U-values might seem a pretty dull subject; however it is absolutely key that you understand them so that you can insulate your home with the most appropriate material. You can learn more about what a U-value is by clicking here.
The U-value signifies the heat lost through a given thickness of a particular material. You don’t really need to understand the mechanics of how it is calculated; instead it is useful to be able to compare different substances by their U-values.
The best insulating materials have a U-value of close to zero – the lower the better. Building regulations currently stipulate that for a new building, the elements must have maximum U-values as follows:
Wall – 0.3 W/m2k
Roof – 0.15 W/m2k
Windows – 1.6 W/m2k
So in each section below we are going to examine each of the different elements and their typical U-values, we will then show you how to achieve the best possible U-values as stipulated in the building regulations (Part L).
Solid walls were the norm in most properties built prior to the 1930s – unfortunately at this time energy efficiency wasn’t really on the radar, since fuel was very cheap. However, nowadays trying to keep this sort of home warm is very costly, so insulating them can considerably lower the heating bill.
An uninsulated solid brick wall with a thickness of 225mm value will have a U-value of 2.70 W/m2k
To insulate a solid wall you can either insulate internally or externally.
100mm of EPS insulation located internally or externally should bring the U-value of the wall down to 0.29 W/m2k in line with building regulations (in this example we have use EWI-PRO 100mm graphite EPS with thermal conductivity λ=0.032W/mk)
To achieve this with rockwool insulation you will need to add about 110mm to either the inside or outside wall (in this example we have use rockwool 100mm with thermal conductivity λ=0.036W/mk) – obviously if this is done externally you will need to attach it firmly to the wall and it will need to be rendered. If you want to do this internally it is going to steal a large area of floor space.
ThermaLine Plus is internal wall insulation (often referred to as dry-lining) attached to plasterboard and if you opt for the 40mm thick ThermaLine Plus you should achieve a U-value of about 0.65 W/m2k. This isn’t bad, but if you need to adhere to building regulations (i.e. it is a new extension for example) you are going to have to opt for something else.
U-values of CAVITY WALLS
Cavity walls became the norm in the 1930s. However until 1995, we assume that they were built but left unfilled (with insulation).
Unfilled cavity walls
Unfilled cavity wall (built prior to 1900) will have a U-value of 2.0 W/m2k
Unfilled cavity wall (built 1900 – 1975) will have a U-value of 1.6 W/m2k
Unfilled cavity wall (built 1976 – 1982) will have a U-value of 1.0 W/m2k
Unfilled cavity wall (built 1983 – 1995) will have a U-value of 0.6 W/m2k
Filled cavity walls – assumed post-1996
All cavity walls built after 1996 are assumed to have filled cavities as part of more regimented building regulations.
Filled cavity wall (built 1996 – 2002) will have a U-value of 0.45 W/m2k
Filled cavity wall (built 2003 – 2006) will have a U-value of 0.35 W/m2k
Filled cavity wall (built 2006 – 2010) will have a U-value of 0.3 W/m2k
Filled cavity wall (built 2010 +) will have a U-value of 0.2 W/m2k
Mechanisms for improving your cavity wall U-rating
For a new build cavity wall to achieve a U-value of 0.2 W/m2k you would need to install 150mm of wool but this obviously means extremely thick walls – but this is the cheapest option available to builders.
Using Celotex to fill the cavities is more expensive, but you will only need to use 100mm celotex to achieve a U-value of 0.2 W/m2k . The only thing to bear in mind here is that you still need to keep a residual cavity on the outside – but this means the cavity can be marginally thinner.
The maximum U-value you can achieve by retrofitting cavity wall insulation in any property older that 1975 is 0.5 W/m2k since you are limited by the thickness of the cavity. In this instance to achieve a U-value of less than 0.2 W/m2k, you need to apply either internal or external wall insulation too, although you will only need to apply 50mm of celotex either internally or externally to achieve this.
If you retrofit insulation in cavity walls built between 1970 and 1995, you should achieve a U-rating of 0.5 W/m2k.
Any cavity wall after that date should already have cavity wall insulation as part of building regulations – the U-values of these types of walls can be seen above in the Filled Cavity Walls section.
Energy Bill Breakdown – The Different components that make up your Energy Bill
November 12, 2013
Wholesale Energy costs
So, starting with the main component of your energy bill; the wholesale energy cost is the price of electricity and gas that energy retailers (British Gas, E.ON, Npower, etc) buy from the energy market. This makes up by far the biggest element of the energy bill – about 48% averaged across the big six energy companies, which on a bill of £1300 a year comes to about £620.
The energy companies have to secure the energy ahead of actually providing it to customers, and this is done by buying it well in advance (sometimes as much as two years) to ensure that supply is not disrupted.
All of the Big Six energy retailers: EDF, E.ON, British Gas, Scottish Power, Npower, SSE, also have generation businesses, which means they have some generating (electricity) and extraction (natural gas) capacity. However this generating and extraction capacity doesn’t unfortunately stop them from having to purchase additional energy to satisfy the demand from customers.
