Suggestions for future heating system

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It's a good idea in principle but immensely complicated because of the detailing required at every point where new add-on meets old, mainly in terms of keeping water out, as well as cladding the insulation itself. Effectively building a new house around the old.
Much cheaper and easier to line the inside and add about 100mm to all the external walls, deal with floors and roof.

Yes but that doesn’t solve the aesthetics and causes me more issues….ie ”much easier“ - for starters you haven’t met my missus 😂

…..also, and back to the condensation issue, further INTERNAL insulation will only pull the dew point backwards into the cavity increasing the likelihood of IC……I need to get out my graph paper, get hold of the u-values and do some calcs…… old lecturer would be very proud
I'm not laughing. But I am smiling :) People tend to put insulation at the top of the list, which I agree with, but I think joint top are the simple measures such as a jumper etc, etc.

I have thermal long johns and tops, thick socks etc which I wear throughout winter. The house is usually around 16-17c in winter at peak. When it r occasionally reaches 18-20c we start to get hot under the collar and unconformable, even without the thermal layers. Most people naturally acclimatise to their environment; be it levels of heat, hunger, etc. Heat a house well into the 20s, and over the years you'll feel the cold a lot more as your body resets to the new "normal". I totally accept that different people have different tolerances, but at the same time I think the above holds true.
This is an initial sensable approach and a very good point, people now live in houses that are tropical and travel in cars that are also very warm and assume this is normal wheras many of us grew up in houses with no central heating, open fire or rayburn and had ice on the inside of our bedroom windows, along with travelling in cars that were not warm and cosy. As a kid I travelled in a motorcycle and sidecar with no heating and we went to school in shorts even if the snow was upto our knees so a sensable middle ground needs to be found rather than try and maintain the current high levels of heating. I think we need to accept a certain level of clothing indoors and not shorts and tee shirts. The same can be said of electrical energy usage, rather than complain about rising cost just be more aware and don't leave every light on, although much less usage now with LED but every bit counts. A problem here is technology and standby mode which needs to be addressed, you need a timed supply for Tv's and such that just shuts off overnight.
Lard, we bought an early 70's bungalow of about 100m2 the tail end of 2017. It had no cavity wall insulation and between 25 and 50 mm in the loft. We could not get the place warm.
An 80m2 extension has gone on the side of which 55m2 is workshop/garage, so we now have a 125m2 of living space in the bungalow. Building control unofficially advised me against cavity wall insulation because of potential internal condensation problems, and as the external rendering was so bad we went for external insulation and K Rend finish.
Unfortunately for use the builder used the incorrect insulation that he di d not fit correctly. The wrong K Rend and beads followed and this was not applied correctly. It resulted in 100m2 of mess and a call to the K Rend rep. The only way forward was to remove the lot and start again. The builder has gone bankrupt so I've ended up with a £11K bill to sort it out. The job is now done and looks wonderful. The builder drops me £100/200 through the letter box every couple of weeks, but I'll never see the full amount back. I've also put 350mm of insulation in the loft and now have a very comfortable house and about £90 month gas/electric bill.
I would advise on exterior insulation and K Rend but please contact K Rend directly for a list of approved contractors.


Hi Colin….thanks for this…..I’m guilty of laziness here as I’ve obviously heard of K-rend but not spent anytime looking into it….I’ve sat on the fence too long just over-thinking things.

I think the problem with cavity fill is that there are so many examples of poor results because of the minefield of potential choices out there….as I said, we’ve had zero problems with ours and so my thinking is that we can only improve our situation by doing what you’ve done. I can’t see any practical reason to not do it.

Your place looks really good and I see you changed the concrete tiles too (are those new ones clay?).
Lard, I'd have preferred clay but the tiles are unfortunately concrete. They are Marley Ashmore and give the effect of a double traditional clay tile[from a distance] They are supposed to be suitable for a pitch down to 22.5 degrees but you most be careful. These tiles are brittle and have a weak point in the interlocking design. You can now get a similar visual effect with the Duo Modern that was not available when we did the refurb and will go down to 17.5 degrees. If there is a next time I would look closely at these.

