How it works
How does our one-stop retrofit service work?
The Cosy Homes Oxfordshire service centres on a whole house approach to home retrofit, providing a full, one-stop-shop service for homeowners who want to increase the energy efficiency of our homes.
Once you register your home you will be assigned an expert Retrofit Coordinator based on your needs, who will act as your single point of contact throughout – through there will likely be other Coordinators involved behind the scenes depending on the expertise needed for your specific home.
On this page we’ll explain how the service works including: the initial steps of home assessment and whole house plan, an outline of the full process, where costs come in, and the different routes to get started.
Hoping to take advantage of the Green Homes Grant to retrofit your home? Head to our Green Homes Grant webpage to find out more.
Interactive Cosy Home
Explore our interactive Cosy House to see the most common energy efficiency measures implemented during a home retrofit, including boiler replacements, insulation, and installing solar panels. You’ll also discover how much money and carbon emissions implementing these measures could save.
Cavity wall insulation
In uninsulated homes, around a third of heat loss is through the walls. This is particularly an issue in homes with cavity walls – which are made up of two walls (the outer usually brick; the inner usually brick or concrete) with a gap between them. Cavity wall insulation reduces this heat loss by filling the gap between the two walls – the ‘cavity’ – with insulating material which prevents or reduces the leakage of heat.
How does cavity wall insulation work?
The most common method for fitting cavity wall insulation is for insulation material to be injected into the cavity – usually mineral wool, polystyrene beads, or polyurethane foam. This is done by drilling small holes in the outside walls at various intervals, injecting the material through the holes, and then filling the holes back up so they are not noticeable.
This procedure must be done by a professional and reputable installer to ensure it does not cause issues. If you work with Cosy Homes Oxfordshire on your home retrofit you’ll have access to our network of trusted contractors, who we will contact and manage for you.
What homes does this measure suit?
Cavity wall insulation is only relevant for homes which have cavity walls. If your home was built after the 1920s it will likely have cavity walls. If your home was built before 1920 it will probably have solid walls, and so solid wall insulation is more relevant for you.
Some homes with cavity walls will already have them insulated – it was common practice from the 1990s onwards to add insulation into cavity walls during construction.
Cavity wall insulation is not suitable for flats, unless you have agreement from the owners of all flats in your block to insulate the whole block.
If you aren’t sure what type of walls your home has, Cosy Homes Oxfordshire can help with that through our home assessment and Whole House Plan service. Simply register your home with us and we’ll be in touch to book your home assessment.
What are the expected costs and savings?
As with any retrofit measure, the potential carbon and cost savings vary depending on the type and size of your home. Cavity wall insulation is a relatively simple measure which makes a big difference, and can reduce heat loss by up to a third – so it’s likely you can make substantial savings within 5 years of the insulation being installed.
The Energy Savings Trust predicts costs and savings as below (April 2019 data). It’s worth noting that you might be able to reduce these costs by carrying out the work at the same time as other home retrofit improvements through our Whole House Plan approach.
| Detached house | Semi-detached house | Mid terrace | Bungalow | Flat | |
|---|---|---|---|---|---|
| Typical cost (£) | £610 | £475 | £390 | £460 | £345 |
| Energy bill savings (£/year) | £280 | £165 | £105 | £110 | £85 |
| Carbon emissions diverted (kgCO2/year) | 1150kg | 680kg | 430kg | 460kg | 335kg |
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Solid wall insulation
In uninsulated homes, around a third of heat loss is through the walls. The best way to reduce heat loss through walls is dependent on the type of walls your property has.
Solid walls are walls with no gap, so they cannot be filled with cavity wall insulation, but they can be insulated by adding insulating material to the inside (Internal Wall Insulation or IWI) or outside (External Wall Insulation or EWI) of the wall to reduce heat loss.
How does solid wall insulation work?
There are two ways to insulate solid walls: internally and externally.
Internal wall insulation can be done by fitting rigid insulation boards to the wall. It can also be done by building a stud wall – a timber frame which sits in front of the solid wall. The gaps in the frame are then filled with insulation material such as mineral wool fibre. This will slightly reduce the floor area of the room. You’ll also need to ensure any issues with damp are dealt with prior to undertaking the work.
