Installing EPC improvements myself — but is it tax deductible?

1. You cannot hire yourself i.e. get a tax deduction for your time as a landlord carrying out the work.
2. The work itself is arguable both ways, I currently have a case where HMRC is trying to deny tax relief for improvements in a CGT claim, they are arguing that they are not improvements. I have had cases in the past where HMRC has contended the opposite in a claim for expenses in an income tax return,

Apologies that I’m not answering your specific questions, but I have the following observations and questions of my own:
What is your current EPC (e.g “D64”)?
How many points do you calculate you’ll improve it by?
Have you communicated with an assessor to gain a better understanding?
As you don’t mention the size of the property, it’s difficult to estimate your investment in this, but you often spend twice your estimate and also take twice the time. A rough guess for the non-labour works involved, to almost all walls, is well into £10k plus. Therefore, is it not wise to leave the project until you establish whether the cost of your works might be capped under the long awaited proposals?
Might you achieve a “C”by having solar panels installed instead(if not too shaded etc) at perhaps £5 or £6K, depending on your location to an extent. You may of course have such improvements in place already.
Although it’s an ideal opportunity to work on an empty property, I’m not sure about it resulting in a return on investment-more a service to your future tenant by reducing their overhead costs.
I am all for us providing our house to be their home, and for that home to perform to all required standards, but we also need to look at the other side of it as to whether such capital expenditure should translate into capital growth, if you are sure it’s a property you want to keep for the long term.
It’s not a crime for landlords to need to be viable in business (even if only one property).Take private landlords out of the equation and the country’s in dire straights.
Best wishes with your works if you go ahead.

It might pay you instead to hire a contractor and just assist in doing some of the easier work which could be done evenings/weekends. (e.g. painting. decorating, making good). The contractor’s labour charges would be tax deductible and your void period could be much shorter especially if the contractor used a team of 2 or 3 workers.

I wish you well with the project, I would just add that in carrying out the works you take photos and keep all invoices because the epc assessor will not just take your word for whats been done, I know this from experience.

Here lies the problem with your idea
One you can’t claim for your labour.
Milage yes but Your time NO
Are you an accredited installed like the 30,000 homes which were fitted with defective insulation both inside and outside under the last scheme ?
The EPC assessment is changing and is much more comprehensive and also expensive.
They want solar panels and hear pumps Not cheap and efficient Gas Combi boilers.
Some ” Insulation works ” have caused major Mould and damp issues
Good luck but for now I am sitting on my hands
If you make a bedroom smaller with internal insulation you may have a Lovely warm room but the HMO team may measure the room size and say it’s now too small to call a bedroom !
6.5m2 or 10.5m2

I too feel I could do this kind of IWI myself, but having looked closely into it, there is a major issue that you can’t mark your own homework. You must get the job properly analysed and specified by someone knowledgeable about building regulations and energy assessment. It would be a disaster to o do all this work and then be told you only get an EPC uplift of a few points because the insulation isn’t thick enough, and/or you haven’t dealt with cold bridges, or there are too many leaks and poorly applied seals, *and* at the same time you have insufficient controlled ventilation to meet building regs. As an amateur I would only do this work under close supervision and a guaranteed EPC outcome for a given spec.
You also don’t mention other insulation opportunities, like LECA lightweight fill in redundant chimneys and under ground-floor floorboards,.You will need a whole-house insulation-ventilation-cooling appraisal and specification and then EPC/building Reg quality validation at the end, otherwise you could be throwing your money down a drain.