Property value impact in El Dorado Hills would be Zero.
Appraisal
models, including those cited by Mather noise complainers, forecast no
noise-induced depreciation. Our actual measured noise level is in
the range indicated by the models to represent "no significant noise".
The only areas with homes whose value is likely to depend on jet noise are new developments adjacent to Mather Airport.
Also,
the claim of $1 billion loss of property value is predicated on Mather
becoming a major cargo hub. No such expansion is planned: See the
fact check page covering this claim.
The study cited by the main local web site opposing jet freighter noise and fairly is "The Impact of Airport Noise on Residential Real Estate", by Randall Bell, MAI, published in The Appraisal Journal
in its July, 2001 issue. Randall Bell is a licensed appraiser in a firm
with offices in Laguna Beach. That area's main noise issue is due to
airline departures from John Wayne Airport in Orange County, whose
westbound departures overfly residential areas.
This as well as all other sources found to date consider NNI values less than 35 to represent "no significant noise" and to produce no impact to real estate values. For NNI greater than 35 the article summarized home depreciation in the table below.
In case of confusion by having the local anti-noise web site refer to the same article as evidence for depreciation, please read the article and the other references carefully. Those using the NNI index contain notes about the NNI 35 threshold, but these notes often are minimal: Their main subject area is higher noise levels, such as those at London Heathrow when early 707 and DC-8 turbojet (not turbofan) aircraft routinely produced Lmax levels well over 100 dB.
NNI
stands for Noise and Number Index, a measure of noise annoyance
originally developed in England in 1960/1961 to model the extent of
noise annoyance among people living near the London Heathrow airport.
This index includes terms to account for average noise levels and
for the average number of noise events per day. Values of the NNI index
below 35 are considered to represent "no significant noise" and no
consequent annoyance.
Here is how measured noise levels reported on this web site in December 2008 relate to the real estate value degredation reported in the table reproduced above:
Home quality is generally similar for El Dorado Hills and Foster City, both areas generally having medium-valued homes by the standards of their respective local real estate markets. Part of El Dorado Hills on the western side of the west ridge has homes which would be considered high-value. Median prices for both markets were obtained at a time of significant market depression due to high rates of forclosures.
This as well as all other sources found to date consider NNI values less than 35 to represent "no significant noise" and to produce no impact to real estate values. For NNI greater than 35 the article summarized home depreciation in the table below.
In case of confusion by having the local anti-noise web site refer to the same article as evidence for depreciation, please read the article and the other references carefully. Those using the NNI index contain notes about the NNI 35 threshold, but these notes often are minimal: Their main subject area is higher noise levels, such as those at London Heathrow when early 707 and DC-8 turbojet (not turbofan) aircraft routinely produced Lmax levels well over 100 dB.
Here is how measured noise levels reported on this web site in December 2008 relate to the real estate value degredation reported in the table reproduced above:
| Location | NNI | Probable percentage price depreciation | Sample observed median price, Nov. 2008 | ||
| Low- valued homes | Med.- valued homes | High- valued homes | |||
| El Dorado Hills CSD, near Pavilion, below mather ILS approach | 8.3 | 0% | 0% | 0% | ~ $550,000 |
| El Dorado Hills west ridge, below Mather ILS approach | 11.7 | 0% | 0% | 0% | |
| Foster City, below SFO approach (~ 400 arrivals per day) | 46.2 | 2.6% | 6.3% | 10.5% | ~ $850,000 |
Home quality is generally similar for El Dorado Hills and Foster City, both areas generally having medium-valued homes by the standards of their respective local real estate markets. Part of El Dorado Hills on the western side of the west ridge has homes which would be considered high-value. Median prices for both markets were obtained at a time of significant market depression due to high rates of forclosures.
What areas actually do show significant real estate depreciation due to jet noise?
Foster
City has minor noise impact according to the NNI index. This tends to
be confirmed by its complaint rate of 2.2 noise complaints per thousand
approaches in the first 7 months of 2008. A few other major U.S.
airports, such as Saint Louis, have areas where housing is only a few
hundred feet from airliners on short final, nearing the approach end of
the runway.
Better examples come from Europe, in places where housing crouds airport boundaries. Here are two examples.
Better examples come from Europe, in places where housing crouds airport boundaries. Here are two examples.
 |  |
| London Heathrow noise-sensitive area | Zurich noise-sensitive area |
Here are the areas in question for the Mather approach... (click on image for higher resolution rendition)
The white diagonal line is the approach course to Mather Runway 22L, representing the Instrument Landing System (ILS) approach.
The red dots over El Dorado Hills are the two noise measurement and approach altitude observation sites used on this web site, the nearest to Mather is about 8 miles from the eastmost limit of Mather's 60 dB CNEL noise contour. Noise outside that contour is considered inconsequential both in law and in fact, based on studies of noise annoyance in other airport areas.
Here's where it's reasonable to expect some degree of impact to property values, in the sense that some of the homes in this area would have a higher market value without aircraft noise. However, all housing in this area is new construction in the first decade of the 21st century. Initial sales price of these homes would account for the extent of jet noise from known and forecast traffic: Noise would not harm market value for this property.
The completed new development is in the unincorporated area of Sacramento County and experiences high singe-event noise levels on takeof of jet aircraft.The other developments mapped are in the City of Rancho Cordova and are in varying stages of buildout and planning. All of the housing developments depicted are recent, postdating conversion of Mather from an Air Force Base to a civilian airport.