Bog Roll :: stuff/house

It's Not Magic, It's Work!

16 Aug 2014

Using Less

Since we moved into our current house we have continually aimed to reduce our gas and electricity use year on year. We started with a number of behaviour changes relative to the previous owners - which saved 50% on gas an electricity on the first year. Since then we have gradually replaced old/worn out/inefficient things with modern/highest efficiency replacements/alternatives and significantly improved the insulation in the loft space and under the ground floor.

20095 00022 000233
20103 00019 000188
20112 67513 945137.4
20123 5269 606108.5
20132 3919 40297.5
20141 2953 74941.7

The 2009 and 2010 years are estimated and 2010 contains both our and the previous owners usage. 2014 contains only 61% of the year, so isn't comparable yet. I could also do with a scaling factor for the weather as some winters are radically different from others and that makes a big difference to the winter gas figure.

Even though the 2009 figure is an esitmate it's still only about two thirds the EPC survey the house came with when we bought it of E/48 - 314 kWh·m-2, and we're already loads better the best estimate of D/55 - 275 kWh·m-2.

05 Oct 2013

New Windows

When we bough the house three years ago we knew that the windows needed replacing. They were old Everest aluminium framed double glazed units. They had many problems: the metal frames conducted heat like mad and had deformed over the years, several of the units had blown and none of the glass was modern Low-E.

New windows are expensive however you look at it. I looked at quotes from Internorm and The Green Building Store for modern triple glazed units, using modern glass, spacers and cavity gas. For high performance "A" rated windows it's between £20 - 30 thousand, fully installed.

Even assuming high gas inflation of 10% (which is plausible) our house doesn't lose enough heat through the windows to break even until over 35 years and assuming 35% heat loss through the windows - which is more than it really is. Basically expensive windows will not pay for themselves on gas prices alone.

If you have the money required to buy the windows in the bank at the moment, and just sat on it, it would gradually devalue over time as bank interest is consistently less than inflation. If you factor in a 2% difference between interest and inflation against you, then overtime you lose a lot of money in a bank savings account. If you add this to the cost of domestic gas for heating then the break-even point is now at more realistic heat loss through the windows percentage and/or date.

It's still not a really strong economic argument for new triple glazed windows, but as the ones that came with the house when we bought it had failed, this summer we decided to buy UK made Green Building Store Ecoplus 3 windows. By making the windows simpler than the original ones we were able to save several thousand pounds on the quote and bring the price closer to 20k than 30k.

After our holidays they came and ripped the old windows out and put the new ones in. They look an awful lot nicer than the original ones and let in considerably more light. We're now in the process of making good the mess that was made getting the old windows out and the new ones in. This winter I think we will have gone from some of the worst windows and doors in the village to the best.

29 Jul 2013

Kettle Energy Use

Our faithful electric kettle started to die about a week ago, the automatic cutoff kept cutting off long before the water in the kettle had reached boiling point. It was at least 10 years old and was otherwise in good working order.

We had a look online to see what to replace it with. It seems almost all modern kettles available in the UK are 1.7 l capacity and have a 3 kW electric heating element with a minimum water volume of 2 cups (unspecified actual volume). Our old kettle was a mere 2 kW and would happily boil as little as 300 ml (one decent mug full of water).

We don't have PV panels on the roof so wouldn't benefit from a 1 kW kettle but even so, 3 kW to boil more water than I need for a single mug of tea seems very silly and inefficient. There are a few eco kettles that manage to boil only one cup full of water but they are few and far between...

In the end we found a 2 kW unit with a 1 l capacity and low enough minimum water boil volume. But it cost twice what the larger version from the same manufacturer cost.

While I know that tea and coffee drinking is quite a social activity in the UK, but there are plenty of households with only one person in or who drinks hot beverages. It seems that most people are probably wasting quite a lot of energy on heating/re-heating water that they probably don't need to.

27 Feb 2013

Diagnostic de performance énergétique

Looking up French figures you can convert European Energy ratings to an annual kWh·m-2:

RatingFrench kWh·m-2UK SAP
A< 5092 - 100
B50 - 9081 - 91
C91 - 15069 - 80
D151 - 23055 - 68
E231 - 33039 - 54
F331 - 45021 - 38
G> 4511 - 20

Our house basted on last year at 104 kWh·m-2 for a 1936 house is doing very well in band C and not the band E that the idiot surveyers put it in.

