Sustainable Refurbishment – Towards an 80% Reduction in CO2 Emissions

by Jamie on April 6, 2010 · 2 comments

The UK’s building regulations didn’t start to consider energy consumption until the 1960s, when very basic requirements to conserve energy were placed on house builders. These requirements have slowly been tightened over the decades and the introduction of the Code for Sustainable Homes has accelerated this in recent years.

The intention is that new build homes built from 2016 will be zero carbon (although the exact definition of ‘zero carbon’ in this case is still up for grabs). The problem is that the UK’s housing stock is the oldest in the developed world, with 8.5 million properties over 60 years old and an estimated 24 million homes built up to 2016 expected to still exist in 2050.

Zero carbon new build homes are definitely needed so that new homes don’t add to emissions, but all of the carbon reductions will have to happen in homes that have already been built.

In the previous post we looked generally at a whole house approach to sustainable refurbishment. The Energy Saving Trust has recently published an interesting new publication which looks at this in more detail and points the way towards an 80% reduction in CO2 emissions in existing homes. This guide is aimed at homeowners as well as housing developers and builders and is clearly written and nicely presented.

It gives an excellent overview of the energy efficiency measures that can be implemented in the UK’s homes including the different types of wall, roof and floor insulation, improving windows and doors, increasing air tightness as well as efficient heating and hot water systems and lighting and appliances. Also covered are microgeneration, water efficiency, waste and recycling and even climate change adaptation.

If you want to get a good picture of what needs to be done to our homes, then this is a good starting point. Hopefully it will stimulate you to consider which of these measures can be applied in your home.

The Energy Saving Trust has lots of interesting technical guidance. More information can be found here.

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The Whole House Approach to Carbon Reduction

by Jamie on April 5, 2010 · 1 comment

The challenge to reduce CO2 emissions from the UK’s homes by 80% by 2050 is a tough one. The good news is that this target is very achievable but there is a lot of work ahead of us in order to see it happen and cutting emissions this far will require us to take a different approach to improving the energy efficiency of our homes to the one taken to date.

Financial support for carbon reduction measures in the home has mostly come from the Carbon Emissions Reduction Target (and before that the Energy Efficiency Commitment). Both programmes are obligations on the energy suppliers to reduce carbon emissions from UK homes by subsidising a range of energy efficiency measures.

The activity is funded by a levy on our energy bills (the energy suppliers aren’t doing this out of the kindness of their hearts), which means that they opt for the cheapest route to achieving their targets. This isn’t the most effective means of starting us on the path to an 80% reduction in CO2 emissions.

Mostly this support takes the form of piecemeal work such as discounted loft or cavity wall insulation, energy saving light bulbs (too many of them) and assorted other measures. Lots of homes have taken advantage of these offers and if you have a loft that hasn’t been topped up yet or a cavity wall that hasn’t been insulated, you should too.

But this activity only tackles one aspect of a home’s energy consumption and this tactic will not be sufficient to achieve an 80% reduction. Instead, a whole house approach is the most logical way to go about it.

A whole house approach doesn’t mean that the whole house has to be done in one go. Instead you want to consider all of the solutions that are appropriate to your home, work out the order you need to do them in to deliver the biggest carbon savings at lowest cost and then do the maximum amount possible as each opportunity to do the work arises.

These opportunities might include moving house, redecorating, roof repairs, re-pointing your walls or redoing your kitchen. It might even be something as simple as doing a spring clean and Freecycling the contents of your loft, freeing up space to add more insulation.

If you are considering doing any of this sort of general work to your home, you should be looking at improving the building’s energy performance and do as much work, to as high a possible standard (beyond building regulations) as you can afford.

While it will stretch your budget, the cost of doing that same energy efficiency work in a few years time will in many cases be considerably higher because you might have to strip back to the brickwork, put up scaffolding, do the work and then redecorate all over again. If you are going to have tradespeople on site anyway, there are savings to be had in the long run by doing that extra bit of work at the same time.

You also want to have to do each energy efficiency measure once only so you should look for the best solution for each aspect of your home. For this reason, measures that appear to be a cheap fix (insulating wallpaper springs to mind) are best avoided. While the costs are often a lot more modest than the alternatives (in this case full solid wall insulation), so are the energy savings and you might well find that in some years time you’ll need to go through the whole process again.