External wall insulation involves a layer of insulation material being attached to the wall on the outside of the home, which is then covered with a special type of plasterwork or cladding which can then be decorated over. This is a less disruptive procedure than internal wall insulation. It also has the added benefits of improving weatherproofin and sound resistance, as well as protecting the brickwork and so expanding the lifespan of the walls. However, it may require planning permission, depending on your local council.
Solid wall insulation work and ventilation
Solid walls allow water vapour to move freely through the building, as it can travel through the bricks and stones that the walls are made up of. When you add insulation, this can change the way the water vapour behaves – cutting down draughts, but also potentially causing water vapour to condense on the inside of walls (as the wall is colder than previously).
Because of this, it’s imperative that when you fit solid wall insulation you also take into account water vapour to ensure you don’t cause ventilation and damp issues in your home later down the line. This could be about using ‘breathable’ insulation materials or creating a vapour barrier.
A professional and reputable installer will ensure that this is taken into account. If you work with Cosy Homes Oxfordshire on your home retrofit you’ll have access to our network of trusted contractors – so you won’t need to worry about this.
What homes does this measure suit?
If your home was built before 1920 it likely has solid walls, and it’s very unlikely that they are insulated (unless you’ve already had this procedure done yourself). You can also identify the type of walls your home has by their width. If a brick wall is more than 260mm thick it is probably a cavity wall, but if it is narrower it is more likely to be a solid wall. If you aren’t sure what type of walls your home has, Cosy Homes Oxfordshire can help with that through our home assessment and Whole House Plan service. Simply register your home with us and we’ll be in touch to book your home assessment.
What are the expected costs and savings?
Solid wall insulation will cost more than insulating a standard cavity wall, but you’ll likely make larger cost and carbon savings too.
The Energy Savings Trust estimates the cost of solid wall insulation to be around £7,400 for internal wall insulation and £13,000 for external wall insulation (based on a typical semi-detached home). Please note that by making improvements to You might be able to reduce these costs by carrying out the work at the same time as other home retrofit improvements through our Whole House Plan approach. The Energy Savings Trust predicts savings as below (April 2019 data).
| Detached house | Semi-detached house | Mid terrace | Bungalow | Flat | |
|---|---|---|---|---|---|
| Energy bill savings (£/year) | £375 | £225 | £145 | £150 | £105 |
| Carbon emissions diverted (kgCO2/year) | 1540kg | 930kg | 590kg | 620kg | 425kg |
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Loft or roof insulation
In an uninsulated home up to a quarter of heat lost is through the roof. Installing insulation in your roof or loft is a great way to reduce heat loss and make your home more energy efficient – saving money and cutting carbon emissions at the same time.
How does loft/roof insulation work?
Insulating a roof is easiest when there is easy access to the roof space. In this instance, insulation is normally done by using rolls of mineral wool insulation. This material will be laid along the floor and the walls of the roof space.
The thicker the roll of insulation used, the less heat loss there will be. So, even if you already have roof insulation in your home, it’s worth checking if it could be further improved and thickened.
If you want to use the roof space as storage, you’ll then need to lay boards over the insulation material on the floor of the roof. It’s important to leave a gap between the insulation and boards to allow ventilation and avoid damp and mould – as well as ensuring the insulation is not squashed, reducing its effectiveness.
If you want to turn the roof space into a usable attic room or living space it will need further work alongside the roof insulation, ensuring all areas of the walls and ceiling are insulated, and then adding a layer of plasterboard on the inside of the insulation to create the walls of the room.
If your roof space is difficult to access, the best option is likely to be blown insulation. This involved a professional using specialist equipment to blow insulation into gaps in the roof – usually mineral wool fibre, treated cellulose, or polyurethane foam.
If your home has a flat roof it will usually be insulated from above, with a layer of rigid insulation board added on top of the roof. This can be combined with internal roof insulation if the property has only some areas of flat roof, rather than an entirely flat roof.
