Floor Insulation (How Thick) for EPC Cert

Hello, I have a property which I want to improve its floor insulation. Its a ground floor flat and its a concrete floor. Mr EPC said last time around that “Floor insulation (solid floor)” should be insulated and this will increase my SAP rating. I’m concerned that raising the floor height wits going foul doors etc meaning there will be some admin to achieve his. Now I am minded to do this however what I am trying to research is

  1. how thick should the insulation be
  2. Is there such a thing as an “accredited” floor insulation, or a wrong insulation material
  3. Once its installed, its going to be tucked below underlay 7 carpet, how will Mr EPC seem my good work and aware me my new rating ?

My thought is I am more than capable of removing carpet, flopping down some insulation, fix it down and re fit the carpet. This does not have to cost 1000s to have a fitter come and do it?

Cant anyone lend me some advice as regardless based on their experiences?

I am a builder and I sell insulation. Forget insul on top of conc Waste of time unless 100mm thick . Dig floor up and reconcrete?

I suspect Colin3 is right that replacing the whole floor will be the only way to get sufficient insulation to make a meaningful effect on EPC rating. Will Mr EPC not advise?

when on a new build it is possible to offset insufficient insulation in one part of the job by increasing it in e g the roof. not knowing what your place is like ,only you can determine that

Like EICR an EPC is also a total lottery. The different outcomes depending on the inspector can be miles apart. Worth getting other opinions in my opinion.

If the carpet needs replacing in any case, one of the best underlays is the best for sound and heat insulation. Compare their heat insulation ratings somehow. Otherwise, wall, attic, roof and window insulation is more cost effective and visible to an assessor.

Thanks, yes I think the problem I am grappling with is what am I asking a trade to do, to increase my SAP points on my EPC. I think i am asking about “Retrofitting solid floor insulation”. The concept is to Remove the Sand and cement screed to reach the concrete slab.
Then fit some insulation board and then either pour a shallow sand and cement screed or some Gyvlon liquid screed. This link has some info and case study paper to download explaining how the required u-value.

Articles and Advice | Insulation | Kingspan | Great Britain

To be honest, in a 25 year investment the cost of 6-k does not bother me. I just want to know if this is the correct thing which will result in the required SAP rating.

I contacted Mr EPC as their details are on the online EPC. It was done a year ago and no changed since then. He did come back to me in regards to the storage heaters but did not respond to the floor. He said he can’t comment on individual cases and I expect the nuance there is that I would need to get my own man in and then have him advise.

I think the most frustrating thing is that is entirely open to opinion. And if one over egar peron puts a negative once int the EPC past then each time they copy b paste. I have another property of the same age 1 mile away and its a C grade so I will try my luck at getting it reviewed before I do anything.

First thing i want to do is find out (once i can get back in there / after purchase) if there is wood flooring under the carpet as sell that as enough insulation to increase the sap score to C. Also fit some very good storage heaters. however, i dont want to install the heaters and then remove them to sort the floor out so i am doingmy homework now!

Thanks, yes i will be following this advice!

Ground floor flat, walls, attic, roof, and window insulation does not over apply. The Survey says the windows have good insulation already so i am looking at the ones that the EPC have earmarked as needing improvement.

I was hoping that putting down some insulation (like the silver / gold foil stuff you put down for click flooring) in addition to carpet and underlay would do the trick… however I cannot evidence that this is counted SAP Accredited insulation.

John putting stuff under laminate flooring will not do it. you need a PIR board. but you cannot laminate directly on to it you need 18mm t and g cipboard as a base for laminate or carpet ,on top of pir

trying to get a screed off the concrete is some job That will not be sufficient in any case. The screed is unlikely to be more than 50mm thick…

Hello just to update we got someone to re-evaluate our EPC and it was found that myvery good , very well insulated electric boiler was miss categorised and shown as “poor” under Hot water. When it was corrected and then shown as “average” it upgraded the flat to a D. Then when I swapped the main living froom from a panel to a high efficiently Dimplex storage heater it is now a C.

So my advice is that if your looking at EPCs, look at the features and the ratings. If the Main Heating, Heating Control (best to be temp controlled) and Hot Water. If any of them are Poor investigate why. In my case where it suggested were to improve the property’s energy performance it did not list water heating as an area. Now when I think it about, how can you state something as poor but then not offer a way to make it better? Hence this assessor miss categorised it. Likewise, I now compare my property s epc to others in the block by looking them online and am comparing the feature ratings and nothing the differnce.

My EPC asessor came up and gave me their advice confirming it was a D and charged for that but did not log the certificate. They then said that once I had the work done they would confirm it and publish my final EPC and charged me an extra £26 for the consultancy. 2 weeks later I have my C and am very happy.

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