So although they blame the increases in wholesale prices as the reason for increasing the price of the customer’s bill, in theory they are paying themselves twice – increasing the profits of their generation and extraction businesses (which also part of the wholesale price) and then passing on any increases in the market price to homes and businesses. So their increased cost effectively turns into increased revenue twice over. It’s no surprise that the generation and extraction businesses are the most profitable parts of their business portfolios but are ‘glossed over’ and poorly understood by the press and politicians.
The companies say there is strict separation between the different parts of the business – the retail side (selling to you and me) and the generation side (sourcing the energy); and they also tell us they don’t come together and collude on price rises, but when you begin to understand how they operate you begin to wonder what they announce publicly actually stacks up!
One final point is that electricity is generated all over the UK and demand for electricity doesn’t always match the demand. Therefore there is a need to move the electricity around the distribution network to ensure customers can get the electricity when it is needed. The National grid carries out this job and they recover their costs from suppliers through this ‘wholesale energy cost’ element of the bill – this is known as the Balancing Services Use of System.
The Energy Delivery Network
Transmission and distribution is the second largest component of your energy bill. This is the price paid by the energy suppliers to the companies that operate the energy distribution networks. This makes up about 24% of your energy bill and the price paid is determined by OFGEM (the energy regulation body) in conjunction with the energy distribution companies (like National Grid, Scotia Gas Networks, UK Power Networks, etc).
These prices are rising since investment is also increasing as the old network has to be upgraded to ensure that the distribution infrastructure can cope with increases in demand and continue to deliver an uninterrupted energy supply to our homes and businesses.
For example old gas pipework is being replaced by new more robust materials, which means roads need to be dug up and new infrastructure put in place. Also a new power station or wind farm will require new cabling to get the electricity from where it is produced to where it is needed, and this is what is responsible for this component of the bill going up.
Social & Environmental Costs
Social and Environmental costs make up just under 10% of your energy bill, so on an average bill of £1,300, you are paying about £130 towards this element. Despite only being a tiny portion of your bill relative to the other components, this component has been the one that has created the most media attention since this is the one the Government have a real say in.
The background to this component is that the Government have now made it a legal requirement for the energy companies to provide help to vulnerable members of society to ensure they have access to heat and electricity and to try and make this more affordable to them. There are numerous schemes running that the Government enforces to help achieve this and we have detailed a few of them below.
These schemes target in particular elderly customers, customers with disabilities and low-income families that require an extra bit of help. The first example is the Winter Fuel Payment, which provides a tax-free payment of between £100- £300 to any homeowner who was born prior to 5th January 1952. This can also be topped up by an additional £25 Cold Weather Payment for those particularly cold winter weeks.
Another scheme that is in place to try and tackle the root causes of heating and insulation problems is the ECO or the Energy Company Obligation. You can read more about this scheme her but in a nutshell this helps drive energy efficiency among this same group of vulnerable members of society, where if it was left to the market, would priced out and excluded.
Measures available through ECO include new boilers, cavity and loft insulation and solid wall insulation, have click here to see if you can take advantage of this.
So as customers we have to decide where our priorities lie and whether we want to help continue protecting the most vulnerable. As a nation we have always done this, and I expect we will continue to do so! Whether we do this through energy bills or general taxation is another argument altogether.
Finally, the Government also have put in place policies in place to help the UK adhere to its legally binding carbon reduction program. This includes the subsidies that are paid when wind farms are built or solar panels are put on your roof. Despite a few media outlets (see the Telegraph for example!) being incredibly critical of this kind of investment – these renewable technologies will ensure that the amount of energy we need to import from places like Qatar or Norway is massively reduced, which gives us a bit of energy independence and therefore protects us from price volatility but this obviously a longer term view!
Tax
This is simply tax paid either as VAT or corporation tax – and is roughly 5%.
Operating costs
Most big companies have overheads to keep the business running, like having to pay wages. If you think that the energy companies are providing a service to many millions of customers unfortunately there is not much they can do here to pass on any savings to us! Even if top management of the biggest salaries were to be paid less, this would be a drop in the ocean sadly. The operating costs represent about 10% of the energy bill you pay.
Profit
All the energy companies claim they are making a fair profit – which is roughly 5% across the board. They claim that this kind of profit is broadly in line with supermarkets, another of life’s necessities and since they are all publicly listed, they pay a dividend that helps boost pension funds. They also claim that they are investing in new power plants to replace ageing infrastructure, but to be honest I am yet to see materialise on a grand scale, but that may just be me being cynical!
Conclusion
So there you have it – hopefully everything you need to know about how energy bills are made up. I hope this gives you enough information to reach your own conclusion whether you feel the 10% annual increases are justified. It seems to me that although wholesale costs do go up, the energy companies have not come clean on the vast profits their businesses bring in. It is only when we have full transparency that we will see the tide of trust begin to turn.
To see a pie chart showing the energy bill breakdown please click here
To read some more of our ‘bigger picture blogs – click here – a great read over lunch!
Radiators – your one stop guide!
October 22, 2013
We get tons of questions from our customers regarding radiators: when to change them, when to flush them, how to bleed them and so forth – so here we have produced a one stop guide to radiators and all the important things you need to know.
Bleeding your radiators
What is it and why do you need to do it?
