Electric Heaters in new build home and lack of insulation

Panda126

Hi everyone,
We bought a new build 'eco' home this year and it's our first winter here.(4bed)
It was supposed to be a passive house with EPC rating A, however we are unable to keep the warmth inside.
We have electric radiators (dimplex brand).
There's no chance we would be able to keep the house warm. We have 11-13 degrees inside. We try to have the heating on for a few hours, barely reaching the temperature of 18 degrees, but the moment we turn it off it's gone to what it was before within TWO hours! If we keep it for longer we pay £20+ a day and it's only two of us, we don't use much of electricity except heating. Currently we spend all day in one room where we try to keep temperature around 19 degrees, with all the doors locked and when we turn it off it's dropping 0.5C every 20 minutes (we calculated it today).
Would that be because we have electric heating or the insulation wasn't done properly? Does anyone have any experience with electric heating? 
We have built in (cold) garage and we're wondering if that might be the issue as well. Thank you for any advice! 

Netexporter

Heat is heat, wherever it comes from. You call it a Passivhaus, were you issued with certification to that effect? Which part of the country are you in? It's pretty cold in most places at the moment.

Panda126

Yes we have EPC rating A (92 points) and we live in south Wales 

QrizB

£20 of electricity a day is about 70kWh at current prices, which is as more energy than the gas I'm using to heat my 50s semi (no EPC but I'd guess D or thereabouts).

It would run a 3kW heater continuously, 24/7.

It definitely doesn't sound right for an EPC A newbuild.

Can you get into the loft? How much insulation do you have?

The heater in the one room you're heating. You say it's made by Dimplex, but what's the model number?

Netexporter

I live in a 1980 bungalow in Mid Wales, with a G EPC, and I'm toasty on two buckets of logs a day. Sounds like there is something amiss.

Yes we have EPC rating A (92 points) and we live in south Wales

A proper Passivhaus would have a higher score than that.

theoretica

Assuming you have neighbours in similar houses, how are they finding the heating?  That would help narrow down if it is something about your specific house that isn't correct, or the design, or something you haven't thought of.

But if it is the *house* that is insulated, then that won't necessarily mean that the one room you are heating is insulated from the rest of the house and the other cold rooms. 

Reed_Richards

According to Passive House requirement:

1. The Space Heating Energy Demand is not to exceed 15 kWh per square meter of net living space (treated floor area) per year or 10 W per square meter peak demand.

You don't say how many square meters of floor area you have and you must be experiencing near peak demand at the moment.  My floor area is about 170 square meters so I would expect to be having to use 1.7 kW to keep my house warm over the last few days if I lived in a Passive House.  That's a 2 KW heater on for 85% of the time.

Panda126

QrizB said:

£20 of electricity a day is about 70kWh at current prices, which is as more energy than the gas I'm using to heat my 50s semi (no EPC but I'd guess D or thereabouts).

It would run a 3kW heater continuously, 24/7.

It definitely doesn't sound right for an EPC A newbuild.

Can you get into the loft? How much insulation do you have?

The heater in the one room you're heating. You say it's made by Dimplex, but what's the model number?

Yes that's correct we used around 70kWh and the house was freezing in the late afternoon, it was 13 degrees except the room we tried to keep warm. We're worried the insulation wasn't done properly I don't know how it's possible for the temperature to drop so quickly and we have all the windows closed, all the vents closed. as for the loft it seems that there's quite a lot of insulation.

Gerry1

Is mains gas available in your area?

Lorian

What temperature was the garage getting down to.

Green_hopeful

Can you borrow a thermal camera to look for warm areas on the outside of your house. Or if not get an electronic thermometer and look for cold areas inside. I think something like this? https://www.amazon.co.uk/Infrared-Thermometer-Helect-Non-contact-Digital/dp/B071NBJJ2Q/ref=asc_df_B071NBJJ2Q/?tag=googshopuk-21&linkCode=df0&hvadid=310864933873&hvpos=&hvnetw=g&hvrand=11121217490895159084&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9046216&hvtargid=pla-349733104962&psc=1&mcid=60b880dce30136dca06e94af04e7ffe4 I have a thermometer and I can sweep across the room and see where the colder areas are. That would focus your search. 

We have friends who live in a eco house on an estate and they have had no end of problems. I think it’s a lovely idea to have a eco house but sometimes developers don’t come up to scratch.