26 Feb 2013

Energy Performance Certificate

Last week someone in the village was asking about installing PV panels on their south facing roof. From 01 April 2013 the government will only allow the full feed in tariff if you have already fully insulated your house - it is obviously pointless generating electricity if your house leaks heat like a sieve.

I checked the EPC chart for our house that came with the HIP when we bought the house. It's quite pathetic, it reports loft insulation of 250 mm when in fact there was only 100 mm when we moved in. It does however note the old boiler with primitive controller and lack of efficient light bulbs. It then gives some bland advice and ranks the house at grade "E" with a SAP score of 48. The best the house could be is apparently grade "D" with a SAP score of 55. That corresponds to an annual energy use of 314 kWh·m-2 falling to a minimum possible of 275 kWh·m-2. Annoyingly there is no explanation of how a SAP rating relates to a energy use per unit area.

This is all utter rubbish! We changed all the old bulbs to mostly CFL, plus some LED and some halogen the day we moved in. Last autumn we put in a modern boiler and controller and started to insulated under the floors. We added 200 mm of loft insulation taking it up to a minimum of 300 mm over the whole loft with the spare in the centre to >400 mm. We have yet to replace the windows and doors (A rated) and complete the under-floor insulation.

For the first full year we were in the house we used 137 kWh·m-2 (a cold year too and with the old central heating boiler & controller), which is better than half the potential minimum energy use and last year we used only 104 kWh·m-2 (mild year plus new boiler for the last 2 cold months).

I am in favour of improving things, but if the official schemes and assessments are so rubbish how are people who don't know ever going to figure out what to do...

26 Jan 2013

Heat Loss Through Windows

This month I'm in the middle of a thermal imaging survey in the village. I potter around to people's houses in the evening and look for energy leaks. Everyone has been really nice and I hope I've been able to help them save a few quid and some CO2.

At the same time I'm looking to replace our old Everest double glazing units. Overall the glazing is sound, they are well spaced units and most of them have not blown. I'm not sure of their exact age but they are probably over 20 years old, as they are aluminium frames. So while the glazing is still sound the frames conduct heat like it's going out of fashion... We probably have some of the worst window (frames) in the village.

I've started the process of getting quotes for higher performance modern triple glazed windows with proper engineered frames that result in an overall "A rated" unit. Suffice as to say the prices are many thousands, the current highest quote for all new British made, top end windows is £25k.

If you believe the glass and glazing Federation, replacing our old windows with modern BFRC "A rated" ones and assuming 4% fuel inflation they calculate over 25 years a saving of £8k and just under 7 tonnes of CO2,

Based on my own figures, running a 12.3 MWh annual gas usage and using the same 4% inflation I calculate a similar saving if you assume that windows account for over 35% of all heat loss in the house. The house was built in 1936, so it's a bit leaky, so I'm not convinced that the windows are as much as 35% of the total loss. The loft is well insulated to about 40 cm of insulation, but the cavity walls were filled several years ago and I'm not convinced it was done that well.

If you assume more gas inflation then the savings come in quicker or require the glazing to be less of a source of heat loss. To get my money back on £25k, I would need to wait 30 years, at gas inflation of 8% and assume that withe windows contributed to 45% of all heat loss.

As much as I would like to buy British made, "A" rated windows, and assuming gas prices rise faster than general inflation, it just doesn't make economic sense to buy top of the range. Imported windows of similar quality cost considerably less and I will break even with them - eventually!

04 Mar 2011

Allotment Plot

Last year we bought our own house. It's a very nice 1930s semi and perfect for our needs in all ways but one - the garden is tiny. A few years ago I asked a local farmer if he had a small plot land he wasn't farming that we could put some trees on. Last weekend we put 5 apple and 3 plum trees into a small plot we are now renting from the farmer.

It was very hard work digging holes into chalky/flint soil, then banging in the timber supports. After that we had to push several wheel-barrow loads of manure and mulch up the lane to the plot to prepare the holes and top them out once planted in.

