Please help me understand why our house is so cold

[Guibhyl]

This weekends slightly cold snap has made me remember just how cold our house is in winter. I just don’t understand how or why it is quite so cold and what the hell we can do about it. We haven’t put the heating on yet and most of our house is around 14/15 degrees now.

It’s a 1950s three bed semi. We have all brand new windows and doors throughout, double glazed. We have bay fronted windows in the front lounge and upstairs front bedroom, but these are full bays ie it’s not a normal brick wall with a bay window but rather the bay is almost the entire width of the room if that makes sense. I’ll try to find a picture of a similar one. I know this means that most of the front wall in the bedroom and the lounge are timber framed and thus poorly insulated. About a year ago when we got the window in the bedroom replaced we got them to build the wall under the window out a bit and fill it with lots of insulation. It has made zero difference.

There is insulation in our loft, not to the standard you would have in a new build but a decent amount. We have insulated and draft proofed the loft hatch.

We have been round the house with a thermometer gun thing and can’t see any obvious causes of drafts or anything else.

The bathroom is particularly cold as well as the downstairs hallway again despite having no obvious drafts or anything.

If we put the heating on the house warms up ok, we have a new boiler and the radiators are fine, but the heat disappears within half an hour of it being turned off. In the winter if the thermostat is set to even 16 or 17 then the boiler will be going constantly trying to get it to reach temperature, it will never switch off because the house doesn’t get up that high. Therefore having the heating on for two hours in the morning and two in the evening costs nearly £10 a day. And it’s still freezing.

I’m due DC3 in January and the thought of having to bring a tiny baby home to such a cold house (our room is the coldest) is so depressing. I’m buying as much second hand wool clothing as I can. But I really want to know just why our house is so effing cold. This isn’t something our neighbours seem to struggle with. What have I missed? Any ideas?

Sorry to jump on but am following this with interest- @Palmasailor I have sloping ceilings in first floor rooms. I take it not having loft space directly above means bigger heat loss??

What’s your boiler capacity? Is it big enough for the house? Do you have a seperate radiator and hot water circuits? Do you need to bleed your radiators? Are they big enough for the rooms and do they get and stay properly hot? I imagine you’ve got some cold bridging through the floor going on. What kind of insulation did they use under the kardean, if any?

Yes the heat losses are absolutely colossal through those slopes because you basically have just the plasterboard between you and the outside world (which is the ventilated space behind it which is behind the tiles)

if you give me the square metreage I could do the heat losses for you.

the only way to deal with it is to insulate from below.

I know it's difficult when you are in a semi-detached house but external rendering has helped with our old house. It sounds like a new porch would also help to create an extra layer of insulation.

Ask your neighbours how they cope.

I'm presuming you've tried dehumidifiers and door curtains? The flat we own is notoriously cold and I can't tell you what a difference the dehumidifiers have made. We don't have central heating (it's about a hundred years old and was converted badly - not by us) but use small radiators that we move round, the ones less than 1.5kw are totally ineffective but above that, with door curtains and draft excluders, it's actually quite cosy. We also have lots of throws, wearable blankets etc and wool carpets and rugs on top of the main carpet. We are, however, upstairs.

There's lots of excellent advice already on insulation that might help. Just a thought, is your house north facing by any chance?

Honestly I don't want to join the legion of people diagnosing remotely but you keep insisting no draughts but what do you think a draughty house would be like? It's not like a window open you can feel an actual wind, it's just all the heat disappearing within a short time of turning off the heating.
The fact that your house is freezing but you have no mould or condensation even in the bathroom basically proves that the heat is going out with the air not conducting through anything
You can get Jos sticks which is basically a smoky stick you can go around and find some gaps. Particularly look out for ground floor level IE around the edges of rooms and upstairs ceiling eg puppies and cables going up into the loft.
Good luck, if all else fails a thermal survey might help if you can get a decent qualified surveyor in (rather than an insulation salesperson)

Due to the way that humans work, in terms of regulating our temperature I would look at the humidity (<55%) and consider a dehumidifier.

It may take weeks of drying to make much difference.

