Charles is a retired water enginer, ex Director of Sustainable Development with a consulting engineering firm. Judy is a retired social worker. After having installed solar PV in 2003, and solar thermal in 2005, we wanted to add a ‘sun room’ extension, and do other eco-retrofit improvements in 2008.
Motivation was originally strongly ecological, to save carbon emissions. Now that we have the house in use, comfort is better, and saving over 40% of energy and water costs is valuable for us as pensioners.
Detached bungalow, built 1950s, extended 1980s. The Superhomes entry describes eco-retrofit, summer 2008 [but solar PV and solar thermal were installed in 2003 and 2005 respectively]. Heated living space is 126m2 + 20m2 unheated ‘sun room’. Household is 2 retired people (occasionally 3).
Starting point for the changes was: Old gas (65% efficient) non-condensing boiler for heating (radiators) & hot water. ‘Low hanging fruit’ had already been done – cavity wall insulation, double glazing, reasonable loft insulation, foil behind + control valves on radiators.
Extra roof and loft Insulation, draught-sealing and a MVHR system, and low energy light bulbs throughout, reduced energy use by about 15%.
MVHR uses electricty for fan, but makes the house very comfortable to live in, with no moisture or condensation problems.
Renewables – biomass boiler, solar PV and solar thermal – systems generated approx 16,700 kWh in 2012.
Wood pellet boiler runs usually for 7 winter months; solar thermal does all hot water during 5 summer mnths; they work well togther.
Savings of 84% in carbon emissions and 46% in energy and water costs.
Great eveness of temperature between rooms, and absolutely no moisture and condensation problems in spite of no draughts.
Sun room, unheated, is so well insulated (big window is triple glazed) that it is useable all year; great for being a greenhouse too for our plants.
Reasuring to know that ~85% of our energy is not subject to fossil fuel price increases.
Being able to grow a lime tree in the sun room, with harvest of very tasty fresh limes; and the high comfort level in all rooms.
Rain water submersible pump installed 2008 was not very efficient; replaced with low energy membrane pump in 2011.
Solar PV was 9 years old in 2012; needed attention to one inverter.
Wood pellet boiler was 4 years old in 2012, needed DIY-fitted new ignition unit.
Our sun room is not a conservatory in the normal ‘buy a package’ sense of the word. It is orientated north-south. It has a mass concrete heat retaining floor and continuous 3/4 depth windows on south & part east side that are triple glazed. The north and (part) east wall is built to modern building regulations using cavity insulated brick + blocks. The sun room has a deep insulated peaked roof with three double glazed velux windows on the south roof slope.