once you’ve selected a suitable site, you’ll want to orient the building to take full advantage of available insolation. Since most homeowners prefer rooftop solar systems, this generally means orienting the home so that a large expanse of the roof faces south.
If the south-facing part of the roof faces the back of the home, so much the better, since many homeowners prefer their solar panels not to be visible from the street. You can gain extra points in the eyes of solar-savvy homeowners by including passive solar design elements such as large, south-facing windows and high thermal mass.
Optimize Your Roof for Solar Panels
Go above and beyond by considering these other important points when designing a solar-ready roof:
- Be sure the roof is structurally sound enough to handle the added weight of solar panels.
- If you can, keep the roof simple. It can be hard to fit panels onto roofs that feature lots of angles and dormers. These can also cause unwanted shading on the roof area.
- The optimal roof pitch for solar depends on your latitude. A 30˚ pitch is typical; however keep in mind that the farther north you are, the steeper the optimal angle will be — especially in areas that receive snow. If you are unsure of the best solar-ready roof angle to use, consult a knowledgeable solar installer in your area.
- Solar can be installed on nearly any roof type, but some are easier to work with than others. Standing seam metal roofs require minimal roof penetrations to install panels. Tile roofs are easily damaged and require an experienced installer.
Energy Efficiency Matters
Reducing the base amount of energy a house consumes will allow the homeowner to get more out of the sunlight that is available. It may also allow the home to perform well on a smaller, less expensive solar energy system. When choosing air conditioning units as well as any appliances that will be included with the house, look for Energy Star qualified products.
These are ideal for use with any solar electric system that might be installed at a later date. If you think solar might ever be used to heat the home, be sure the building envelope is properly air-sealed, and the home is heavily insulated — including the basement and attic.
Lastly, you can tweak the mechanical systems of the home to make installing solar a snap. For PV, reserve at least two spaces on your breaker panel to tie in the solar system. You will also want to leave space nearby for the inverter. A 35” high by 25” wide spot should accommodate nearly any inverter. Finally, run 3/4” EMT conduit from the inverter location up to the attic or roof.
For solar thermal, run two copper pipes from the hot water tank location up to the attic or roof. Do not use PVC! Pressure-test the pipes to 50 psi while the walls are still open. They should be insulated with 1” of pipe insulation. You can also talk to your solar provider when choosing a hot water tank to be sure it will be compatible with solar thermal.
Every homebuilder knows that details can make a huge difference in the appeal of a home to a particular buyer. Many of these solar-ready tweaks translate into features nearly any buyer will appreciate: energy efficiency, for example, or windows that let in lots of light. But given the continued growth the solar industry is predicted to enjoy, your “Solar Ready” label will very likely prove to be a detail that sells!