Energy Saving Tips

E.P.C ratings will cost your property marketability and sale value.

House E.P.C ratings are now more scrutinised than ever by Prospective homebuyers. They are evaluating the ongoing expense of heat loss associated with properties very carefully. Take this as an example:

  • 3 bedroom Property (A) has an E.P.C rating of an ‘E’
  • 3 bedroom Property (B) has an E.P.C rating of an ‘C’

If your perspective buyer were looking to live in the property for 10 years there would be multiple £1000’s to be saved over this term if they decided on property (B). The money they would lose in energy bills over this term on property (A) would most definitely be viewed as an ongoing expenditure. In face of this, the time, money and unknowns involved in putting right the energy performance of the property they would most likely decide to buy elsewhere or maybe make a deal!

What to consider when raising the general thermal efficiency of your home

When your property is assessed for an E.P.C rating they will consider several factors that combine to create your overall rating. Energy saving lightbulbs, boilers, type of fuel used for heating and general heat retention of your home. Heat retention is a huge factor to consider. If you investing the energy into heat, you want to keep as much of it as you can inside! and this is where we can help.

  • Do you have loft insulation? Does it need to be improved?
  • Old cladding with no cavity wall?
  • How old are your windows? (newer windows have lower U-values)
  • Cold spots due to old soffit board ventilation

External Insulation:


Properties with Traditional wood / UPVC and tile hung cladding has no cavity wall behind it? This offers no real thermal efficiency. With no cavity within the wall space of this area your walls are haemorrhaging warmth at large cost to you and the planet. It also leaves your internal wall spaces susceptible to dampness, as well as cold which can lead to more problems. With energy prices skyrocketing it is now more important than ever to ensure your home is as energy efficient as possible. We install a breathable water membrane and a layer of thermal insulating material ‘CELOTEX’ between your exterior wall and cladding to keep you warm in the cold winter months and limit the amount of thermal escape through the walls. A simple addition that will save you money! We replace your dated cladding with tough Hardie Plank VL cement fibreboard, which is robust, fire resistant, creates instant curb appeal and comes with a 20 year guarantee!

Celotex PIR Insulation Board

We only use Celotex GA4050. The market leading Foil faced polyurethane insulation board for excellent thermal performance and service life in sealed cavity air spaces. BBA certified R-Value of 0.44!

Loft Insulation

Heat rises! 25% of all home heat is loft through the roof. If you haven’t done it already, loft insulation is probably the easiest and most energy efficient return on investment. Even if you have current loft insulation you can still make your home more energy efficient by increasing the amount to the current recommended thickness is 270mm. Back in Nov 2021 ‘Which?’ stated that a simple loft installation could bring down your heating bills by up to £315 per year!

As well as thermal performance we will also discuss vapour control and air tightness.

There are 4 types of loft insulation to consider:

  • Mineral / rockwool Wool Blanket insulation (most popular)
  • Loose fill (lightweight loose granules poured between joists)
  • PIR Insulation Boards (best performance solid boards)
  • Blown Fibre-Spray Foam Insulation (generally problematic)

Which loft insulation is best?

PIR boards offer the highest thermal efficiency possible but is more expensive and will take longer to prepare and install than rock wool. Loose fill insulation can come as fibreglass, cellulose and rockwool but can lose its thermal performance over time, is susceptible to absorption of water (can damage the structure of your joists) and prone to issues with pests. Spray foam insulation is quite expensive, air circulation is severely restricted which can lead to condensation and ultimately rot. Also when your roof needs to be surveyed for any reason the surveyor cannot inspect the eve areas as the spray foam can’t easily be removed. For these reasons mortgage lenders really have a problem with spray foam.

Loft space ventilation

It’s a much better option to insulate the floor of the loft (not the eves). There will be less area for your system to heat and it allows for ventilation of the loft space above…which is important! Without ventilation your roof will sweat (condensation) which will then create rot and/or fungus issues which will in turn eventually contribute towards structural issues.

We only combine the use of mineral wool and PIR insulation boards when installing loft insulation depending on clients priorities and/or what’s needed on any given install.

Our Celotex insulation boards will offer much better efficiency compared to rockwool but is more costly and takes a little more time to install. Also consider for us to add a hard layer on top of your insulation to keep your loft usable and avoid ‘wind wash’, info below.

You can still use your loft as storage!

Your roof space is important for storage. In some cases, the recommended 270mm insulation material is too thick to be placed over the floor joists but we can insulate between the joists with mineral wool/ solid boards and then add a solid insulation board on top of the joists meaning your loft will still have a very usable floor! There is a 2nd benefit with a solid barrier over your insulation. Without it, in a vented roof space ‘Wind wash’ (where the air moving over the top of the insulation from your roof reduces the thermal efficiency of the insulation by drawing heat out of it.) will occur.

Vapour control

So IF you currently have no ventilation in your roof space and for whatever reason you decide to keep it that way, we would definitely urge you to reconsider. But if not, you really should be thinking about adding a vapour barrier between the insulation in the loft floor space and the rest of the house below otherwise all that moisture will be sitting in the stagnant loft space with nowhere to go, causing potential havoc. The question that arises now is ‘what happens to all the moisture that can’t rise up?’. That moisture trapped in the main property space that can also cause problems. There are examples where peoples roof floor joists have rotted as moisture rises and sits where there is nowhere else to travel. Your walls should be able to transmit and receive moisture to some extent but Ideally you need your whole house to be able to breath moisture readily.

Cold spots

You may jump through all the hoops and tick all the boxes that the E.P.C inspector throughs at you in relation to keeping the house thermally efficient but there are hidden areas that even the E.P.C assessor will not be able to pick up that can dramatically improve your houses heat retension!

Old UPVC windows and doors

Gradually over time (since 1965) the government have been slowly and steadily increasing the regulations on what windows and doors are legally allowed to be installed. The ‘thermal transmittance’ of windows and doors are measured in units of W/m2K and is shown in a product as a U-Value. The lower the U Value a window or door is, the better. As of Summer 2023, the combined U-Value for a window and frame to be fitted on a new build will be 1.1 and 1.4 W/m2K for a replacement window. Just for an idea of scale, a standard single glazed window would have an average U-Value of 4.8. If your windows were installed pre 2006 the likelihood is that those windows had a U-value of around 3 when installed. If your windows and doors are a bit tired you may wish to consider replacing them with windows that could be 2x or more efficient.

Old soffit board ventilation

Take a look up at your soffit boards (the part of your guttering system that meets the brickwork). Can you see any vents on them? Those vents are there to help the roof breath but because of the placement on the soffit board it means that you can’t insulate the part of roof that meets the vent. This causes a ‘cold spot’, a place in which heat can easily leave the house. This cold spot will be in place across the whole roofline area of the roof. Current regulations don’t allow installations of this ventilation type these days. We can replace your guttering system with a hidden facia ventilation system that is placed higher up near the tiles so that your loft can now be fully insulated and the cold spot eliminated.