As with any type of insulation, you need to make sure that the roof is dry and in good condition before any insulation is added. This is not a DIY job and does need a professional and reputable installer to ensure it is done properly and does not cause issues with damp or ventilation down the line. If you work with Cosy Homes Oxfordshire on your home retrofit you’ll have access to our network of trusted contractors, who we will contact and manage for you – so you won’t need to worry about this.
What homes does this measure suit?
Whether your roof is slanted or flat, used as a loft space or remains empty, roof insulation is suitable for most homes – but the insulation method will vary, as outlined above. Roof insulation may not be suitable for flats within buildings with a shared roof space, as you would need permission of all flat owners within the building.
If you want to check whether you have existing roof insulation or not, and whether this could be improved, the best place to start is by getting a retrofit professional to assess your home. We can help you with this through our home assessment and Whole House Plan service. Simply register your home with us and we’ll be in touch to book your home assessment.
Roof insulation work and ventilation
Insulation stops heat escaping from living spaces, so it will make your loft space cooler, which could introduce or worsen existing damp or condensation problems. This means that when you are installing roof insulation you need to also be thinking about how to improve ventilation in the space to avoid issues later down the line.
A professional and reputable installer will ensure that this is taken into account. If you work with Cosy Homes Oxfordshire on your home retrofit you’ll have access to our network of trusted contractors, who we will contact and manage for you – so you won’t need to worry about this.
What are the expected costs and savings?
Loft insulation is effective for at least 40 years, so it should pay for itself many times over. The Energy Savings Trust predicts costs and savings as below for two different instances.
| Detached house | Semi-detached house | Mid terrace | Bungalow | |
|---|---|---|---|---|
| Typical cost (£) | £395 | £300 | £285 | £285 |
| Energy bill savings (£/year) | £250 | £150 | £135 | £210 |
| Carbon emissions diverted (kgCO2/year) | 1000kg | 610kg | 550kg | 860kg |
| Detached house | Semi-detached house | Mid terrace | Bungalow | |
|---|---|---|---|---|
| Typical cost (£) | £290 | £240 | £230 | £280 |
| Energy bill savings (£/year) | £25 | £14 | £12 | £19 |
| Carbon emissions diverted (kgCO2/year) | 95kg | 55kg | 50kg | 80kg |
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Floor insulation
Floors on the ground floor – alongside walls and roofs – are a common area that heat is lost from a home.
Floor insulation usually refers to installing insulation material around the floor space on the ground floor of a property. However, if you have floors on upper floors which are above unheated spaces e.g. a garage, you could be losing heat here too and therefore require insulation.
How does floor insulation work?
Heat loss through floors is more pronounced in homes which have ground floors made of solid concrete, which is most newer homes. These can be easily insulated by adding rigid insulation boards on top of the flooring. It can also be insulated internally but this will require replacing the concrete floor, and so is best done when the flooring already needs replacing.
Older homes may have suspended timber floors. If you have a suspended timber floor you will likely be able to see air bricks or ventilation bricks on the outside walls of your home that are below floor level. It may seem the obvious solution to insert insulation into these air bricks to close the gaps, but you should never do this. These air or ventilation bricks are needed for ventilation, to stop damp and therefore stop the floorboards from rotting.
To properly insulate timber floors you need to lift the floorboards and lay insulation between the joists – and it’s best to get a professional installer to do this. A professional and reputable installer will ensure that this is taken into account. If you work with Cosy Homes Oxfordshire on your home retrofit you’ll have access to our network of trusted contractors, who we will contact and manage for you – so you won’t need to worry about this.
You can also reduce heat lost through flooring by draught-proofing, sealing gaps between floors and skirting boards to reduce draughts.
What homes does this measure suit?
Any home which has a ground floor (i.e. not flats) can improve energy efficiency and reduce the cost of energy bills by insulating the floors.
What are the expected costs and savings?
