Loft Insulation

On this page you can read about:

1 – Benefits of Loft Insulation

2 – Loft Insulation Grants

3 – How to Fit Loft Insulation

4- Pros and Cons of DIY vs Professionally Insalled Loft Inslulation


1 – Benefits of Loft Insulation

25% of the heat lost from your house every year escapes through the roof. If everybody in the UK properly insulated their loft to 270mm, we would save nearly £500 million on wasted energy each year.

Insulating your home reduces wasted heat, cuts your heating bills and reduces carbon emissions.    

Installing loft insulation is an easier job than cavity wall insulation and could cut your energy bills by up to £175 a year. The payback time is also very quick, ensuring that you make your money back fast and then see the savings.  As loft insulation lasts for over 40 years it will pay for itself over and over again in that time.

The main benefits include:

  • reduce gas & electricity bills
  • reduce your home’s carbon footprint
  • keep your house warmer in winter
  • keep your house cooler in summer
  • improve your home’s energy efficiency rating
  • increase the value of your home

Loft insulation for a typical three-bedroomed, semi-detached house with gas central heating starts at around £50 for DIY installation, and could take less than a year to pay for itself through the savings you’ll make on your heating bills.

 Loft insulation costs and savings

The table below ( from the Energy Savings Trust) shows the approximate costs and savings you can expect when insulating a loft in your home.

Loft insulation(0 to 270mm) Loft insulation(100 to 270mm)
Approximate saving per year Up to £175 £25
Installation cost £100 to £350 £100 to £350
Time taken to pay for itself Up to two years From four years
DIY cost £50 to £350 £50 to £350
Time taken to pay for itself  Up to two years From two years
Carbon dioxide saving per year Around 720kg  Around 110kg
These are estimates based on insulating a gas-heated, semi-detached home with three bedrooms, showing savings when you insulate an uninsulated loft, and when you top up 100mm of insulation to 270mm. (The recommended depth for mineral wool insulation is 270mm but other materials need different depths.)

The figures above should be used as a guide only as they may not take into consideration the recent changes in gas an oil prices across the UK.

Improve your home’s energy-efficiency ratings

When you sell your home you will need to get an Energy Performance Certificate (EPC).  These help the buyer to see how efficient your home is – your house will be given a rating from A-G.

‘A’ represents the most energy-efficient properties and ‘G’ the worst. The EPC will also advise you on what home improvements would be best to help you cut carbon emissions and fuel bills.

If you’re selling a property in England or Wales, you must get an EPC. You’ll also need an EPC if you’re a landlord looking to market a property for rent – like buyers, prospective tenants can ask to view this before they sign a rental contract.

Fitting loft insulation is a great way to improve your home’s energy-efficiency rating. If your house isn’t insulated, the EPC will recommend it be brought up to current standards for maximum efficiency.

Even if you have loft insulation but it’s considered to be too old, inadequate or inefficient, the EPC may also recommend necessary improvements.


2 – Loft Insulation Grants

Absolutely everybody is eligible for a grant of some kind from the government for loft insulation.

The list below shows the benefits that allow you to qualify for FREE loft insulation.   If you are aged 70 or over you do NOT need to be on any benefits – you will be able get loft insulation installed completely FREE.

Even if you are NOT over 70 on on benefits you WILL still get a partial grant of 50-70% of the total cost as this is for everybody.

You should be eligible for a 100% grant if you receive:

  • Attendance Allowance
  • Child Tax Credit (annual income of £16,190 or less)
  • Council Tax Credit (which must include a disability premium)
  • Disability Living Allowance
  • Disability Pension
  • Housing Benefit (which must include a disability premium)
  • Income Support (which must include a disability premium)
  • Income-based Job Seekers Allowance
  • State Pension Credit
  • War Disablement Pension (which must include a mobility supplement or Constant Attendance Allowance)
  • Industrial Injuries Disablement Benefit (which must include a mobility supplement or Constant Attendance Allowance)
  • Working Family Tax Credit (annual income of £16,190 or less)
PLEASE NOTE – Free loft insulation is generally only given if there is 60mm or less of loft insulation already in the loft.  If you have over 60mm of loft insulation you may only be eligible for a partially grant so the loft insulation top-up will only be discounted (not free) – Even if you are over 70 or on benefits.

Most energy suppliers, such as British Gas, Npower, ED, Eon, Scottish Power and SSE, offer discounted loft insulation that could cost as little as £100, including installation. This could be even cheaper (from £1/m2) if you fit the insulation yourself. Check local DIY shops for their latest DIY offers, too.


3 – How to Fit Loft Insulation

The recommended thickness for any loft insulation is 270mm. The first thing to do is check whether you have any insulation at all in your loft and if you do, how much. You might already have some insulation in your loft but if it falls short of the recommended 270mm, you could make further savings on your energy bills by topping it up.

