EPC F, approximate heating costs help!

Fionachippy

Hello,
I wonder if anyone can help.
My parents have had an offer accepted on a house with an EPC F. They are not worried about the rating per se as the house they've just sold is an E with far worse problems (major damp and needs a new roof) so they understand the issue with old houses. They aren't looking to rent any of the new place out. 
They currently have oil heating and an open fire. They never turn the heating on and use only the fire. It's a house of 300 sq metres, with damp, in Cumbria (ie freezing) and they have been perfectly happy with that for 40 years.
They are moving south to north Devon so my partner and myself can live with them (they are 88 and 90, very fit and well). My adult son has recently suffered a minor brain injury and may not be able to return home to Ireland so we need somewhere large.
The new house is over 400 sq meters with I think 15 rooms (some big, some small and cosy), Georgian and despite the apparent lack of insulation (as assumed by EPC), feels dry as a bone and seems sound. Not a crack to be seen.
I've never had to think about heating on this scale before.It's mains gas and two open fires. The top floor (about 5 rooms) has no radiators.

The EPC says the primary energy use for this place is 394 kilowatt hours per sq metre. The house is 420 sq meters. Can anyone explain what that actually means in terms of heating (other than it's a lot..their current place is 300 kw hours). We're planning on being frugal, as per now, and maybe getting a multifuel burner and wouldn't be heating the whole place at the same time, only bits as needed. is it possible to have a very rough idea of what yearly/monthly costs that might mean? i know this is like asking how long is a piece of string but I have no clue. 
Thank you for any pointers (including walk away now, you'll be bankrupt within 6 months). 
Much appreciated, thank you.

anselld

The full EPC should have an estimated energy usage.  It will only be a very rough estimate but it is as good as anyone can give you.  It will also tell you what are the most cost effective improvements to make.

deannagone

Before worrying about heating costs, I'd be getting up in the roof space and seeing if insulation can be put up there as a matter of urgency once you move in.  That will lower your heating costs considerably (I did it in a rental, so can speak from experience). If its Georgian - is it listed (I'd check very carefully) as that may limit your options considerably? I'd also be looking at the condition of the roof in such an old house, checking for ground levels on the outside as well as its suprisingly easy to have soil build up against walls over time (which causes damp, although I appreciate you are saying you can't see any).

You might be able to install secondary glazing as well or even put plastic up at the windows.  I used cling film years ago but now you can get things like window insulation film for the rooms you intend to use the most (see amazon).  If windows do seem drafty, do some googling and see if you can use insulating tape at the windows and doors.  Make the best of what you have basically.

Fionachippy

anselld said:

The full EPC should have an estimated energy usage.  It will only be a very rough estimate but it is as good as anyone can give you.  It will also tell you what are the most cost effective improvements to make.

Thank you, yes, that's the bit I can't understand..dense, I know. 394 kw hours per square metre. I don't know how to translate that into an approximate figure!

silvercar

It is really difficult to predict energy usage.

By moving from Cumbria to Devon you already gain a few degrees of heat without doing anything. By only heating the rooms you need and keeping doors closed, the size of the unused rooms is less important. Without the heating switched on, it doesn't matter how many rooms you have!

The epc isn't going to give you much of a guide - a few led bulbs (working or not) and the numbers improve.

ProDave

"The EPC says the primary energy use for this place is 394 kilowatt hours per sq metre. The house is 420 sq meters."

Simple maths 394 X 420 =165,480kWh per year if you heat the whole house.

With gas at about 13p per kWh that's £21K per year in gas bills.

Obviously a lot less if you don't heat the whole house, can improve it, or the EPC estimate is just plain wrong.

Clearly an old, poorly insulated large house is going to be expensive to heat, but nobody really knows for certain just how expensive.

RAS

Having experience of this sort of house:

Is it listed? As that may affect what you can do to improve the situation.

What is the aspect? Can you use solar gain?

Find a curtain exchange and buy anything that fits, preferably going to the floor if there is no radiator under the window. Develop a routine of closing all the curtains at dusk and you'll cut draughts and gain about 5C.

Also in winter, or after rain, go round in the morning and wipe the condensation off the windows. Wring out the cloths and dry outside if possible. On dry days, ventilate the rooms for 10 minutes.

Get a good thick curtain to close of any corridor or staircase that's not occupied.

Try to dry clothes outside if possible.

Then consider any insulation and draught proofing you can, even as basic as the sausage blocking a draughty door.

If possible, insulate the roof and if you have a crawl space, under the ground floor. And research what you can do to improve the windows. If you can't replace with double -glazed, consider secondary glazing. 

And buy hot-water bottles.

FreeBear

ProDave said:

"The EPC says the primary energy use for this place is 394 kilowatt hours per sq metre. The house is 420 sq meters."

Simple maths 394 X 420 =165,480kWh per year if you heat the whole house.

With gas at about 13p per kWh that's £21K per year in gas bills.

Obviously a lot less if you don't heat the whole house, can improve it, or the EPC estimate is just plain wrong.

Clearly an old, poorly insulated large house is going to be expensive to heat, but nobody really knows for certain just how expensive.

"What is primary energy use ?"

Primary energy use is a measure of the energy required for lighting, heating and hot water in a property. The calculation includes:

• the efficiency of the property’s heating system
• power station efficiency for electricity
• the energy used to produce the fuel and deliver it to the property

Just looked up the EPC for a neighbouring property that is almost the same as mine. The primary energy usage is given as 358KWh per m² a year. At 90m2, this works out at 32220KWh. From other sources, I know they use ~14000-16000KWh of gas to heat the place. The EPC energy usage is a complete joke.

You'd be better off asking the previous owner what the heating bills were for previous years. Some of the comparison web sites scrape usage data from a central database and populate the fields with approximate figures. Can't seem to find one that is currently doing energy comparisons and auto-filling usage.

badger09

WOW that’s a very large house with potentially very large heating bills. 

In addition to what’s already been said, I would ask whether your plan is for all 5 (possibly 4) adults to live mainly communally. If so, then heating & cooking costs should be manageable if you’re all fairly hardy folk. However, if you’ll effectively be living as 2 or 3 separate households in the same large building, I would think long and hard about going ahead with this purchase.