The Energy Savings Trust estimates the cost of floor insulation to be between £520 and £1,300 depending on the circumstances. They predict cost savings as below (April 2019 data).
| Detached house | Semi-detached house | Mid terrace | Bungalow | |
|---|---|---|---|---|
| Energy bill savings (£/year) | £75 | £45 | £30 | £70 |
| Carbon emissions diverted (kgCO2/year) | 310kg | 185kg | 120kg | 250kg |
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Draught proofing
Draught proofing is a cheap and effective way to reduce energy use in a home (or other type of building). It refers to filling in gaps in the building, often found with open chimneys and gaps around windows and doors.
How does draught proofing work?
Allowing air into a building is crucial to reducing condensation and damp, allowing fresh air to circulate. However, you do not want uncontrolled air coming into the building – known as draughts. Draughts let in too much cold air and let out too much heat from inside the home. Draught proofing works by blocking up gaps in the home to keep the heat in and the cold air out, meaning that the home remains comfortable even when you turn down your thermostat.
What homes does this measure suit?
Most types of home will benefit from draught-proofing, especially around windows and doors. This is especially true if you have single-glazed windows. Otherwise, draught-proofing is for homes with obvious draughts, for instance from an open chimney.
What are the expected costs and savings?
Based on a typical semi-detached on-gas property in the UK, Energy Savings Trust predicts that draught-proofing around windows and doors could save you around £20 per year.
If you have an open chimney, draught-proofing your chimney when you’re not using it could save around £15 per year.
Draught proofing can be a fairly cheap measure to put into place – depending on how much and which areas of the home you want to draught proof. You can probably install draught-proofing around windows and doors yourself at a basic level. However, we would always recommend getting professional advice in order to maximise the energy savings – professional installers will be able to identify the right materials to use and where, as well as recommending complimentary measures.
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Boiler replacement
55% of our annual energy spend goes on heating. This means it’s also an area where a big difference can be made in cost and carbon savings.
Most homes in the UK are heated using a central heating system with a single boiler, usually run on mains gas. Some boilers can be very inefficient, and they’re also a fossil fuel heavy way of heating your home. So replacing your boiler can be a great way to reduce energy bills and carbon emissions.
How does boiler replacement work?
Central heating systems are the most common form of heating in UK homes. This is where a single boiler heats up water, which is pumped through pipes to radiators placed throughout the house – as well as providing hot water to taps in the kitchen and bathrooms. Most boilers run on mains gas – but can also be oil, LPG (tank gas), coal, or wood.
However, not all boilers are the same. If your boiler is an older model it may be inefficient, and you should consider replacing it with a more modern model – or look at other options for heating your home, such as heat pumps or biomass boilers.
If your boiler was installed before 2005, it is likely inefficient. Since 2005 the vast majority of boilers installed in the UK have been condensing boilers, which are significantly more efficient. Condensing boilers are able to recover much more heat from the burning gas through larger heat exchangers.
You should always ensure you are dealing with a professional and reputable installer for boiler replacement, especially ensuring they are Gas Safe registered. If you work with Cosy Homes Oxfordshire on your home retrofit you’ll have access to our network of trusted contractors, who we will contact and manage for you – so you won’t need to worry about this.
Some homes in the UK are heated with electric storage heaters. This is an expensive and carbon intensive method of heating, and so you should also consider replacing this system with an efficient boiler system, biomass boiler, or heat pump.
What homes does this measure suit?
If your home is heated through a central heating system, with a single boiler which was installed before 2005 you should consider boiler replacement. If you aren’t sure when your boiler was installed then look at the flue – if it’s made from metal it’s unlikely to be a modern, condensing boiler. Condensing boilers also have plastic pipes coming out of the bottom, through the wall and into a drain – so if yours doesn’t have this, it’s another sign that it’s an older model.
If your home is heated through electric storage heaters, you should also consider boiler replacement. This is more common for flats.
What are the expected costs and savings?
The costs for replacing a boiler vary depending on the property, but Energy Savings Trust predict that a straightforward gas boiler replacement plus thermostatic radiator valves will typically cost about £2,300 – excluding radiators.
