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Quiet living created by sand and vegetation

At what point do we consider a quiet home to be really 'quiet', also with regard to low-flying aircraft? The roofs of homes near Holland's Schiphol airport are 30 to 35cm thick! But in our semi-underground office, which is 35 meters from a busy highway, the 20cm layer of soil on the roof and the solid earthen wall around it guarantees total silence.

How do you create real quiet? Here are few tips about the essential earthen walls and a good roof covering. In our manual for the building your own semi-underground home, the cement foundation and the wooden structure are presented in detail. The following tips are the result of our 20 years of experience in building 'semi-underground' constructions.



1. The wooden (light, radiant!) roof structure must be slippery and finished with rounded corners and rims, and then carefully (leak-free!) covered to just under the cement rim with high quality roofing paper. Insulation can be placed between the wood and roofing paper.

2. Because this will otherwise settle by quite a few centimeters, the rim of the highest (sand/soil) wall around the new house must be stabilized by stamping and sufficient watering. It must be raised to approximately 3-5 cm above the wooden roof, allowing it to then settle even more. Make sure there are no sharp nails or stones present.

3. Spread an approximately 5 cm thick layer of straw (lightly pressed) on the roofing paper.

4. Put a layer of plastic on the roof that stretches halfway up the earthen wall. Gardening plastic of 0.15 mm thickness is good; the widest piece of plastic available in this thickness is 14 meters wide. Avoid seams or adhesive edges. Otherwise overlap with a strip of at least 1-2 meters; under and on top of the rim – and tension-free – tape the pieces together with double-sided tape.

5. Cover the plastic layer on the roof with a fresh layer of chopped straw and then, in the same way, cover this with a second plastic layer.

6. To repeat: Three plastic layers of 0.15 mm thickness together provide almost a half-millimeter sheet. Be careful when working (walk around in socks, continuously inspecting the plastic for tears). Then, spread a 10 cm layer of clean stone and pure sand on the earthen wall, and a 15 cm thick layer on the roof.

7. Spread a thin layer of mould (black soil) on the roof and the earthen wall. Again, check carefully for sharp objects!

8. The earthen layer can be planted with for example a roadside/pasture vegetation mixture, complimented by wild flower seeds. You can also plant a small tree or shrub that doesn't have taproots, such as a hazel wood. To do this, use at least 25 cm of earth and sand. After sowing the seeds, lightly press the ground.

9. Water during long dry spells.

10. Plant new plants and flowers in the following autumn. Watering is only necessary during extreme droughts that last for more than 8 weeks.