Bleeding is where you vent trapped air from the radiator, which can build up over time and prevent your radiators from working correctly. Small amounts of air enter the central heating system every time fresh mains water flows through the boiler/heating system. This air collects at the top of the radiators, preventing the top part of the radiator filling with warm water and therefore reducing its heating capability.
It is important to bleed your radiators on a regular basis, since releasing this trapped air can dramatically improve the efficiency of your central heating. It is a simple job that you can do yourself with a bit of knowhow, however if you have any problems or you are unsure how to proceed, it is worth getting a plumber to do this for you.
How do you know if your radiator needs bleeding?
The best way to check is to turn your heating on and wait for the radiators to warm up. If there are any cool spots, especially near the top of the radiator, you may need to bleed it. If the radiator doesn’t warm up at all, then potentially it is completely full of air and so this will need to be released before it can be used to heat rooms.
How do I bleed my radiator?
Firstly ensure your heating is off – you don’t want to burn yourself with hot water!
You will then need a radiator bleeding key, or a flat headed screwdriver for more modern systems. At the top of the radiator at one end you will find a valve where you can put the key or screwdriver. Make sure you have a cloth ready to catch any drips!
Then slowly turn the valve anti-clockwise. You should start to hear gas escaping with a hissing sound. Eventually the gas will all be gone and liquid will start to escape. You then need to close the valve as quickly as possible to stop too much water escaping and making a mess.
The last step after bleeding all your radiators with cold spots is to check the pressure of the system. If you have bled a lot of gas, the pressure in the system may be low and in this instance you will need to top it up using the ‘filling loop’, which is a little lever on your boiler.
The final check is to turn your heating back on and just confirm that the cold spots have disappeared.
Flushing your radiators is a job carried out by professionals and involves completely cleaning them out and gets rid of any sludge that has built up over the years. It is definitely worth doing and you may find the improved warmth of your rooms means you won’t want to change your system after all.
It is a relatively more tricky procedure, and must be done by an expert. Typically this will cost a few hundred pounds. You should be aware that some older radiators could show up a leak and you’d a new radiator, but flushing really is worthwhile as your heating system should be a lot more efficient as a result.
It is also a good time to get a cleaning system like magnaclean (a magnetic filter), which helps to keep the radiators crud free in future, although this will usually be done when installing a new boiler anyway.
We often get asked when a customer is considering a new boiler – should we also change our radiators? There are several things to consider with this and it is not a straightforward yes or no answer, but some key things you should remember are:
After flushing your old radiators when installing the new system, there is a small chance you will get leaks, so you should be aware that you may need to install replacement radiators at this point anyway.
If your old radiators are quite small, they will need to be hotter to heat the room to your preferred temperature, which means the boiler is working harder. Larger radiators are more efficient as they can run at a lower temperature and still heat the room sufficiently.
Some older radiators may not be able to handle the output from your new boiler, especially if you are getting a combi or a larger boiler than you had previously. Your installer should be able to help you with this.
New radiators are often not included in any quote you get, so be aware that you are going to be paying more if you go for new ones!
How much do new radiators cost?
Typically a new radiator will cost less than £100 (this will depend on the size) and you will have to pay for the installation as well. But remember, it is important to get the right size for the room – don’t just assume that the radiators you have already are the right size and replace them with similar.
What type of radiators should I install?
Firstly you need to decide which type of radiator you are going for.
The single and double panel radiators (which can be seen below) are the older style – and nowadays if you go into a DIY store you are not going to be able to buy this type of radiator.
It may well be worth replacing this type of radiator instead of going through the costly process of flushing it out and if you do decide to do this, you will probably get away with using a smaller convector radiator because the through out more heat.
There are three main types of convector radiator (which you can see below):
Single Panel Convector radiators
Double Panel Convertor radiators
Double Panel Double Convector radiators
The panel refers to the long metal tanks that run parallel to the wall – it is these that fill with the hot water from your central heating systems and emit heat around the room. The longer the panel, the larger the heat emitting surface area, so bigger radiators will emit more heat, but also remember that a double panel radiator will emit more heat than a single panel radiator of the same length.
The convector fins (the zig-zagging metal strips) are welded to the panels and these are used to increase the surface area of the radiator so it emits more heat in a room. As mentioned previously, if you are replacing an older radiator without the convector fins, it is possible to install a much smaller convector radiator that will produce the same amount of heat.
The final thing to consider when buying a new radiator is the style at the top. Round top radiators allow you to see the convector fins, while compact radiators have a grill across the top of the panels that obscures the view of the convector panels. The performance of the two types of panel is pretty much identical, so this comes down to the finish you prefer!
Before you guy out and buy the radiator, you need to calculate the heating requirements of the room to ensure you buy the correct radiator size.
Sizing your radiator
The heat requirement of individual rooms is absolutely key to choosing the correct size radiator. For example, If you have a huge room with lots of external solid brick wall (notoriously bad at retaining heat) and you have a small single panel convector radiator fitted, it is likely the room is going to still be very cold, so you are going to need to supplement the heat.
There are software tools available that let you work out the exact heat demand of the room in question. These take into account the wall type, insulation present, the floor type, size of the room, amount of external wall and the intended use for the room.