The Energy Savings Trust predicts savings as below (April 2019 data), depending on the model of boiler you are replacing. The top of the range represents replacing a G-rated boiler with an A-rated boiler, and the bottom of the range represents replacing a D-rated boiler with an A-rated boiler.
| Detached house | Semi-detached house | Mid terrace | Bungalow | Flat | |
|---|---|---|---|---|---|
| Energy bill savings (£/year) | £315-£170 | £205-110 | £175-95 | £165-90 | £85-45 |
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Air source heat pumps
Air source heat pumps (ASHPs) absorb heat from the air outside and use it to heat your home and hot water. They use electricity to run, but the heat output is much higher than the electricity input – so they’re a very low carbon and low cost form of heating.
How do air source heat pumps work?
Heat from the air is absorbed at low temperature into a fluid. This fluid passes through a compressor, increasing the temperature, and transfers that higher temperature heat to the heating and hot water circuits of the house.
There are two main types of ASHP: air-to-water and air-to-air:
- Air-to-water pumps absorb heat from the air and transfer that heat into water, which is then distributed around your home via a central heating system. This is the most common form in the UK.
- Air-to-air pumps require a warm circulation system to move warm air around the home, but do not provide hot water.
What homes does this measure suit?
Air source heat pumps are not right for every home, and suit homes which:
- Have enough space outside the home where a unit can be fitted to a wall or placed on the ground – if you have large grounds you may also consider a Ground Source Heat Pump
- Have an existing central heating system
- Are well insulated and draught proofed to minimise heat loss.
If this doesn’t sound like your home, you may benefit more from replacing your boiler with a more efficient model.
If you aren’t sure whether an ASHP is right for your home, we’d recommend getting a retrofit professional to assess your home. We can help you with this through our home assessment and Whole House Plan service. You may also need to get planning permission, which we can also support with. Simply register your home with us and we’ll be in touch to book your home assessment.
What are the expected costs and savings?
Typical installation costs will be around £9,000 – £11,000 according to the Energy Savings Trust.
Savings will vary depending on what heating system you are currently on. You will make the biggest cost savings if your home is currently heated using electric storage heaters. If you currently have a gas boiler you may not see substantial cost savings, but there will be substantial carbon savings.
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Ground source heat pumps
Ground source heat pumps (GSHPs) extract heat from the ground using pipes buried in the garden and use this to heat your home and hot water. This is a low cost and low carbon method of heating.
How do ground source heat pumps work?
A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe, called a ground loop, which is buried in your garden. This is usually a horizontal trench about a metre below ground.
The fluid then passes through a compressor that raises it to a higher temperature, which can then heat water for the heating and hot water circuits of the house. The cooled ground-loop fluid passes back into the ground where it absorbs further energy from the ground in a continuous process as long as heating is required.
The ground stays a fairly constant temperature throughout the year, and so the heat pump can still be used in winter.
What homes does this measure suit?
The key factor for ground source heat pumps is that they are laid in the ground, so they are only suitable for homes with substantial outside space.
What are the expected costs and savings?
The energy savings trust estimates that it costs £14,000-£19,000 to install a ground source heat pump. Running costs will vary depending on the size of your home and how much energy is needed to heat it.
Savings will vary depending on the heating system you are starting with, but the Energy Savings Trust predicts savings as below (April 2019 data).
| Moving from: average gas heating system | Moving from: average oil heating system | Moving from: average electric heating system | |
|---|---|---|---|
| Energy bill savings (£/year) | £25-30 | £20-30 | £1000-1090 |
| Carbon emissions diverted (kgCO2/year) | 2.5-2.7kg | 3.9-4.2kg | 3.6-3.9kg |
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Double or triple glazed windows
Windows are a key area within a home where heat is lost. This can be reduced through draught-proofing to fill any gaps, as well as ensuring windows are double or triple glazed. As well as reducing energy bills and carbon emissions, this will also reduce noise from outside entering your home.
How does glazing windows work?
The energy performance of a window depends on how well it stops heat from passing through it, as how much sunlight travels through the glass, and how little air leaks around the window. Single glazed windows are not very effective at stopping heat loss, as they are made of a single pane of glass.