I think you have a number of things going on:

1. Concrete floors
2. Poor insulation - particularly the porch, sloping ceilings, bays, and probably the roof.
3. The two main bays on a north/east facing wall (brr).
4. Although you haven't been explicit have you opened up the house internally, to make the fashionable open plan: kitchen/dining/living area. This will be making all of the above feel worse because you can't close and heat smaller spaces.

I second the thermal engineer and suspect your less expensive remedies will be: ramping the insulation and proper interlined curtains across the bays (not cheap because you won't get them made to measure.

The concrete floors are possibly the worst culprit and the most expensive to deal with.

I'd estimate £12k for the insulation and curtains and I'd consider adding an external porch.

Sadly, I think you are expecting a 50s house to provide a 21st century living experience without modifying the fabric of the house to provide it. I bet you didn't use an architect for your alterations.

Ultimately, I think you will have to do a cost benefit analysis against the cost of the modifications and the heating bills and find a middle place.

Where are your radiators? Under the window is the worst place, they should be opposite the windows so make sure they are not covered with curtains or covers.

You can't have too much insulation in your loft so add some.

Do you keep internal doors open or closed? Where is your thermostat?

If you want the whole house the same temperature then doors need to be left open.

@Rewindthefilm

I’ll quote you the numbers so you can get some idea of scale because it’s a huge loss through those areas. They’re the worst in the house.

Heat losses are calculated as follows:

Thermal conductivity of medium in w/mk x sq metres x ( temp delta / thickness of medium in metres ) = heat loss in watts per hour.

If you have a house the same size as OP’s then it’ll have a fairly typical loft space of 36 square metres. If a house that size has sloped Internal ceilings then there are about 18 square metres. Heat losses through that are huge. This is calculated for when it’s zero outside:

0.2 x 18 x ((20-0) / 0.0125) = 5,760 watts an hour or 138 kilowatts in 24 hours.

At 7p a kilowatt hour that’s £9.67 a day plus vat & other losses including boiler inefficiency and pipework losses which I’ve not accounted for. So your total costs will be more than that.

If you compare that to what you’d be losing through the roof area of the same house which has been properly insulated with 270mm of wood:

0.44 x 36 x (( 20-0) / 0.270) = 117 watts an hour or 2.8 kilowatts in 24 hours costing £0.2 in gas.

you're losing nearly 30x through the pitches as opposed to the roof. As I’ve said this is usually the worst single loss in the house.

You can reasonably get the losses through the pitches down to 216 ish watts an hour with some work which is slightly messy but worth it if you’re staying long haul.

Being north facing alone will not explain why it loses heat so quickly - OP said they can get it warm but as soon as heating is off, it is cold without half hour. North facing may gain less warmth from the sun but it doesn't explain a rapid loss of heat from warm levels.

True, but poor insulation would explain it perfectly. A poorly insulated house can't keep heat in. Heat rises, so good quality loft insulation is essential for keeping heat in.

What was the ground floor flooring before you put down laminated wood and was it just as cold then?

I'd echo making sure you have sufficient roof insulation. It needs to be almost 30cm and old insulation eventually settles and sinks so doesn't continue to offer the same benefit. It's the first thing to do when you buy a house if it hasn't been done recently - taking the old insulation out is a messy job so better done before you paint, clean and put new carpets down. We've just finished doing our attic - had to use those loft legs to raise the attic boarding.

Yes this is the issue in our house. In the main rooms the roof tiles come down to the windows with the concrete gutters forming the actual top of the window frame.

Then the bathroom and stairs/landing are flipping freezing as the plasterboard ceiling is straight to roof tiles and no heating in the bathroom
Every summer I forget just how awful the winters are!

Can I just ask here if anybody knows, is thermal paint a con?

Not exactly a con, but it won’t give any discernible benefit.

Get an aga. I have an old Victorian house. Everyone expects it to be cold but it isn’t and I think the aga is a big part of that

Take a look at infrared heaters, they’re more expensive to buy but very efficient to run and are a much nicer heat (think standing in front of a sunny window rather than two currents of warm and cool air mingling).

We have one in the baby’s room that has a thermostat and looks like a mirror, it’s perfect.

lots of responses! Thanks all
some questions I have already answered in earlier posts so I won’t repeat. But new ones:

1. we don’t have any sloping ceilings. However the ceilings above the bay windows do feel extremely cold and it’s my understanding these are just hollow and made of timber so no insulation at all.