Once you have your heat demand – typically several kilowatts or more – you can then use an equation like the one below to determine the length of the radiator required (this is based on a 50cm high radiator:
Length = Heat Demand (Watts) / (X*62)
Where X is a factor (0.09 for single panel radiators with no convector, 0.13 for single panel convector, 0.19 for double panel convector and 0.24 for double panel double convectors).
This equates to a difference of around 50% between the single convectors and double convectors, so it really does make a big difference.
With modern boilers, it is always best to design for a slightly larger radiator than you think is necessary – apart from the initial extra cost, there are not really any additional costs further along the line, since you can use thermostatic radiator valves to control the temperature of the individual radiator.d
The British standard is to place radiators on external walls under windows where possible. The external wall is easier to mount and these are usually the coldest areas of the room, so it will help to offset that and create a more evenly warmed room. On the downside, curtains above the window may shield the radiator, and heat will be lost through the exterior walls and windows. Installing a radiator shelf above the radiator, and using reflective materials such as Radflek can really help reduce this heat loss. Even better, GreenAge readers can get an exclusive 20% discount using offer code TGA20.
You might also wish to install a radiator fan to ensure the hot air gets evenly dispersed through the room (meaning the heat is felt more effectively so you can turn down the heating).
Radiator cabinets and furniture
Although they may hide the radiator from view, radiator cabinets can seriously reduce the heat output of the radiator. If you are planning to hide the radiator away like this, you will have to get bigger radiators. Likewise, if you have furniture directly in front of your radiators, it will absorb the heat produced, therefore installing a radiator fan will help redirect the heat around the room helping it to warm up quicker.
Which radiators are most efficient and are radiator boosters worth it?
All radiators effectively have the same efficiency – they give off the heat depending on how hot the water is being pumped into them. As we have mentioned however, the more panels and convector fins the radiator has, the more heat it will give off. All this means is that you can get away with a smaller radiator for the room than you would have with a single radiator however – they are all equally efficient (i.e. same cost per unit of heat).
The type of metal the radiator is made out of will determine how quickly it heats up – so an aluminium radiator will heat up a lot quicker than steel. This should not be an issue if you have a thermostat, as it will keep the room at a constant temperature.
Devices like radiator boosters and other fan assisted devices for radiators can help heat the room up more quickly so should be worth considering.
Free ways to save energy in your home
October 15, 2013
Free ways to save energy in your home – Nicks Energy Saving Tips!
Over the next six weeks I am going to share an energy saving guide with you each fortnight. This content will combine some of our favourite energy efficiency tips from TheGreenAge readers and ones that we think will make the biggest difference in your home to lower your energy bills. With the big energy suppliers now announcing their seasonal energy price increases – now is the perfect time to fightback against these spiralling costs.
And better still – not many things in life are free, but I am pleased to say that if you take on board the tips explored in our first guide it will not cost you a penny. Carrying on the thrifty theme, our second guide will explore measures you can undertake for under £100 and finally if your pocket can stretch a little further, the last guide shows you how to make some smart energy efficiency improvements that will have the biggest impact on your utility bills.
If you have any thoughts on our recommendations or have tips of your own to share – please comment at the bottom of this blog.
You may think that in order to become energy efficient and help the environment requires high upfront capital costs; however if you read on, the 5 tips in this guide actually demonstrate you can do pretty simple things that make a big difference and all for free. There are savings to be made everywhere in the home if you know where to look – so follow our pointers below and see how much you can save on your energy bills!
Check your heating controls
Turning your thermostat down by just 1°C can save you as much as £60 per year on your heating bill. The reason? Your boiler does not really need to work as hard when it comes to heating the home and to be completely honest – turning it down 1 degree shouldn’t really be noticeable.
A lot of people also have thermostatic valves on radiators, so if you have them – use them! If you have rooms in your home that don’t require heating, turn the valve down to zero (or at least down very low). This means the not wasting heat on unused rooms, which will also save you on your energy bills.
Finally – it is more than likely you will have a programmer with your boiler – make sure that you have this on in the most efficient manner. For example if your house is really well insulated and you have a fairly new boiler, leaving your timer on 24/7 and using the thermostat to determine the temperature of the home is the best way to go.
Conversely if you have an older house with solid walls that gets cold very quickly your best bet is to use the timer so the house gets warm twice a day – as you wake up and when you get home from work / school.
Unplug appliances when they are not in use
This may come as a surprise, but when appliances are left in standby mode they actually still use a significant amount of energy – so try to get in the habit of turning them off at the plug when you are not using them. If you have an entertainment system, plug it into a strip adapter so you only need turn one plug off and it will cut power to everything.
Also once items like phones and cameras are fully charged – remove the plug from socket completely. If you manage to start unplugging everything religiously the savings on your electricity bill will become noticeable very quickly.
Use your oven to heat your home
I’m not talking about switching the heating off and solely relying on your oven to heat your home here! However if you do choose to cook with your oven (remember a microwave is quicker and therefore cheaper) leave the oven door open when you are done.
This will help heat the house so you don’t need your boiler and radiators to work as hard – but obviously remember to turn the oven off!!
It costs more and it shrinks your clothes…why wash above 30°C
As much as 90% of the energy used by a washing machine is spent on heating the water. As you can imagine the savings that are there to be made are vast, especially if you lower your wash temperature down to 30°C. Most modern detergents are designed to operate at these lower temperatures – so follow the guidelines!