Double-glazed windows are windows which have two sheets of glass with a small gap between them. Triple-glazed windows have three sheets of glass and two gaps, improving insulation further.
Windows can be made of many different materials, which have differing impacts on the energy performance of the property. These are measured using an energy rating called a u-value, on a scale from A++ to E.
When replacing windows, it’s very important to consider ventilation too. More efficient windows will likely lead to more condensation due to reduced ventilation – so you need to incorporate vents in the replacement windows.
We’d always recommend consulting with a retrofit professional to assess your home if you intend to change your windows to ensure you’re making the right choice. We can help you with this through our home assessment and Whole House Plan service. Simply register your home with us and we’ll be in touch to book your home assessment.
What homes does this measure suit?
Most homes can benefit from improving the glazing on windows. However, if you live in a listed building or conservation area you may not be able to change your windows.
What are the expected costs and savings?
Installation costs will vary depending on the type and number of windows needed. Savings will also vary depending on the home, but the Energy Savings Trust predicts savings as below (April 2019 data) for moving from an entirely single-glazed property to double-glazed. The range reflects the energy efficiency rating of the window (top of the range A++, bottom of the range C).
| Detached house | Semi-detached house | Mid-terrace house | Detached bungalow | Flat | |
|---|---|---|---|---|---|
| Energy bill savings (£/year) | £120-100 | £85-70 | £65-50 | £60-50 | £40-30 |
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Heating controls
Heating represents around 55% of the total annual spend on energy within a home. Making sure you have a suitable heating system – an efficient boiler or heat pump (air source or ground source) – is key, but so is ensuring that you have control of that heating system.
Installing heating controls will help ensure your home is kept at a comfortable temperature all year round, without using excess fuel to heat your home.
How do heating controls work?
If you have a central heating system, as most homes in the UK do, then you should ideally have the following heating controls in your home:
- Boiler thermostat: sets the temperature of the water that is pumped from the boiler through the radiators.
- Timer or programmer: allows you to automatically switch your heating off when it isn’t needed, for instance overnight.
- Room thermostat: allow the heating to be turned on in a specific room up to the temperature you have set, so that a room does not get warmer than needed.
- Thermostatic radiatior valves (TRVs): reduce the flow of water through the radiator they are fitted to when the temperature goes above its setting.
With these controls you can have a much more active role in your energy usage, scheduling your heating and hot water to go on and off as needed. You should also be able to heat different areas of your homes in different ways, instead of heating the entire home at one temperature.
These controls can be installed or upgraded even if you aren’t planning on replacing your boiler, and can be a simple and cost-effective way to make a big difference on your energy bills and carbon footprint.
What homes does this measure suit?
Improving heating controls is important for any home. However, it will have the biggest impact on homes which currently do not have one (or more) of these controls installed or where the controls have been in the home for a long time – as controls like thermostats are much more accurate today.
What are the expected savings?
The Energy Savings Trust estimates that you can save £60 on your energy bills per year and reduce the carbon emissions from your home by 310kg per year by installing and using a programme, room thermostat, and thermostatic radiatior valves.
We all have different temperatures that we’re comfortable in, but bear in mind that reducing your thermostat by just 1 degree can also save you £75 and 320kg of carbon emissions each year.
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Rooftop solar panels
Solar photovoltaic (PV) panels take energy from the sun and convert it into electricity which can be used to power your home. By installing solar panels on the rooftop of your home you can generate your own renewable electricity, meaning you reduce your energy bills (as you need to buy less electricity) and the carbon footprint of your home.
A typical solar PV array on a home rooftop will save 1.3-1.6 tonnes of carbon emissions every year (Energy Savings Trust).
How do solar panels work?
Solar PV cells are made from layers of semi-conducting material, usually silicon. When light shines on this material electrons become loose, creating a flow of electricity. Solar PV cells are grouped together to form solar arrays, and most PV systems are made up of panels – which can be installed on rooftops or in the ground.