I'm not expecting any fruit this year, especially as they were planted a bit late, but in 5 years I'm expecting plenty of apples and plums!

We put in the following varieties:

  • Worcester Pearmain M26
  • Orleans Reinette M26
  • Egremont Russet M26
  • Cox's Orange Pippin M26
  • Ashmead's Kernel M26
  • Mirabelle de Nancy
  • Opal Plum St Julien A
  • Merryweather Damson St Julien A
  • Meeche's Prolific Quince A*

* The Quince went in the front garden not the allotment.

01 Jan 2011

Light Bulbs

Yesterday we were at our local DIY store looking for light bulbs and loft-insulation. There is a bewildering list of stuff available even in a small B&Q. Annoyingly not what we wanted. We did however get some things.

Light bulbs in the UK are annoying and getting worse:

  • Most sensible fittings use a bayonet fitting such as the BA22d/BC. In the past few years there has been an influx of cheap tat from China using the alternative Edison Screw fit system. That now means you have to deal with two incompatible socket and bulb systems.
  • There are also three kinds of bulbs in use, plain old "incandescent", "halogen" incandescent and compact fluorescent ("cfl"). Most bulbs quote their energy use in Watts and not their light output in Lumen.
    • So the newer bulbs will say something like 11 W, output 75 W. Meaning 11 W in electricity and the light out put of an old style incandescent 75 W light bulb.
    • To add to the complexity, most of the new and very popular halogen bulbs use a wide range of strange fittings and are a royal pain to find. Additionally they don't quote their light output or an equivalent to incandescent!
  • LED bulbs are also available, but they are very expensive and limited in output so hardly used yet.

At long last some things are starting to change. Old inefficient incandescent bulbs are being voluntarily phased out of use. To try and avoid confusion between the remaining bulbs, they are now at long last putting the luminosity of the bulb on the boxes, so you can at last compare them and have a better understanding of what is going on!

Lamp Type Typical Wattage Lumen Per Watt Typical Lumen Expected life (days) Cost per bulb
Incandescent 60 12-15 720-900 41.7 £30.00
Halogen 50 15-25 750-1250 125 £25.00
Compact fluorescent 11 60-80 660-880 333.3 £5.50
Fluorescent Tube (strip light) 10 80-100 800-1000 416.7 £5.00
LED 5 100-125 500-625 5 years £1.50
Life time is total running time, assuming normal usage patterns.
Cost is total running cost in electricity and bulbs over 5 years.

Modern cfl bulbs are much quicker to start then older ones, but still not as instant as incandescent (old or halogen). Some of them do claim to reach a high output level very quickly and there are clear differences between bulbs.

Modern cfl bulbs are available in a variety of colours and though I do have some in the house that are slower to start none of them have funny colours that they were prone to a decade or so ago. I've not seen oddly coloured cfl bulbs in over a decade.

Modern cfl bulbs do not flicker, cheap magnetic ballasts can cause flicker but almost all modern fluorescent lamps use electronic ballasts now - which also means they reach peak light output very quickly too.

Modern cfl bulbs are now available in a wide variety of shapes, you are not stuck with the old folded "U" shaped tube design. However the straight "U" shaped design is the cheapest and most efficient.

You can even use some cfl bulbs in dimmer systems, though they do not have the same range of light output as old incandescent bulbs and they are very expensive.

Finally if you really, really don't want use use cfl (like my father) you can now get halogen incandescent bulbs that are designed as alternatives to plain incandescent bulbs and while not as efficient as cfl or LED they still give our more light and less heat than plain incandescent bulbs.

See also:

12 Dec 2010

ECOS Paint

We spent this weekend painting the bathroom. We have painted the ceiling in white soft-sheen emulsion. The walls in "Jyll" a pale-blue matt emulsion - a glossier finish would have been better but we had the matt "in stock". The wooden panels have been painted in "Gynt" a bold blue satin gloss.

As ECOS paints are free of all volatile organic solvents the bathroom doesn't smell of anything horrible - the same can't be said of Dulux or Crown paint!

06 Nov 2010

What Were They Doing III?