1. The downstairs is not fully open plan. We kept doors in partly for warmth and partly for fire safety and also so that we had separate areas we could close off for different activities if needed. So the lounge is the first door on the right off the hallway and can be closed off. It’s a smallish room approx 15 feet by 17 feet. Probably the coldest room in the house other than the master bedroom which is directly above it. It has a bay like shown in my previous picture. Then there is a hallway through to an L-shaped living/dining/kitchen area so this is “open plan” to some extent but there is a door between this are and the hallway and another door then off to the utility. Ironically this is the warmest part of the house despite being the most open plan. I guess partly because the kitchen diner is south facing and gets lots of sunlight. We have two big radiators in this area, the plumber did a heat calculation when he installed them and when he installed the new boiler to work out what would be needed. And yes to the (very judgey) reply we did use an architect for our alterations. As I have mentioned previously there is no problem with the space heating up. Within half an hour of turning on the heating the whole house feels warm. The boiler is a year old, installed by a reputable plumber, the radiators get blazing hot very quickly.

Conclusions so far: the house can be warmed up so no issues with heating or boiler or radiators. Facing north at the front of the house probably doesn’t help as that side gets minimal solar gain. We are losing heat somewhere. Windows and doors are brand new and house is “draught proof” at first glance although some people have suggested there may be draughts coming up from the floors. I don’t think there are though. Downstairs is no floorboards. As mentioned I have previously lived in very old and draughty houses and I do know what it feels like. That is what is so confusing about this place, is that on paper it shouldn’t be the coldest place we’ve lived.

Potential issues: - lack of insulation underneath karndean. There’s nothing under there other than the self levelling stuff they pour before fitting it. Not sure how to fix this - I’m not in a position to rip up £4K of karndean to put insulation underneath. We have a big rug in the living area but I will try putting runners in the hallway so it feels warmer underfoot.

–bay windows in lounge and bedroom. Could try a big curtain across the window, although the window itself doesn’t seem to be the issue but rather the lack of insulation above it. We’ve added insulation below the bedroom window and it’s not made much difference at all. I think we’d need to put it in the top part above the window as well. I could try a curtain that goes right up to the ceiling.

-may need more insulation in loft

I’m not expecting it to be as warm as a new build but I don’t think IABU to expect/want to not freeze when I’ve just had the heating on for two hours!

Also might investigate humidity but lack of mould suggests not. We do get a lot of condensation on the windows if the heating has been on though.

Also not going to be able to get an Aga unfortunately.

Palmasailor - I'm interested in this too! We have a house with sloping ceilings upstairs and it's freezing in winter. What's the work you can have done to fix it, please? I'd like to look into it. Many thanks.

I hang out here because I read the building DIY threads for a lot of reasons, mainly to get a feel for competitors pricing etc.. but insulation is my specialist area, ie it’s what I do in Herts beds berks and bucks.

Basically you have to install a layer of insulation on the underside of the sloped ceilings and then re plaster and re decorate.

sounds simple but you have to do it properly. If you do, you will save 90% on the losses through that area.

You can go more in depth but it then costs a lot more, makes a lot more mess and it takes longer for a return in investment.

In simple terms you line the underside with something like Knauff XPF.

but it has to be done properly.

Interesting, thanks. You cover my area - it would be great if you'd DM me your details.

However the house originally had two separate front doors, one into a sort of integrated porch area and then another into the house itself. The porch was too small to be useful so we knocked through the inside door and the outside door is now our front door if that makes sense. The brick around that area would have originally been part of the porch so maybe it’s not insulated and that’s what is making the hallway so cold? I don’t know if I’ve explained that properly

I bet that's what's causing the cold. I have a porch on the front of my house and as soon as we open that door into the porch all the heat starts to escape. It's fantastic in summer as let's it cools down the house but in winter its absolutely atrocious

Even if windows are double glazed there still seems to be more cold air from them (cooled through the glass) than the walls of the house ime.

@Palmasailor let's just say someone wasn't in a position to insulate their sloping ceiling properly. Would there be anything to be gained/harm done by shoving insulation between the slate roof and plasterboard ceiling? Woolly stuff or those slabs of insulation? Thank you!