The stronger the sunlight, the more electricity can be generated – though they do not need direct sunlight to work. The electricity generated is direct current (DC) but the electricity used by household appliances is alternating current (AC), so an inverter is installed alongside the PV array to convert the electricity for use in the home.
What homes does this measure suit?
The main consideration with installing solar panels in your home is your roof space. You will need a roof which is ideally south-facing, unshaded (nearby trees, buildings, or chimneys), and has a pitch angle of 30-40 degrees. The amount of suitable roof space you have will determine how many panels you could host on your rooftop, and therefore how much of your electricity needs you could supply.
In order to make the most out of your solar PV array, you should also consider the following factors:
- Insualting your home to keep the heat in for longer, as well as draught-proofing
- Use timers and heating controls to ensure you use more of your electricity during the daylight hours when your PV system is working
- Combine with other renewable systems such as heat pumps or solar thermal panels.
We’d recommend consulting with a retrofit professional to help you make the most of installing solar PV panels on your rooftop. Cosy Homes Oxfordshire can help you with this through our home assessment and Whole House Plan service. Simply register your home with us and we’ll be in touch to book your home assessment.
What are the expected costs and savings?
According to the Energy Savings Trust, the average domestic solar PV system is 3.5kWp and costs around £4,800 to install.
You can expect to generate around 3,700 kilowatt hours of electricity every year and this will contribute 20-30% of your total electricity use, saving up to 1.6 tonnes of carbon emissions each year.
These figures will vary depending on your location within the UK and how much sunlight your PV panels receive.
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
LED light bulbs
Lighting accounts for 15% of a typical UK home’s electricity bill, and something as simple as changing your lightbulbs to a more energy efficient option can reduce this significantly – with the best option usually being Light Emitting Diodes (LEDs).
How do LED lights work?
Traditional light bulbs, also known as tungsten filament, incandescent or GLS (General Lighting Service) bulbs were invented more than 100 years ago and are extremely inefficient, converting only around 5% of the electricity used into light. Halogen lightbulbs are also common and also use filament technology but run at a slightly higher temperature and so are slightly more efficient. These are commonly found in spotlight fittings – often used in high quantities in a room.
LEDs allow electricity to flow through them in one direction to produce a small amount of light. Bulbs for domestic use contain a large number of LEDs so that a bright enough light is emitted. They are significantly more efficient than traditional or halogen lightbulbs – and LED replacements are available for most light fittings, as well as being very cheap.
CFLs use gas inside a glass tube which is charged with electricity until it glows and gives off light. They last much longer than traditional light bulbs and are much more efficient. They are useful for replacing standard light fittings, but not spotlight bulbs.
What homes does this measure suit?
No matter what type of home you live in, replacing inefficient light bulbs is a great way to improve your energy efficiency – reducing energy bills and carbon emissions.
What are the expected costs and savings?
Replacing a single halogen light bulb with an LED of the same brightness will save you up to £2 per year. That may not sound like much – but start adding up how many bulbs you have in your whole home, and it will start to add up to a significant amount for such a simple action.
By replacing all bulbs in your home with LED alternatives, you could save about £40 a year on your electricity bills, according to the Energy Savings Trust.
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Ventilation
When we think of energy efficiency we may initially think of how to keep the heat in to reduce wasted energy. However, it’s just as important to look at ventilation in your home.
Poor ventilation leads to issues with condensation and damp as there is poor air circulation in the home. Controlled ventilation will reduce this, letting fresh air in when needed.
How does ventilation work?
There are a few types of ventilation measures within the home, including:
- Installing extractor fans in rooms where moisture is commonly produced, usually kitchens, bathrooms, and utility rooms – these need to be used at all times when moisture is being produced.
- Underfloor grilles or airbricks which help keep wooden beams and floors dry by allowing gaps in which air can circulate.
- Wall vents which allow small amounts of fresh air into rooms.
- Trickle vents, usually found above modern windows where small vents allow fresh air to trickle in.
- Mechanical Ventilation with Heat Recovery (MVHR) system which consists of a unit and ducts which extract stale air and replace it with fresh air – these are common in new build homes, but if you live in an older building it’s unlike you have one.