The continuing energy use saga... Following my previous report we now have another bill from the utility and more data than last time. At the moment we are in rather a lot of credit with the power company - though they have at least knocked £100 off the monthly direct-debit payment - even so we'll still be a long way in credit in the spring.

EnergyAprilMay JuneJuly AugustSeptemberOctober
Our energy use as a percentage of the previous owner's.
In Summary, a 54% overall energy reduction, made up of a 77% electricity and a 28% gas reduction.

In no way is it a strict comparison, in fact the stupid gas changes are probably proof that the month to month figures are not a true picture. However the aggregate picture is probably fair, on the power companies annal figures it's an estimated 6.5 tonnes CO2 reduction on last year if we continue at our current energy use rate for the year.

13 Oct 2010

What Were They Doing II?

This spring we moved into a new house. We now have some more energy use data.

EnergyAprilMay JuneJuly AugustSeptember
Our energy use as a percentage of the previous owner's.
In Summary, a 62% overall energy reduction, made up of a 73% electricity and a 51% gas reduction.

In no way is it a strict comparison, and though I have continued to take regular meter readings they are not all used and power company does tend to average out previous years. On the power companies own figures it's an estimated 5.6 tonnes CO2 reduction on last year if we continue at our current energy use rate for the year.

26 Sep 2010

Current Cost Meter

Last Year Andy gave a fascinating talk at our LUG meeting all about connected data in the house. He is a top IBM scientist and involved in their messaging stuff, but he is also a very decent chap and has done wonders for gathering and using data around the home.

At the meeting I very nearly bought a Current Cost Meter but I didn't have any cash with me. This summer my power company offered me one for free and just before our summer holidays it arrived in the post.

The device is a E.On branded Current Cost Envi unit. E.On only talk about Windows but the official software is for Windows or Mac, however it works perfectly well out of the box in Linux with, "no software required". Using my Super Cow Powers - well actually a Perl script and the RRDtool package - we now have real-time and historic electricity usage graphs.

All I need to do now is use the data sensibly to reduce energy use around the home, saving money and reducing my carbon footprint.

15 Aug 2010

Crown "Breatheasy" Paint

Today we used up some more inherited paint, a 2.5 l tin of Crown "Breatheasy" low VOC matt emulsion paint. It will cover 35 m2 of previously painted wall, according to Crown.

First off, it stank to high-heaven, I dread to think what their normal odour paint smells off. My second surprise was that the whole 2.4 l has been consumed painting an area as of less than 20 m2 in our larder. The surface was previously painted masonry, so it may be more thirsty than a normal wall, but even so we got only about 50% expected coverage - less than expected.

In an hour or so it will be time to put another coat of paint onto the walls, with luck the second coat will cover a bit better now that the wall have been sealed with a fresh coat of paint.

07 Aug 2010

ECOS Sierra Matt Wall Paint

We just put a coat of ECOS Sierra matt wall paint onto the kitchen wall. It went on well and has dried up lovely. The kitchen now has a warm Mediterranean feel.

The gloss paint on the doors was much harder to live with. It doesn't look so nice and I found it really hard to put it on. I'll sand it down a bit and try another coat. The gloss on the window frames and skirting boards isn't as bad, again it will look better with a top coat.

ECOS isn't cheap but it's worth it for volatile organic solvent free paint system. All the walls and most of the woodwork have been painted the kitchen doesn't smell of paint and it all dried with in an hour - pretty good going!

25 Jul 2010


When I finished my first degree I spent a summer working for John Ashworth & Partners. It was a very interesting job and at the same time I learnt a lot about the paint industry and how poor most paint actually is.

One of the things they invented and I got to play with is ECOS*, their zero odour paint system. It is a 100% volatile organic free paint system. Basically it is a water based system that actually works.

The problem with ECOS is the same as the problem with Linux and a whole host of other things, it doesn't matter that you are vastly superior to the brand leader, the fact you are not brand leader make it almost impossible to sell the stuff.

Now I own my own home, I have to put my money where my mouth is and actually buy their paint to use on my own house. For the past few weeks I've been running down paint the house came with, soon I'll have to buy fresh and it's going to be UK invented, UK made, top quality stuff!

* Warning, the ECOS web site is a bit hippy and full of tree hugging nonsense, but the paint that is in the tins is brilliant stuff.