Financial support is moving in the direction of a whole house approach at the moment. In the next couple of years we are going to start to see the introduction of funding that pays for the more costly measures up front. You then pay this money back from the energy savings, with any outstanding balance remaining with the home, not the homeowner.

Between now and the introduction of this support, there’s lots that you can be getting on with to reduce energy consumption in the home. Work out what could be done to your home and what you can afford and then keep an eye out for those times when you’re going to be doing work anyway and take advantage of those opportunities to invest in energy efficiency.

The next post will point you to a guide that goes into more detail on this whole house approach and should stimulate some ideas.

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First Stoke Newington Draught Busting Saturday

by Jamie on April 2, 2010 · 2 comments

This weekend we had our first Draught Busting Saturday in Stoke Newington. This hands-on workshop was pioneered by Hyde Farm CAN and has been picked up by Peckham Power and Transition Belsize amongst others and we thought it was about time we gave it a go.

Draught Busting workshops are held in a local house in need of improvement. Stoke Newington resident Cath very kindly let us loose with hammers in her home and expertly facilitated the group as we got stuck in to  the job.

The session focused on fitting draught stripping around the lower half of the sash windows and around doors but we also touched on blocking up chimneys (Cath had gone for a DIY solution of a plastic bag stuffed with material), radiator panels (which are fixed behind radiators mounted on external, heat loss walls), and ensuring that loft hatches are well draught proofed to stop warm air rising up into the loft space.

Draught proofing the upper half of a sash window requires a ladder so that you can get up to the outside of the window frame (you can’t do the upper half of a window from the inside as you wouldn’t be able to open the window).

Just doing the lower half of the window will cut out a substantial amount of the air passing through and cutting out those lower level cold draughts will have a noticeable effect on your comfort. The upper half of the windows can be a project for the future – perhaps we could secure a ladder for a weekend and go round all of the houses that have done the work to the inside in one go.

Draught proofing is a very easy skill to pick up but there isn’t a great deal of practical information out there about the materials and techniques and so it can seem daunting – until you’re shown how easy it is to do, that is. The people who attended the session will now be in a position to share the knowledge with family and friends.

After the success of the first session, we’ll be looking to roll this out on a larger scale in time for the next heating season, around September and October.

If you’re interested in participating then please drop us a line. In particular we are after people living in homes in need of draught proofing who would be willing to host a session in Autumn.

We’ll also be placing a bulk purchase for draught proofing materials so as to make this measure as cheap as possible and so that it pays for itself as quickly as possible.

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Energy Efficient Lighting Pt 1 – CFLs

by Jamie on March 30, 2010 · 3 comments

The widespread roll out of compact fluorescent lamps (CFLs) has caused quite a stir to say the least – these innocuous little things have upset quite a lot of people, with some feeling the need to take drastic action.

Certain sections of the press definitely haven’t helped, spreading some pretty extraordinary stories about CFLs over the last few years; stories which have been designed to spread confusion and fear of what is a very good and safe energy efficiency technology.

People have been working under fluorescent lighting for decades and a CFL is not very different to an office fluorescent tube – it’s just been folded up on itself into a much smaller space.

That’s not to say that they’re without fault. They contain a very small but significant amount of mercury and therefore need to be handled appropriately (more on that in a future post), in some cases they can take a moment to warm up which is not what we’re used to after a century of incandescent lighting and the light that some give out is not the best.

Another problem is that a lot of unsolicited bulbs of varying quality have been distributed under the Carbon Emissions Reduction Target, with people receiving bulbs through the post with the wrong fitting, bulbs that give out a harsh light and bulbs that looked, well… pretty damned ugly.

But it definitely doesn’t have to be like this so this post is dedicated to the things to look out for when hunting for the perfect CFL.

CFLs use about a quarter of the electricity of a conventional incandescent. This is a big saving and one that means that you shouldn’t wait until an incandescent bulb blows before replacing it.

The embodied energy of a CFL (the energy used to produce it) is greater than the embodied energy of an incandescent bulb, but the efficiency savings you get from using CFLs greatly outweighs this additional energy so swap all your remaining incandescent bulbs today.

Defra has published a comprehensive life cycle assessment of ultra efficient lamps which is worth reading if you want to know more about the environmental impacts of different lighting technologies.