Ventilation should always be at the front of mind when undertaking any energy efficiency work in the home. Measures such as insulation and draught-proofing, if not done correctly, can cause issues with ventilation – leading to damp in your home.
That’s why we’d always recommend engaging with a retrofit professional to undertake this work. Cosy Homes Oxfordshire can help you with this through our home assessment and Whole House Plan service. Simply register your home with us and we’ll be in touch to book your home assessment.
What homes does this measure suit?
Ensuring controlled ventilation is important for any home. However, it’s more likely to be an issue if you live in an older property. If you have existing issues with condensation, damp, or mould, you should definitely look at tackling your home’s ventilation.
Which energy efficiency measures does your home need?
With our free Cosy Homes Oxfordshire Plan Builder you can find out – it uses existing data on your home to recommend the best improvements for cost and carbon savings.
Step 1: Home assessment
The first step is for one of our Retrofit Assessors (or sometimes a Retrofit Coordinator, depending on availability) will come and assess your whole house to find out everything we need to know about your existing energy usage and the building itself.
Step 2: Whole House Plan
Your Retrofit Coordinator will then use this information to develop a bespoke Whole House Plan for your home, detailing all the measures you could take to make your home as energy efficient as possible as a whole, with recommendations on the most cost-effective and impactful measures to take forward, and in which order.
It’s then up to you to choose which measures you go ahead with, with the support and advice of your Retrofit Coordinator. If you do decide to go ahead, your Retrofit Coordinator will also manage the delivery of the work, finding trusted contractors, managing health and safety onsite, and checking the quality of delivery once complete. You can see all the steps of the retrofit process in the diagram adjacent.
Our process in full
What costs are involved?
Our home assessment and Whole House Plan service costs £175, which covers the cost of the Retrofit Coordinator’s time and expertise in creating your bespoke plan.
The Whole House Plan gives an idea of the cost if you go ahead with measures – but be aware that there are estimates only and so can be different to the final quotes.
After you’ve reviewed your Whole House Plan with your Retrofit Coordinator you will be sent a Client Services Agreement (CSA) which outlines any additional costs before work can begin on your retrofit – typically a Building Performance Specification and any technical reports needed for contractors to quote. This can cost up to £500.
If you go ahead with your home retrofit, there will be a 5% project charge for our service – also outlined in your CSA. This covers the cost of a Retrofit Coordinator to look after your home and be your trusted point of contact start to finish –gathering quotes from contractors, managing work and installations, and checking the quality of delivery once completed. And the peace of mind you gain from that? It’s priceless.
How to get started
There are three routes into our service, depending on your needs and the direction you’d like to take for your home.
Not sure which route is right for you? Get in touch and our team can help advise you.
Online Plan Builder
(Free)
If you’re curious about the current energy performance of your home but not quite ready to commit to starting your home retrofit process, we’d recommend checking out our free Plan Builder.
Simply put your postcode and the online tool will tell you everything you need to know about the current energy performance of your home, as well as suggesting measures you could take to improve energy efficiency. You can then submit your plan to our team if you wish to move forward.
Remote Assessment and Whole House Plan (£75)
When you register your home you’ll be asked if you’d like a remote or onsite assessment. For remote assessments, we use existing data sources (EPC, floorplans) alongside a 1 hour phone call with you to fill in any gaps. We’ll then produce a reduced Whole House Plan.
If you choose to go ahead with any measures, you will still need to have an on-site assessment, paying the balance of £100.
Onsite Assessment and Whole House Plan (£175)
If you choose an onsite assessment when registering, one of our trained Retrofit Coordinators will contact you to book a time for your onsite home assessment, which can take up to 3 hours.
We’ll use the information gathered to produce a bespoke Whole House Plan, detailing the recommended measures to improve energy efficiency. This will include any particular needs we’ve already discussed with you.
Is Cosy Homes right for your home?
Not sure if the Cosy Homes Oxfordshire service is right for you? Read our blog post, covering more about the types of homes and homeowners that the service will work for, as well as other routes to retrofit if it doesn’t sound right for you.