In addition if you only want to wash a half load – see if your washing machine has an eco function or a half load function. This means less water will need to be heated to get your clothes clean – so big energy savings!
Avoid baths (+ lengthy showers!)
A full bath will need about 80 litres of water to fill it, while a normal 5 minute shower will need about 35 litres. Obviously the water needs to be heated (normally with your gas boiler) – therefore the less hot water you need to produce the better.
A power shower will use about 60 litres every five minutes – so do try and keep these short!
So there you have it – 5 ways to save energy in the home that don’t cost you a penny. Come back in a couple of weeks to see our next guide!
Thermal liner – a cheaper way to insulate walls?
August 20, 2013
Options to insulate the walls of your home
Up to 35% of heat in the home is lost through the walls, therefore insulating them will massively lower your energy bills.
If your home was built after 1935, the chances are you have cavity walls; these are insulated very easily by injecting them with cavity wall insulation.
Several holes are drilled in the outside of the wall, and insulating beads or wool insulation are then injected into the cavity between the two skins of brick.
If you live in an older house or you know that you have solid walls (there are some exceptions to the post- 1935 rule), the insulation process is a little bit trickier.
Basically, in this instance you need to either insulate the walls externally or internally.
Insulating internal solid walls causes a lot of disruption in the home since you need to move radiators and furniture – but probably the major reason some people decide it is not for them is because it steals room space.
External wall insulation is often the preferred insulation method on solid wall properties. You can have a plain smooth finish (any colour) or brick slips.
Both external and internal wall insulation need to be at least 100mm thick, otherwise they really aren’t going to greatly improve the energy efficiency. Making your wall 100mm thicker on the inside obviously will make the room significantly smaller, especially if you need to insulate more than one wall. Hence, you might want to consider insulating using thermal liner (sometimes referred to as thermal wallpaper) as an alternative solution.
What is Thermal Liner?
Thermal liner is basically a thin material that is used to help maintain heat in a room. It is made from wood fibres interwoven with durable textile fibres. This gives you is a very strong, flexible material that when attached to the walls is said to increase the energy efficiency of the room in question.
Does Thermal Liner increase the energy efficiency of walls?
I used the Wallrock KV600 Thermal Liner in my home but I think I need to set the scene a little. I have a pre-1900 maisonette situated in South London. It is near a fairly busy road, so buses and lorries driving by have actually caused quite a few cosmetic cracks in the ageing plasterboard of one of the bedrooms. In addition, this room genuinely gets freezing in winter, but the room isn’t massive so I was looking at keeping it warm without compromising on space. Thermal liner is definitely a compromise between solid wall insulation and loss of space, but it can be the best option for homes like mine, where space and energy use are at a premium.
Installing the Thermal Liner
Firstly the thermal liner is very easy to attach to the walls. Click on the link below to access the thermal liner hanging instructions
As recommended, I used the specially formulated Wallrock insulation adhesive to hang it on the walls; this is strong stuff and you need a lot of it but it does hold it in place (although there is a bit of holding until the adhesive sets). It is a little strange that the adhesive comes in tubs of 5kg and 10kg, but the recommendation is to use 6kg per roll of KV600 – it means that you need to go for the 10kg pack, even if you want to do just one roll, so you will have excess adhesive.
The video below shows you exactly how the Wallrock thermal liner is hung on the walls.
The KV600 is about twice the price of the normal Wallrock thermal liner, however the rolls are twice the size so each one covers an area of 15m2. The main advantage for me though is that it is a little bit thicker (4mm as opposed to 3.2mm thick), which is the key to increased energy efficiency. Once it is up on the walls you can paint over it as required.
First of all I can confirm the thermal liner does work. However much like secondary glazing versus double glazing, it does not provide the same level of energy efficiency as installing 100mm of internal wall insulation. It works though, and it is significantly cheaper. I required just under 2 rolls of thermal liner covering and with the adhesive my total outlay for the materials was just over £200. To do the same job with internal wall insulation would have cost me well over £1,000 and despite increased energy efficiency, my room would have become smaller.
One of the added advantages of installing the Wallrock KV600 Thermal Liner was its ability to cover the cosmetic cracks in the room. Now since I live on this busy road, large vehicles are going to continue to drive past my flat. The thermal liner has the ability to move very slightly so gone are the days of visible cracks in the room.
One of the things I could not accurately assess is the savings it has made on my bills. While certainly increasing the comfort of the room in question, I cannot say whether there have been significant savings on my bills – mainly because the bloody energy companies keep putting my bill up! Therefore it is impossible for me to say it will pay back within a certain timescale.However I can conclusively say it does increase the energy efficiency of the walls in my home!
As a final tip – if you are going round the corners of rooms with the thermal liner, I suggest cutting it as per the diagram below.
This ensures that the thermal liner fits more snuggly around the room!
Advantages of Wallrock Thermal Liner (KV600)
Wallrock thermal liner is significantly cheaper than either internal or external solid wall insulation
A noticeable increase in energy efficiency – the room certainly doesn’t get cold as fast when the heating turns off
Wallrock thermal liner covers the cracks and ‘moves’ with the building so the room will remain crack free (fingers crossed!)
