The biggest contribution to reducing our carbon footprint is to have greatly improved the insulation of our building so it takes less energy to keep you, your pets and us comfortable. When we did the big build we went for a SIP construction. Our SIPs are essentially a sandwich of polystyrene foam as the “filling” and two sheets of OSB as the “bread”. OSB is oriented strand board made from wood scraps, glued and compressed into rigid boards. The panels are glued together with space filling foam, giving a whole building without gaps to prevent draughts. All of the space within the roof space is warm and within the building envelope, meaning the greatest amount of roof space can be formed without cold spots or worse still damp areas. Internally, we lined all of the walls and roof with double silver bubble wrap to further increase the insulation.
The roof covering doesn’t really help with insulation but does greatly influence the building carbon footprint. Being in a row of slate covered houses, a slate finish was the only option. Slates are difficult to come by in the UK, as most comes from Spain or China with huge product miles. Fortunately there are now UK produced new tiles made with recycled slate and we went for Britlock, one of them, meaning used materials have been made into new.
Doors and Windows
High value insulated double glazed windows and doors completed the new shell. These came from a local contractor Mark Smith Glazing.
The next big issue is the heating. We started with a gas boiler and an electric heater for the swimming pool but became interested in heating with biomass. For us a pellet system was the best and if you’ve ever seen wood pellet cat litter then you have seen biomass fuel too. It is made from sawdust arising from the timber industry and Scotland produced a surfeit of it much being exported to Europe. Going with biomass meant a new shed in the back garden half giving us a 6 tonne store and half housing the boiler. The pellets are blown into the store from a delivery tanker in the car park through a series of flexible tubes. In order to maximise the capacity of our store we didn’t go with the conventional sloping sides in the store but as surface device called a Pellet Mole which rovers over the surface of the pellets and sucks the pellets five times a day to fill the daily hopper on the back of the boiler. The boiler is fully automatic and maintains a 500 litre well insulated buffer tank in the boiler room. This through a pair of heavily insulated pipes heats the insulated 400 litre inside tank. This too is an innovative design, having the hot water tank inside the central heating tank which means that the hot water recovers more quickly after a draw of hot water which is there to cope with the (up to) 800 litres of warm water used in a treadmill session. The outer jacket of water in the tank provides the central heating for the building and the heat exchanger for the pool.
The back of our building faces south and was an ideal site for solar electric panels. We have a 3.75kW set up on a smart inverter which can cope with each panel producing different amounts of electricity without a temporary shaded panel dragging the rest down. It even has an internet connection and send live data to the manufacturers meaning we can log in and see how the system is doing on an instantaneous, weekly, monthly or yearly basis. The Government pay us for every kWh we generate and a little extra for feeding back into the grid. Also every kWh we make means one we don’t have to buy, so overall a worthwhile project.
The ongoing accumulation of incremental gains
The rest of our effort is focused on considering the best choice for each activity, as each change makes a marginal difference but the accumulation of lots of small things results in big savings in green footprint.
Such things are:-
Installing new LED lighting. Where we have added new space we have used LED lighting for circulation areas and every light in the new flat is LED.
Improving the fluorescent lighting. In clinical areas, we need bright and shadow free lighting and fluorescent strip lighting is still the best value here. However we have been migrating to the thinner, more efficient T5 tubes and using high frequency technology, rather than inefficient switch start (with the plug in starters) fittings.
Segregating our waste. We now sort our non clinical waste so as to maximise it recycling value. We are careful to recycle broken or redundant electrical and electronic items and batteries as they contain valuable rare elements as well as the more common metals.
The dog trike is a low carbon way of commuting.