You can pick up very cheap (often subsidised) CFLs all over the place nowadays but I find it’s worth spending a few pounds on really good quality bulbs. On average a CFL will save a few pounds each per year and if it’s replacing a high use bulb it’ll save you a good deal more than that and over the lifetime of the bulb they will save you anywhere between £50 and £100 per lamp.

In different situations you might be looking for different qualities in your CFL. For example on an upstairs landing you might want one that warms up quickly, in the living room you might want a warmer light while in the kitchen you might want a bluer and brighter light.  As these types of bulbs last for a good 10,000 hours, it’s worth finding the right one for your needs.

The thing that many people seem to object to most is the colour of light that CFLs give out, known as the Colour Temperature.

You can buy fluorescent lamps in a range of colour temperatures from 4000K (or 4000 Kelvin, sometimes known as “cool white”) which gives a stark, blue light, to 2700K (sometimes known as “warm white”) which gives a much warmer colour very similar to incandescent bulbs. Natural daylight is very blue and has a colour temperature of about 6500K.

For most people this lower colour temperature (which confusingly gives a “warmer” colour) is what they should be seeking out.

Another measure of the quality of light which a bulb gives out is the Colour Rendering Index. This measures how faithfully the colour of  a surface appears under different light sources compared with an ideal light source.

The scale measures up to 100 and the higher the CRI the better. You can buy CFLs with a CRI of over 80.

Efficacy is a measure of how efficiently it converts electricity into light and is measured in Lumens per Watt (Lm/W). You will sometimes see CFLs with the same power consumption but different Lumen output (i.e. one is brighter) and this is an example where one lamp has a higher efficacy than the other.

The use of Watts to describe a bulb’s brightness is being phased out at the moment and you’re going to be reading a lot more about Lumens in the future (both will be displayed on packaging). It makes a lot more sense to use Lumens as this is a measure of brightness whereas Watts are a measure of power consumption.

The following table gives the brightness that incandescent lamps of different power give so you can work out what brightness a replacement CFL should be.

The “clear” column gives the brightness of incandescent bulbs made with clear glass and the “soft” column is the brightness for the frosted sort of bulb:

Power (W) “Soft” Brightness (Lm) Clear Brightness (Lm)
40 335 365
60 575 620
80 830 895
100 1075 1175

(Source: EST Lighting Specification)

In common with all lights, including incandescent bulbs, CFLs lose some brightness over their lifetime, but if you buy a good quality bulb they will give a good light output for a very long time.

A bulb’s start up time is also important for many people. CFLs switch on very quickly (less than a second) but then take a while to run up to full brightness. They can take up to a minute or so to reach their maximum brightness, but what is most important is how quickly they get up to a reasonable brightness.

If start up time is important to you then look for “fast start” bulbs that warm up quicker than regular bulbs. In some cases I find it’s nice to have a slow warm up time, especially in bedside lights so that you’re not blinded in the middle of the night.

So that introduces the technical aspects to look for. Size and shape should also be considered as some CFLs won’t fit as neatly in a lampshade as others but there is now such a huge range out there that you can find excellent bulbs for nearly every situation and the number of good quality bulbs is growing all the time.

For the record, my favourite CFLs are made by Megaman but there are a load of good ones out there. At some point I might do a post collecting together the best bulbs from each manufacturer. Feel free to post your favourites in the comments below.

In future posts we’ll look at other aspects of lighting such as halogens, what to do if you have dimmer switches and other technologies such as LEDs.

Power (W) “Soft” Equivalent Clear Equivalent
40 335 365
60 575 620
80 830 895
100 1075 1175

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Hackney Green Projects – Wildflowers & Orchards

by Jamie on March 28, 2010

I thought I’d do an occasional post highlighting some of the amazing green projects which are underway in Hackney at the moment. It’s lovely to see there are so many people out there striving to make the place that little bit more special.

First up there’s Friends Of Homerton Station who are planting wildflower meadows at Homerton Station.

The station is the first impression many visitors will get of an area and all too often they are badly neglected spaces. This project aims to transform Homerton station into a little biodiversity hotspot with a beautiful array of plants and flowers and the insects and birds which they attract.

Network Rail supports community groups wishing to improve derelict railway land (the Eastside Roots project in Bristol is just one success story).

Friends of Homerton Station are looking for people to help out, so if you live in the area drop them a line. I can’t wait to see it when the meadows are flourishing.

