It’s been two weeks since my last post. This reveals one of my biggest barriers to change is TIME. Particularly to research, evaluate, decide and implement – let alone blog. It’s not that I’ve been idle – committing publicly to blog is proving a big motivator to at least do something every week which looks at my energy efficiency. So what progress have I made?
Last weekend (25th Nov) I visited my local DIY store to start resolving the tension between using the loft as a store, and insulating it to keep in heat. It’s quite a big space – with bits of junk from the previous occupants and some of our “loft possessions” (old toys of sentimental value, cartons etc). In preparation for some building works, we need to board it out for storage – whilst minimising the current heat loss (as flagged in our home buyers survey).
The roof is tiled and battened but no roof lining – hence everything in it gets quite dirty. In most places, the loft is insulated to about 100mm with vermiculite – a mineral granule. It’s not evenly spread and there are some gaps – notably above our bedroom, around old water tanks and halogen lights recessed in the ceilings below.
We’ve had some quotes to convert the loft into a “clean”/insulated storage room with velux windows (£7k), into a living space (£35k) and my energy supplier offered to insulate to current buildings regs for free if we emptied it but this would leave us without storage space so we decided against. The professional advice was to lay on top of the vermiculite – rather than remove it. I can see that the cost of removal could be quite high but I do wonder about its performance as an insulating material and it is filthy. I will need to return to the question of its performance in a future blog.
We can’t make a decision on any large items of expenditure until we know how much the proposed house extension will cost. So I am faced with either wasting lots of heat this winter, or finding an optimum DIY solution. Having spent some time as an energy manager insulating lofts with fibreglass – I learnt the hard-way about the challenges of getting the stuff up the ladders, how fibreglass dust penetrates overalls and every part of your body, and the meaning of “housemaids knee”. I swore never again …..
So on to the DIY store last weekend, I was faced with a puzzling choice of loft insulating products of varying materials, thickness, width and length and no easy way to make a cost/payback calculation. I decided to just plump for the thickest and to start with three rolls (which is all i can fit in the car) to see how far it goes. However, all the stock was wet, so getting frustrated I left empty-handed deciding more research was needed. I did pick up some loft boards so I could start experimenting with boarding out. It seems I have two choices: board, insulate and store around the insulation; insulate, and use props for the boarding so it sits clear of the insulation; line the roof itself (and then waste energy heating the loft space. More research, calculations and decisions needed.
While at the DIY store, I also purchased the lamps I needed to replace the remaining inefficient tungsten filament lamps. Replacing 5x40W lamps with 9W, reducing my lighting load by approximately 150W at a purchase price of £17. On fitting them, I started thinking about the payback but then realised I had no idea about our energy costs/bills (my wife took over paying the household bills many years ago as I have an aversion to posting letters and so we kept making late payments). I was mildly surprised to find electricity now costs 13p/KWh (I was thinking more in the region of 7p/KWh!). This means that when I have avoided 131KWh, (1700p/(13p/KWh)) the cost of the lamps will have been paid back from the electricity savings. And if I am saving 150W in energy whenever the lights are switched on, they will pay themselves back after 873 hours use (131,000/150W), which could be in under a year if I use them for an average of 2.4 hours a day (873/365). As they should last for 10,000 hours, over their lifetime they should save me at least £178 (assuming electricity costs don’t fall!). So an excellent return on investment.
Doing this quick sum spurred me on to establish our energy use and costs so I could better evaluate the payback on the investment and impact of changes introduced. Despite the Prime Minister’s recent announcement about new regulations in this area, I was genuinely surprised by the complexity of the tariffs I am on (why would any energy company put a householder on such a thing?). But I was more staggered to discover that over the last two weeks, our energy consumption is costing an average of about £10 day! Or £140 since my last blog entry!
At this expense, I decided the u value and payback calculations would wait. This weekend I made a “distress” purchase of 11 rolls of 150mm space blanket loft insulation at a cost of £110. They were chosen for their ease of handling as I couldn’t face the prospect of humping the bigger roles up the ladder, nor the hassle of cutting the insulation and generating all dust and itch. I spent saturday afternoon laying the space blanket in my loft – double layered (300mm) where there was previously nothing and single layers on top of the 100 mm of vermiculite. I reckon I’ve covered about 1/4 of the area so far. I’ve started in areas I am unlikely to use for storage and so yet to resolve the storage vs insulation dilemma – that’s for another day. After one night it’s hard to tell whether its made any difference to the levels of comfort in the house but at current running costs I am keeping a close eye on the gas meter – and I have turned the new thermostat down by 1.5 degC, so now at a maximum of 19degC. For me good energy management is about achieving cost effective levels of comfort – so we’ll have to how see this lower temperature suits the family.
In the weeks ahead I’ll be pressing ahead with insulating the loft and doing some more analysis of our energy use and potential savings. So whilst progress to date suggests I’m beginning to see the light, I sense I’ve a long way to go on this trip.