It does a job and doesn’t steal significant square footage of the room.
Another option is AeroTherm insulation paste. Just a 1mm layer on walls can reduce heat loss from rooms by 35%.
Installing Underfloor Heating with Suspended Timber Floors
In our home energy surveys, we encounter some interesting properties on our travels. One property we recently Green Deal assessed, located in North London, was going through a major retrofit, including the installation of an air source heat pump with underfloor heating.
Underfloor heating we would say is a nice to have as the ability to walk on a nice warm floor even in the midst of winter is definitely a really pleasurable experience. In addition, provided you have a well-insulated property; it can be a much more efficient way of heating your property compared to using radiators. This is because the temperature the floor is heated to is much lower than trying to heat with radiators, hence less energy is required; and since heat rises a more even distribution of heat can be provided.
Now, the property in question was a Victorian semi in Primrose Hill, with solid walls and suspended timber floors throughout. Retrofitting underfloor heating and insulation on suspended floors involves a different process than if you are looking to do the same with a solid concrete floor so please bear that in mind as you read this article. The process for installing underfloor heating and insulation on a solid concrete floor can be found here.
Process of installing underfloor heating on a suspended timber floor
In this section we look the installation process for a wet underfloor heating system, although in practice you could also install an electric ‘dry’ system. We recommend going for a wet system as this is better suited to heating larger surface areas like your living room and kitchen.
Installing the insulation
1. Prior to thinking about expensive measures like renewables, you first need to insulate the envelope of the house (loft, walls and floors). In this instance it is an absolute must before starting the installing of the underfloor heating system. As mentioned the heating works at lower temperatures than conventional systems so it is imperative the heat they produce doesn’t escape, which will be the case if you get insulation.
As the photo shows, the first thing you do is fix some battens to the sides of the joists, whilst leaving enough headroom for the heating pipes and screed that will go above that.
2. Having put this in place you then install polystyrene boards like Celotex or Kingspan of variable thickness. The precise thickness of boards installed can vary from 25mm of insulation to 150mm of insulation as long as you leave a decent air gap between the boards and the ground to allow for ventilation and the prevention of damp
In the photo I made out the thickness to be 75mm, which was fixed between the joists of the whole floor area.
3. The next step is to install the heating pipes, which are then fixed to the top of the insulation boards as shown on the photo below. These underfloor coils need to be aligned close enough together to ensure there are no cold spots under the floor.
Applying a level of screed
4. This is then followed by a layer of screed (made of a combination of cement and sand), which is placed over the pipework to protect the pipes from collapsing when people stand or furniture is laid on the floor. To provide adequate protection and to ensure the floor isn’t too hot, the coils have to be buried with a decent level of screed material.
Floor Finish
5. A range of floor finishes can be applied to the screed layer including tiles, veneer or wooden boards. This entirely depends on your taste and preference. In my property example the home owner went for a veneer oak finish.
Underfloor heating with Renewables
It is also worth mentioning that underfloor heating works especially well with renewable heating solutions like air source heat pumps since they produce hot water at lower temperatures than traditional gas fired central heating systems. In addition since they are producing hot water at minimum cost once they have been installed they really do make the running of the underfloor heating system very economical.
If you have had a heat pump or solar thermal installed in the last couple of years give us a ring to see if you could benefit from the Renewable Heat Incentive which is a subsidy payment designed to help fund the installation of renewable heating solutions. Call us on 0208 144 0897 for more details.
Installing Underfloor Heating with Solid Floors
When we go out to do our Green Deal Assessments, we encounter some interesting properties on our travels. One property we recently Green Deal assessed, located in London, was going through a major refurbishment, including the installation of underfloor heating.
Underfloor heating if you have never tried it, is a real luxury; the ability to walk on a nice warm floor even in the midst of winter is definitely a most pleasurable experience! In addition, provided you have a well-insulated property; it can be a much more efficient way of heating your property compared to using radiators. This is because the temperature the floor is heated to is much lower than trying to heat with radiators, hence less energy is required and when heat rises a more even distribution of heat is achieved.
Now, the property in question was a 1975 town house in West Kensington, with cavity walls and solid floors throughout. Retrofitting underfloor heating and insulation on solid floors involves a different process than if you are looking to do the same with a suspended timber floor so please bear that in mind as you read this guide. The process for installing underfloor heating and insulation on a suspended timber floor can be found here.
Process of installing underfloor heating on a Solid Floor
In the following guide we look at installing a wet underfloor heating system, although you can install electric ‘dry’ systems.
Installing the insulation
1. Prior to laying the anything on the solid floor, you first need to insulate the envelope of the house (loft, walls and floors). This is an absolute must before starting the installing of the underfloor heating system. As mentioned they work at lower temperatures than conventional heating systems so it is imperative the heat the produce doesn’t escape, so we strongly recommend doing the insulation first, otherwise your new heating solution could essentially not work.
The first photos shows a roll of water proof membrane, which is laid out on the concrete floor. This acts as a vapour barrier that will also prevent damp from rising in the floor.