Also on the growing front, the London Orchard Project is coming to Hackney this year. The project works with local community groups, showing them how to plan, design and care for a community orchard. Already the project has helped plant 12 orchards in 9 boroughs in London.

The orchard will take a few years to start bearing fruit but in the meantime there are lots of mature fruit trees out there in public spaces and private gardens. The London Orchard Project is working with local groups to map the location of these trees, rejuvenate them and harvest any fruit that would otherwise go to waste.

I’m looking forward to my first taste of Hackney Scrumpy…

Feel free to post examples of other exciting green projects which are bubbling away at the moment.

http://www.friendsofhomerton.org.uk/

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UK Emissions down 10% in 2009

by Jamie on March 25, 2010

The Department for Energy and Climate Change (DECC) has released provisional data on UK CO2 emissions for 2009 along with a discussion of the results.

The numbers and are in million tonnes of carbon dioxide (MtCO2) and are broken down by source, which means that they do not allocate electricity consumption to the end user.

The figure for the residential sector is therefore just for emissions from burning fossil fuels in the home for space heating, hot water and cooking. We’ll have to wait until this time next year to see the end user emissions data (just published for 2008).

The results from the biggest sectors are quite striking to say the least:

Energy Supply: 186.2MtCO2 (-11.3%)
Business: 72.4MtCO2 (-15.3%)
Transport: 121.8MtCO2 (-6.5%)
Residential: 76.7MtCO2 (-5.0%)
Industrial Process: 11.1MtCO2 (-19.0%)
Total: 480.9MtCO2 (-9.7%)

The impact of the recession is clear to see in all areas.

Emissions from electricity generation dropped by 13% to 150.5MtCO2 as demand dropped and coal generation was replaced by nuclear generation coming back on stream after extensive downtime for maintenance.

The 5% reduction in emissions from heating our homes is good to see. This was in spite of the winter of 2008 seeing mean temperatures of 4.9°C, considerably warmer than the winter of 2009 which saw mean temperatures of 3.2°C.

The question is how do we continue this downward trajectory in emissions as the economy starts to recover?

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Track Your Carbon Footprint with The Carbon Account

by Jamie on March 24, 2010

In a post on measuring electricity consumption I wrote back in December, I briefly touched on a fantastic website called The Carbon Account and thought I’d go into a bit more detail about it because it’s really very good.

This is a dead easy to use carbon monitoring website that allows you to track your carbon emissions from gas and electricity consumption in the home along with car and flight emissions.

It displays your carbon footprint for the last year in a neat little chart to which you can add notes to flag up changes that you have made to your home or lifestyle or any times when your house was unoccupied. Unfortunately it only shows your carbon footprint for the last year (it would be great if the developers could fix this at some point).

There is even a social networking element to it so you can see how your friends’ energy consumption has changed and congratulate them on the steps they’re taking to reduce their emissions.

You don’t even need to do any conversions of your gas meter readings into kWh (something I’ll touch on soon) as it does it all for you. All you need to do is input the actual meter readings. It literally takes two minutes to take your electricity and gas readings and add them to the website.

When you first get an account, it asks you a few questions about your home and make a stab at what your annual carbon footprint might be and gives you a flat graph which doesn’t vary over the year.

As it takes a while to build up a profile of meter readings, I would suggest digging up any old bills you have lying around and adding the readings from them. Just do the “actual” or “customer” readings because the estimated readings are usually dodgy. If you don’t have your old bills, see if you can get your energy supplier to send you your past meter readings or check out their website as they may have a section where you can download your old bills.

Then take a gas and electricity meter reading on a regular basis, ideally each week, so that you can see how your energy consumption changes. You can even set up an email reminder to give you an e-nudge every week.

Bear in mind that the outside air temperature is a big driver of your heating demands so it’s quite possible that you might do some energy efficiency work and you don’t see the drop you were expecting to – it might just be that it’s been cold outside. You will still have made a saving because your energy bill would have been considerably higher than if you hadn’t done that measure.

Taking weekly readings is a good thing because it allows you to do some calculations which remove these temperature effects, another topic that I will cover in the future.

There’s plenty of information about how it works on the Carbon Account website, along with the calculation methodology. One thing to note is that if you’re getting funny results for your gas meter, it might be because it measures in 100s of cubic feet. Check out the info about this here.

