I was an energy efficiency engineer in the NHS (now retired).
The house conversion is a DIY project, it was purchased as being especially suitable for this purpose.
The project (working alone) took four years.
I believe I will get the money invested back in less than four years due to energy price increases that are inevitable in the next few years.
I have always been interested in saving energy (and money).
I have upgraded four previous houses I lived in but this is the first Solar Passive house project.
I believe everybody should be able to benefit from this technology, ie all future new houses should be built to passive house standards. It is important to publicise the fact s about what is possible, many people just don’t know.
Conspiracy theorists think it is a government plot to line the pockets of the fossil fuel companies.
The property is a 1930′s bungalow specially purchased because it was ideal for conversion to a Solar Passive house.
(Due to position and orientation.)
It is constructed with 200mm brick walls everywhere, an important heat storing feature.
It now needs no central heating system and hence no gas, oil or coal. There are no maintenance bills either.
There is a small woodburning stove that is used in Winter for two or three hours per day in cold sunless periods lasting more than a few days.
The photovoltaic array generates as much power as we use, on a good year, slightly more, so we are a net exporter of energy.
The property has recently appeared on BBC “Newsnight”, “BBC West midlands” and radio Hereford and Worcester.
(1) Massive external insulation.
(2) Form large South facing windows and small North facing windows.
(3) Insulated doors and shutters.
(4) Attention to draught proofing and ventilation.
(5) Installation of 3.88Kwp PV array.
(6) Installation of solar thermal panel (home made).
(7) Rainwater harvesting.
(8) Energy efficient lighting.
(8) Efficient layout of Domestic Hot Water system.
(9) Heat collecting conservatory.
(10) Light tube.
The benifits are financial. Plus the morally superior feeling.
Because this is a conversion of existing building to Passive Solar House standard, some compromises have had to be made. Some existing concrete floors are not insulated for example.
However I believe a new Solar Passive house could be built for no more money than a conventional one as no heating system or gas service is needed.
In the Winter period I need approximately 40Kg of dry wood which I has cost nothing because I grow my own. Cut up with electric chainsaw on sunny days (Solar power.)
Mitsubishi I-Miev electric car is charged up from solar PV (weather permitting) and has zero road tax.
As important, What didn’t work.
Attempt to build thermal (heat) store.
I now believe these can’t be made to work on a domestic scale. The reason being that by the time the heat is needed, it has leaked away. On a small device the heat can only be stored for a couple of days at most.
Also unless the store is enormous, the amount of heat stored is negligible due to the low temperature most operate at.
There are no favourite features. All are neccessary to achieve net zero energy use. The house is designed for maximum efficiency and the exterior looks no different from any other house.
There are no strange appendages, impractical features or archtect’s totems.
Electric car is charged up from PV panels weather permitting.
Updated on 09/01/2013