Almost impossible to find the gems now
It is now clear that [waterfront + mildest climate] is what defines the real estate diamonds.
It has become almost impossible to find the gems in the jungle, since hardly one realtor provides and enforces "Waterfront" as search criteria, while the gems disappear from a market where the listings continually grow in length.

Goal
The goal of this page is to list Waterfront Property (Land Only) of any type - Beachfront, Oceanfront, Lakefront - in the mildest climates for european races in the European Union.

The sum of Heating and Cooling Degree Days (HDD and CDD, base 18.5°C / 65°F ) is used to define such climates.

Mining areas
Using a exclusion threshold of 1300, these are the areas where to search for the gems:
- Madeira, Azores Islands and some coasts of some Canary Islands;
- Algarve (from Lagos to spanish border);
- Balearic Islands;
- spanish coast from the portuguese border to Nerja;
- western Corsica (south from latitude 42°) and western Sardinia.

Notes
Note that except for Morocco and Algeria, the next closest areas to Europe with a climate below 1300 HDD+CDD are much more distant: in South Africa and southern Brazil in the southern hemisphere and Southern California in the Pacific Ocean.

All data is based on the Global Summary of the Day dataset for 1994-2008 period.

More Notes

The Canary Islands are restricted to 'some coasts of some islands' because a second exclusion threshold is used, related to the basic sustainability criteria: 50% of water consumption obtained from renewable resources.

HDD + CDD for the Estoril and Cascais Riviera (west from Lisbon) is just above 1300, but there is no point including this area, since there was not any waterfront property in the market for the last decade.

Using the Global Summary of the Day dataset enables an extreme accurate computation of HDD and CDD, using daily average temperatures and daily average amplitudes.