Eco-house

PV Battery and Solar Water Heater
The southern side of the roof is fitted with a photovoltaic cells and solar water heating system. Due to the limitation of the area, we have only PV system with 1.8 KW., This provides roughly 1/3 of electric power consumption in summer, and 1/4 Power generation is depending on the weather as shown below. (Please note that there are more fine days in winter in Tokyo.).

Year	Month
2006							07	08	09	10	11	12
								128	164	181	173	165
2007	01	02	03	04	05	06	07	08	09	10	11	12
	206	226	250	216	256	223	155	244	178	177	175	185
2008	01	02	03	04	05	06	07	08	09	10	11	12
	187	235	236	208	200	177	227	190	180	185	168	202
2009	01	02	03	04	05	06	07	08	09	10	11	12
	195	178	223	252	212	171	178	200	185	188	157	187
2010	01	02	03	04	05	06	07	08	09	10	11	12
	235	155	197	196	236	216	215	250	195	140	189	201
2011	01	02	03	04	05	06	07	08	09	10	11	12
	247	192	252	246	201	174	218	202	208	195	180	192
2012	01	02	03	04	05	06	07	08	09	10	11	12
	205	188	198	212	237	185	218	253	147	0	79	180
2013	01	02	03	04	05	06	07	08	09	10	11	12
	233	207	237	231	270	183	217	240	201	155	196	196
2014	01	02	03	04	05	06	07	08	09	10	11	12

Natural Ventilation
The northern part of the roof has 4 roof-top windows, and natural ventilation drastically reduces the need of air conditioning in summer.

The most unique system in our house is probably the rain water harvsting system shown in this photographe. All rain water from the roof (50 m2) comes to this 1 m3 tank, and water is used for toilet flushing.

Thanks to the new toilet sytem which uses only 6 litters per flush, this tank will be able to supply water for several days, again very much depending on weather. (We do not have water cleansing system -- which is costly -- and thus water is used only for flushing, but it was not easy to find such a toilet which uses two sources of water for flushing and washing. For your information, without water cleansing system, bath water can not be used even for toilet flushing. In our house, a good portion of bath water is used for laundry washing, by the way.)

Another difficulty is its designing - there are many huge scale water harvesting system, and tiny ones which uses small tanks., but nothing in between! Thus this system is a result of my own ammatueur desgning and rather lengthy discussions with the architect.

Comments will be welcomed at;

Though only after 27 years, our old house became really old and damaged - such as by termites. We finally chose to demolish it and completely construct a house, before we become too old.

We asked the architect to make a house which may last for a hundred years. Other requests included; (i) the living room should be made largest, (ii) an utility shaft should be made so as to accommodate any future technological developments, such as in-house computer communication system, (iii) a house elevator should be equipped so that old people, such as ourselves, can comfortably live, and so forth.

All these requests led to a ferroconcrete house - thus it appears somewhat distinct in our vicinity, but I hope that it will become somewhat harmonious in not so remote a future. The constructor granteed its life of sixty years, though water facilities will require refurbishing after 20 years.
Designed by: Studio CY.
　http://www.studiocy.com/
Construced by: Sekiguchi Koumuten
http://www.sekiguchikoumuten.com/index.html

Future task?
Electric floor warming system (chosen because of its long life, compared with water heating system) is very comfortable, though its electricity consumption is significant. We have to consider expanding PV system, though the physical space is very limited..