So set up a Carbon Account right now and start monitoring. If you don’t know what your carbon emissions are, you won’t know how far you’ve cut them!

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SuperHomes Spring Openings

by Jamie on March 10, 2010

The Sustainable Energy Academy was formed with the aim of promoting education and action to reduce the carbon footprint of buildings and communities.

They have come up with a network of older, hard to treat homes which have had a full retrofit of energy efficiency and low carbon measures, called Old Home SuperHome. Their bold and laudable aim is “to create a network of homes that are local and publicly accessible, within 15 minutes, to nearly everyone in the country”.

This is a very good idea – we need everyone to be able to see and experience the technologies and solutions that are going to enable an 80% or more cut in CO2 emissions, and to see that people all around them are taking those steps right now.

To help this along, the Sustainable Energy Academy have organised a day of openings coming on the 28th March, when homes around the country will be open for you to visit for free. There are still places free at three homes in London and one in each of Peterchurch, Bristol and Birmingham.

The Sustainable Energy Academy promotes education and action to reduce the carbon footprint of buildings and communities.

We are currently spearheading Old Home SuperHome – a network of exemplar, old dwellings which have undergone an energy-efficiency retrofit. We aim to create a network of homes that are local and publicly accessible, within 15 minutes, to nearly everyone in the country.

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Energy Saving Trust Technical Publications

by Jamie on March 9, 2010

The Energy Saving Trust has a lot of information on the website but in conversations I’ve had with a variety of people, it can be a bit tricky to find.

The main landing pages are the consumer pages, containing very top level overviews of the measures and the savings which can be achieved.

For those of you wanting something a little more in depth, check out the Housing Professionals section. There are a load of useful tools there (including an interesting new build embodied carbon tool and a boiler sizing wizard), but of most interest is the publications database.

There are some excellent publications in there covering everything for both new build and existing homes, from insulation to microgeneration, and lots in between.

I’ll go into a bit more detail on the more useful publications soon, but in the meantime, have a browse around to see what takes your fancy.

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Curtains and Radiators

by Jamie on March 8, 2010 · 3 comments

This topic came up tonight: what do you do with a curtain hanging over a radiator? And why are radiators sited under windows anyway?

Back in the day, radiators were located under windows for a counterintuitive, but valid reason, although it has more to do with comfort than energy efficiency.

Imagine a room with single glazing and a radiator on the opposite wall. The air beside the window will be cooled and will sink as it becomes denser. At the opposite end of the room the air is warmed by the radiator and will therefore rise.

These two effects combine to circulate the air around the room, but this circulation will draw cold air from the window down into the centre of the room where you are sitting.

Stick the radiator under the window and it will warm the air beside the window, causing it to rise into the room. At the other end of the room it will descend, but it should be at a warmer, more comfortable temperature. It’s worth noting that with double glazing, this isn’t really a problem and you can locate your radiator wherever is most convenient.

So radiators are usually found under windows which have curtains which, more often than not, hang down below the top of the radiator.

Having them hang in front of the radiator is a big no no. All that lovely heat will rise up behind the curtain, right against the single glazing and will be trapped there before leaking out to warm the outside air.

Tucking them behind the radiator can also be counterproductive. Radiators work best when they have a free and unobstructed flow of air around them, helping to set up the convection* currents that circulate warm air around the room. For this reason you definitely want to avoid radiator shelves and radiator cabinets.

If you take a look at a typical radiator, you’ll see there are the thick bits through which the hot water flows, and thinner fins that transfer the heat to the air. It’s these fins that you need to keep clear and unobstructed, and tucking a curtain around them will reduce their effectiveness.

So what’s the solution? Cut the curtains so that they hang a bit above the radiator and then find some way of holding them flush against the wall. Hooks? Velcro? Elastic? Whatever works best. Just make sure that as little hot air as possible escapes behind the curtain and as much air as possible can flow around the radiators.

By holding the curtain flush against the wall, you will not only prevent warm air from rising behind the curtain, but you’ll also trap a layer of air there. Air is a fantastic insulator, as long as it is kept still, so if you can keep the air between the curtain and window  as motionless as possible, you’re on to a winner.

* radiators are really badly named – they’re convectors, not radiators; but radiators they shall be known as for ever and ever…

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