I’m trying to install an Air Source Heat Pump in my house. Before installing, I asked my EPC surveyor to do my EPC now (with a gas boiler) and as if I had a heat pump. Unfortunately, this seemed to take my EPC certificate from a C (72) to a D (63). I don’t really want to do this as I’m worried about knocking money off my house if we want to sell it, or not being able to rent it out in future. I’m now trying to think about whether I can add 6 points to my EPC to get back up to the C threshold (69).
I currently have double glazing (rated good), a full stack of loft insulation over most of the roof (rated very good) and cavity wall insulation (rated good). Part of the roof doesn’t have an attic space and is rated average. Every other category is rated good. Does anyone have any suggestions for how to get more points?
The only recommendations on the EPC are floor insulation (expensive, disruptive and only gives 2 points), solar water heating (pretty rare and only two points) and solar PV (expensive).
Due to the rubbishy EPC system it is easy to loose points with efficiency measures but hard to gain them. The better your house the more true that is.
I lost 6 points for a MVHR, considered equal to a constant uncontrolled extract and another 6 for a heat pump, considered electric heating.
All the possible additions to my home add up to less than 12 points. EWI, underfloor insulation, nuclear reactor, etc. The first 2 are on my wish list anyway. I am just optimistic that the EPC system will get upgraded to divide energy use by 3 or more for a heat pump and accept that heat is recovered from an MVHR. I’m not planning to move soon, if ever, but don’t want to leave an energy efficiency mess for my heirs.
I have to agree and disagree with Tim here (as a former DEA). Reduced SAP was not designed with heat pumps in mind, one of several of its pitfalls. However, we took our solid wall Victorian terrace from an E to an A with EWI, IWI, floor and roof insulation as well as solar PV. (please excuse the humble brag, but😇)
In terms of selling, I think it’s still the case that you only need a valid EPC (i.e. performed in the last ten years), rather than needing one that reflects the actual built condition/state at the time of sale.
Insulate your flat roof. Ideally to link with the existing roof insulation to avoid thermal bridging. The EPC does not seem to consider thermal bridging but if a job is done it should be done properly. This can be done from above or below depending on the state of the roof/ceiling and whether remedial work would be required soon anyway. Make up any missing depth below the current ceiling height. That’s a lot of work to get one or maybe 2 points.
Replace any remaining incandescent lights and old type fluorescent tubes with LEDs. One point max and probably not pertinent.
Rip up your ground floor, insert 300mm minimum insulation and make good. Sounds easy like that but isn’t. For EPC points you don’t need that much insulation but if you are doing it you may as well do it properly. My EPC surveyor gave me credit for the 50mm that could be seen through an airbrick. No one in their right mind would go to all that trouble and then not do a proper job.
I have solar thermal and PV, both installed in 2006, before RHI but they paid for themselves long ago. I had to privately import solar thermal parts from The Netherlands, you would have an easier job. Plan the installation in conjunction with the heat pump even if they aren’t done together. Otherwise you risk built in redundancy and the need to replace perfectly good components when phase 2 goes live. As well as energy saving you will not need so many accessory parts, and thus reduce costs, for the combined projects. 2 points.
I’m not sure that I would recommend PV to anyone that has an empty house during the day and a tight budget. If you can set appliances to run when the sun shines then that is anther matter. PV will help support heat pump running costs, the equivalent of having a small gas well under your house to assist your boiler.
The guiding principle of PV is to buy as much as you can afford. The benefits to EPC are justifiably not great as there is least PV in winter, when you need it most. 1 or 2 points, depending on system size.
PV with battery is another matter. FYI, battery = zero points. At least it isn’t negative.
If you have MVHR fit override switches in each extract room and tell the EPC surveyor that it is a manual system. Don’t mention MVHR. 6 points.
The overrides may even be useful at times
Edit: if you have a suspended floor you could consider Q-bot. They can apply multiple coats to build up to Passivhaus grade floor if conditions permit, and the floor doesn’t need lifting.
For technical reasons my house wasn’t suitable. They helpfully said if I carried out remedial work they could proceed but of course I would insulate for myself while doing the remedy!
I have just become aware of the Scottish government’s proposed changes to EPCs. Judging by previous Scottish initiatives England should be in a similar position within the next 10-20 years! (Call me a cynic if you want.)
Great detail @Tim_Gilbert . I’m slightly unsure about isolating extract vents in an MVHR system, as that would unbalance it. Did you have a particular time of year or scenario in mind?
Some recent research has shown EPC values have a higher impact the further north you go, for two main reasons (coolth and population density). But a property’s thermal performance might be becoming more important…
I’m afraid I didn’t make myself clear. I am not proposing any isolation of vents. Most, or maybe all, MVHR systems have optional hardware to boost airflow. Using the app with mine I can choose from 10 minutes to several hours. There are also manual override switches available, which I don’t have, for when an extra boost is needed for a quick removal of humidity or smells. If each room with an extract has a boost switch then it could be operated almost as an on demand ventilation system. In practice hopefully not, but what the householder gets up to when alone is not included in the survey.
I did consider saying and doing nothing and hoping the system isn’t noticed. If it is noticed you could say it’s en extract with a humidistat but that wouldn’t enable the system for smells.
My own system has a gradual auto increase function as the average extracted air humidity increases. Smells with transient causes disappear in a few minutes. I only need to boost if there is an ongoing source of smells (cooking dried fish comes to mind) or for purge ventilation overnight in excessively hot weather.
Having sent over £150k retro fitting a rural cottage, I was gobsmaked to find it only went up from and EPC F to and E… Underfloor insulation is probably the best way to get bang for your buck. I sort of wish we had done that, but there were other prioiities (Iike fixing the roof, but at least got Solar PV added to that!). If the rules state that you need a D or above to rent out then I’ll have to look at the underfloor insulation again - or install a wind turbine, which was the other helpful suggestion from the EPC report…
I take it you live in isolation on top of a mountain.
The rules for EPCs change, so your F to E may not be comparing like for like.
If you are EPC climbing you need a different retrofit plan than if you are trying to improve your thermal efficiency. There is an overlap but not as much as you might imagine.
To improve your EPC you need to do the list on the end of the certificate and ask the surveyor for an additional list in EPC points order. Many landlords have got this down to a fine art, putting the least possible money into the job.
I’d confirm with the DEA prior to engaging them that they are willing to add the evidence needed for any non-standard U-value. It’s not difficult or time consuming to do in EPC software but some DEAs are of the “drive by” variety and just want to get in, out and submit as quickly as possible. A £35 price is usually a sign of that.
That’s true, although actual drive bys are hopefully a thing of the past.
When I was arranging my EPC I contacted several people and specified I was after a meaningful survey from which real improvements could be planned. I also outlined the work I had done and the evidence I had available. I had responses from 2, one of which subsequently ghosted me. I was happy with the one I engaged and the price paid (£120).
Hi everyone, my EPC surveyor doesn’t believe Aerotherm plastering would get us any points. However, he did propose a solution. It turns out that if you add specific models of heat pump into the calculation, then you get more points. For my house under the current regulations, adding a generic ASHP (where you don’t enter the brand) moves me all the way down to 60 (from 72), however adding a Samsung 8kW monobloc pushes me up to 75 (i.e. still a C). So this is great, and I should be able to get one!