Before installing any type of loft insulation

It is important to prepare the next 3 steps before insulating any loft -

  1. It is always best to clear your loft to help avoid any accidents and so that you can insulate the loft completely and properly.  If you’re getting a professional loft insulation installer to complete the work for you, you’ll almost always need to completely clear your loft before they arrive.
  2. Pipework and tanks in the loft should also be insulated correctly, as less heat will be escaping into the loft and protecting pipes from freezing.
  3. Wiring needs to be dealt with safely. Wires should be kept above the insulation if possible but not stretched if they don’t comfortably reach. An electrician will be able to re-route any problematic wiring.  As insulation material is non-flammable the insulation can be laid over wiring – this is what many professional installers will do.

If in doubt  - Insulation must be installed following the manufacturer’s instructions to achieve the full benefit. If you’re unsure about any aspect of insulating your loft, you should contact a professional insulation fitter.

Fitting blanket insulation

Blanket insulation is the most common loft insulation found as it is sold in rolls and is easy to install yourself

Rolls of blanket insulation come in various widths to allow you to make the total depth of insulation up to 270mm – so if you have 0mm, 50mm, 100mm or 150mm already in your loft you will be able to top it up to the recommended depth.

Start by measuring the depth of insulation that you already have in the loft and buy rolls of insulation of a thickness that will make the total depth between 270 and 300mm once all the insulation is laid.

Ideally the first layer should fit neatly between the joists. Don’t stretch or tear blanket insulation – use scissors if it needs to be cut to fit.

Unroll the insulation blanket and lay it flat between loft joists. Your joists will be no higher than 100mm so you will then need to add a second layer of blanket insulation across both the joists and the lower layer of insulation. Be careful not to squash the insulation down.

Please note that unless you only partially insulate your loft or use ‘Loft Storage Stilts’ you will not be able to store your belongings in the loft after it is insulated to 270mm.

Fitting loose-fill insulation

Loose-fill insulation is best for lofts with in inaccessible spaces that make using rolled insulation difficult.

Loose-fill loft insulation is made from light materials, such as cork granules or even recycled newspaper, which is evenly spread in the gaps between the joists.

Work out the floor space in square metres – you’ll need approximately 200 litres of material to cover each square metre to a depth of 200mm.

Before laying the material, ensure the space between the joists is relatively dust-free and that the depth of the joists is sufficient to hold an acceptable level of loose fill insulation.

The material should be poured between the joists in the roof space, ensuring there are no cracks or holes in the ceiling. Brush or rake between the joists to ensure the fill is level.

If you’re not fitting boarding over the loose fill, check the level of the material during winter months as high winds can unsettle loose fill insulation and blow it around the roof space.

To insulate a loft hatch, it’s best to use blanket material held in place by plastic or an old sheet.

4 – Pros and Cons of DIY vs Professionally Fitted Insulation

Pros -

  • A professional installer will have access to your government grant and be an expert in fitting insulation.
  • They will have knowledge of potential issues that can come from poor loft insulation such as condensation problems, tanks and pipes freezing and avoiding heat loss through the hatch.
  • They will ensure that the insulation is fitted properly and take measures to avoid all of these problems.
  • This is the best option for those that are low on time or DIY skills and want peace of mind that the job is done properly.
  • It will all be done in a couple of hours.

Cons -

  • Most companies will require you to completely empty your loft of all your belongings before fitting.
  • You can expect to pay around £170-£220 for full loft insulation of any size loft.

DIY insulation

Pros -

  • Can be slightly cheaper than professional installation as the grants are also placed on the discounted loft insulation.
  • You do not have to completely empty your loft.
  • You can do it in your own time.
  • You can expect to pay anything from £50-£350 for that materials to insulate your loft depending on it’s size.

Cons -

  • Time consuming, uncomfortable and dirty job.
  • Not recommended for anyone unless they are confident of the proper way to lay the insulation.
  • It is important to also insulate all the pipes and tanks, to leave gaps for ventilation, to purchase and use the appropriate protective clothing, to draft proof the loft hatch, to correctly approach spot-lights etc – all factors that many do not realise and if not considered will lead to poor efficiency (lower savings on your bills) and perhaps even damage to the loft.





Buy Loft Storage Stilts from B&Q now.

What a sensible idea! We are currently facing the problem of insulating a loft that is full of memorabilia.... ;) These stilts seem to be the answer! — Dianne, Birmingham

Brilliant idea! I didn't have any storage space in my loft as it was fully insulated but I have just used these stilts and can now use my loft for storage. Thank you!! — Sean, Crawley

Great product - So simple but just what I needed. Well done!! — Joseph, Leicester

I'm so happy this product is now available. I have wanted to get my loft properly insulated for years but did not want to lose the storage space or deal with installing new timber joists. Now I can - thanks! — Sarah, High Wycombe

Loft Storage Stilts are strong!! They can hold over 500kgs each. In fact, structural engineers recommend that you should never store more than 50kgs per meter square in your loft as the joists could buckle. Take care not to overfill your loft!!
Check out the Frequently Asked Questions page for more information on how to best install Loft Stilts. Using larger boards is the most important way of getting the best value for money and creating a larger area using fewer stilts. There are loads more great tips too so be sure to take a look.
Diall Loft Storage Stilts
Diall Loft Storage Stilts