2. Having put this in place you can then install polystyrene boards like Celotex or Kingspan of variable thickness. The precise thickness of boards installed can vary from 25mm of insulation to 150mm of insulation. However on concrete floors the more insulation you put in, the more room height you sacrifice, although obviously the less heat will escape into the ground. It is vital that you don’t run the underfloor heating coils directly onto the concrete floor without first laying insulation otherwise the majority of the heat will be lost into the ground.
In the photo below I made out the thickness to be 75mm, which was added throughout the ground floor area.
3. The next step is to install the heating pipes, which are then fixed to the top of the insulation boards as shown on the photo below. These underfloor coils need to be aligned close enough together to ensure there are no cold spots under the floor.
4. This is then followed by a layer of screed (made of a combination of cement and sand), which is placed over the pipework to protect the pipes from collapsing when people stand or furniture is laid on the floor. To provide adequate protection and to ensure the floor isn’t too hot, the coils have to be buried within 65mm of screed.
5. A range of floor finishes can be applied to the screed layer including tiles, veneer or wooden boards. This entirely depends on your taste and preference. In my property example the home owner went for a carpeted finish, which meant carpet underlay went in before the carpet was rolled out.
Underfloor heating with Renewables
It is also worth mentioning that underfloor heating works especially well with renewable heating solutions like air source heat pumps or solar thermal since they produce hot water at lower temperatures than traditional gas fired central heating systems. In addition since they are producing hot water at minimum cost once they have been installed they really do make the running of the underfloor heating system very economical.
If you have had a heat pump or solar thermal installed in the last couple of years give us a ring to see if you could benefit from the Renewable Heat Premium Payment which is a cashback incentive to help fund the installation of renewable heating solutions. Call us on 0208 144 0897 or send us an email to Mailbox@TheGreenAge.co.uk
Cavity walls and the benefits of insulating them
August 11, 2013
Cavity wall insulation has been around for years, and it remains one of the best ways to help reduce your energy bills. So we at TheGreenAge thought that we should give you a quick guide on what you need to know so that you can maximise energy efficiency of your home. See the video below for a quick introduction!
How do you know if you have cavity walls?
When we do our Green Deal Assessments with clients in London, we stress the importance of insulating the envelope of the property, which includes the roof, the walls and the floor. The first thing we do therefore is check whether the home has cavity or solid walls. There are several simple ways to check this.
Understanding the property age
Generally speaking, properties built after 1930 will have cavity walls. Those built prior will have a solid brick walls. But that isn’t definitive as we encounter many semi-detached properties in London suburbia (Harrow, Edgware, Watford, St Albans, Ealing and so forth) that actually have solid walls, despite their age!
Checking the brickwork
Check your brickwork. If you have bricks end to end across the whole wall, it is a cavity wall (also called a stretched bond – see diagram below). If the bricks are a mixture of ‘stretchers’ and ‘headers’ where there are short bricks and long looking bricks, then you have a solid wall (i.e. no cavity).
Measuring the wall thickness
Sometimes walls are rendered, which makes things a little more tricky since you can’t see the pattern of the bricks. If this is the case, you can try measuring the thickness of the wall through a window or doorway. If it is less than 260mm, it is likely a solid wall. Anything thicker is more likely to be a cavity.
Other ways to check is by looking at un-plastered areas of the house (in the staircase, airing cupboards or in the loft) where you should see either a layer of breeze-block or a layer of brick.
Checking for existing cavity wall insulation
So you have a good idea of whether you have a cavity or not. The next step is to check whether it has been insulated. Modern properties built from the 1980’s onward are generally insulated when they are built, since it is now part of standard building regulations. Homes built prior to this date may or may not have insulation. If it was insulated it after construction date it would have been done so by injecting insulation into the cavity through holes in the wall. You can usually spot where these holes have been covered up on a brick wall along the mortar lines.
So what if you still can’t tell? In this case it is time to call in a professional to come to your property and inspect the potential cavity.
When a professional energy assessor (like one from our team) comes round to your property they will undertake a borescopic examination. This involves drilling a small, non-intrusive hole in the mortar (above the damp coursing) and checking with a borescope (a camera on the end of a fibreoptic cable) for any insulation. We show you how this is done in the video below:
What could Cavity Wall Insulation do for me?
So you know you need insulation, what is it worth exactly? Typically cavity wall insulation costs around £500-1,000, depending on the size of the property and the walls needing to be insulated.
But it can save you serious money on your heating. A detached or semi-detached property could be looking at savings of up to £500 a year, depending on the occupants and how you use your heating. Terraced properties could expect savings of £200-300.
So the payback here is pretty good. You should save enough in the first few years to cover the initial costs of getting the cavities insulated.
In addition, it is well worth remembering that all evidence points to energy prices continuing to skyrocket – over the last 8 years, energy prices have increased by 10% each year. Therefore the quicker you get your walls insulated the better!
If you would like to read more about cavity wall insulation, see our full guide here.
Don’t wait to swap your light bulbs to LED!
August 6, 2013
Change your light bulbs now
So you are contemplating getting some energy saving light bulbs in your home, but you’re thinking, ‘I’ll wait until they blow, there’s no point in changing them while they are still working’. This is a real misconception, because as I will explain, it is worth switching over immediately.
So we are going to look at this using two scenarios. In the first, I will use a standard halogen bulb for a year (about 2,000 hours), replacing it when necessary. The average halogen bulb lasts for about this length of time, whereas an LED lasts up to 20 years, and we have assumed paying for replacements in the below scenarios as a result of this.
Now we always bang on about how long LED bulbs last (40,000 hours if you need reminding!), but what I am trying to show you here is that even taking into account they cost £15 or so to buy initially, they still pay back within the first year. Many people assume that in the short term the cost of LED bulbs outweigh the savings made. This simply isn’t true, especially in parts of the home like the lounge, where you will be using your lights for at least 5 hours a day. If you are using your lights at this sort of rate, then it really is worth switching right now. Remember this is just replacing one halogen bulb with an LED one – imagine if you were to replace 20 – the total cumulative savings on your energy bills will be massive!
Now some people still go for the old style energy saving bulbs technically known as CFL bulbs. These are low energy, and although they aren’t quite as efficient as LED’s, they are far better than halogens or incandescents. Unfortunately, CFL’s also contain mercury, and as such we recommend LED’s as the most economic and environmentally friendly option to light your home.
What about other areas of the home?
In our second scenario we look at rooms where the lights tend to be on for shorter periods of time, like the bathroom and the bedroom. Here, there is still clear saving to be made by switching to LED, although it will take a little longer to get your money back. The graph shows that in a room where you only use your lights for around 2 hours a day, it will take about 2 years to pay back for the cost of LED’s, so even in a lesser used room, it is worthwhile changing over to LED bulbs sooner rather than later.
So LEDs really are the way to go if you want reliable, cheap lighting in your home, but the real take home message here is that waiting till they blow doesn’t make sense since in that time there is a high chance the LED equivalent bulbs will have already paid for themselves!
Unlike the previous Green Deal scheme which was loan operated, the Green Homes Grant offers grants of up to £5000 and £10,000 to wholly or partially cover the full cost of the energy saving measure.
The Green Homes Grant was set up to help improve the energy efficiency of properties across the UK, since many of the properties we live in are very inefficient, with solid walls, old heating systems and very little insulation. This scheme allows people to improve their homes without having to stump up the entire upfront costs of the works.
How does the Green Homes Grant work?
The Green Homes Grant is divided in to two separate grants, which each have different eligibility criteria.
£5000 – available to any home in England that fits the correct criteria for the specific measure. This grant covers 2/3’s of the full cost and caps at £5000. There will be a remainder in all cases using this grant and it will be paid as a customer contribution.
£10,000 – available to any homeowner receiving certain benefits listed here, and whose home fits the correct criteria for the specific measure. This grant covers 100% of the full cost up to £10,000 and the remainder is paid as a customer contribution.
e.g. Fitting external insulation on a small terraced house (approx 50sqm), using the £5000 green homes grant
The average supply and fit cost of external wall insulation is £120 per sqm (inclusive of materials, labour, VAT, skip hire, any extra remedial work required, scaffolding). Therefore, a 50sqm house would cost £6000.
In this case, 2/3’s of the full cost is £4000, so this is how much the Green Homes Grant would cover. The homeowner would pay the remainder of £2000.
e.g. Fitting external insulation on the same size house (50sqm), using the £10,000 Green Homes Grant
As above, the total cost of the works would amount to £6000. With the £10,000 grant, the whole £6000 would be covered by the Green Homes Grant and there would be no customer contribution.
If the house were bigger (for instance, 100sqm) the total cost would be £12,000, the Green Homes Grant would cover £10,000 of the amount and the homeowner would have to pay £2000.
Who can get the Green Homes Grant?
In theory, any home in England can access the Green Deal considering you are eligible, but the scheme has been specifically tailored to the private home owner or the private rental sectors. The reason being is that the social housing sector already has several ways in which improvements are funded and undertaken – namely the ECO scheme.
The following section talks a bit more about how the Green Homes Grant process works end-to-end – starting with a finding a Trustmark approved installer to quote for the works.
Find a Trustmark approved installer to quote you for the works. The installer will also have to be registered to specific certifications regarding the measure they are installing – MCS/PAS2035. It is recommended to get three quotes for comparison.
When you have submitted your application, it will take a few weeks until you receive your Green Homes Grant voucher. Work must not start before you receive the voucher.
Your installer will be notified when you receive the voucher, however it is always a good idea to let them know yourself and arrange a start date for the work to begin.
An installer will complete the work and you as the customer should be benefiting from the energy improvements.
How does the Green Homes Grant help improve homes?
By installing energy efficient measures in your home, it will help protect the environment, and lower your energy bills.
Types of measures currently covered in the Green Homes Grant scheme:
How does the Green Homes Grant help improve energy awareness?
The Green Homes Grant provides homeowners with knowledge of energy efficient home improvements. In turn, better energy awareness should drive occupiers to use their energy more wisely, which should drive down the cost people pay. For example: reducing the temperature of the hot water cylinder thermostat, installing central heating thermostats in the correct location, reducing water levels in kettles, washing clothes in ‘eco-mode’, and turning off unused high energy usage appliances like chest freezers should all help with lower energy bills.
We list 100 ways to save energy in the home here – even if you adopt a few, you should see some nice energy savings on your utility bills.
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