We did an eco build 16 years ago and the GSHP supplying all heating and hot water was part of that. We buy our electricity from an 100% renewable supplier.

The house is two parts - an old oast that was gutted and completely rebuilt and a new part that looks old, but internally is block and beam.

The new part is UFH with the b&b slab acting as thermal store. The old bit has standard emitters which are sized for the lower GSHP water temperature.

Regardless of your eventual heat source, you need to insulate to the very highest standard you can. Just do it.

We hate the whole passive House thing, so we do open windows and doors etc - insane to live in the country and then live in a sealed box!

As we did the GSHP at the same time as the build, it was pretty cheap to install as we had diggers etc. on site - most of the exterior install was done in a day, though it took the lawn two years to recover.

In the 16 years the system has been in, it's given no problems and not missed a beat. Just love it!

Regarding reliability, this is NOT new technology. Heat pumps have been used in Scandinavia and Europe for many decades and the technology is simple and well established. We were in the first 100 domestic installs in the UK, but the system we used was an IVT Green line - IVT are now owned by Bosch, but are an established Swedish company with 10s of 1000s of installations.

The technology is straightforward and not complex - basically a fridge in reverse. It's mostly circulation pumps, filters and motorised valves, all of which are standard parts (Grunfoss etc.) - the only bit that is specific to an HP is the heat exchanger and that's not rocket science either - much the same as a fridge compressor.

It's an extremely mature and well understood technology. The UK is just a bit late to the party - the rest of Europe and North America etc. have been using this stuff for many years.
That is really interesting. Do you have financial info on running cost, size of the property etc. we have a four bed country semi detached that was in 2004 put to the highest level of insulation, but now would be difficult to add insulation. Keeping 99 yr old mother warm was costing 1200 then 1600 and possibly 2000 next year on gas CH and electric. With Electric rising to 20p plus per KWHr and the GSHP having a 3 to 1 conversion that for us would mean changing gas at 3.3 p per KWHr to 7 or 8 p per KWHr. Plus cost of installation etc. I think you could help understanding from your costs. Any thoughts would be helpful. Thanks
I think the problem with cavity fill is that there are so many examples of poor results because of the minefield of potential choices out there
There is a specialist company in the NE that removes this mess when it goes wrong, saw a house where they were working and it looks like it involves removing bricks and tenting but from all accounts they are kept busy.
Our bungalow is just over 200 sqm with 400mm insulation all round. It has electric heaters which 99.9% of the time don't get used. We have a 5KW Morso Squirrel and two desk fans to move the warmth as required and we burn about 40x25kg bags of coal a year, £8 a bag for smokeless. Water is an electric immersion. I might make my own 1.2mx1.2m solar water heaters at some point connected via a thing called a Solasyphon. A pair of panels linked in series in winter and shunted to parallel in summer I think is how you stop it boiling when hot but still being useful in the winter, at ground level too no fiddling with roof tile malarky.
I've planted about 1800 willow shrubs not trees the initial few from Grow Your Own Firewood |
As shrubs these won't get bigger than my forearm so no big heavy logs, 1m spacing one way, 1.5m the other so don't take up acres and acres. We're now at the end of year 3, a few died, a few got blown over, most are now 4m tall and thickening up, first harvest is supposed to be year seven starting a five year cycle, so a fifth of them cut. They I hope will last twenty years and I will have copiced alder ready before the end of that, again, not a massive area. Coppicing giving a controllable log size suitable for me being an old codger. Willow is of course not the best firewood, but I hope better than coal, better than a big electric bill, better than being cold. It may need a physically bigger stove to fit the longer but lower quality logs for the same heat output we have now.
One advantage of a rocket stove is you have one or two quick hot burns of the kind of sticks left over after harvesting my willow, they are not for big logs I believe?

One construction site I spent some time on a few years ago was a shiny new techno building for Cambridge Uni. All heat was supposed to come from boreholes, all the ground investigation said it was suitable but the man doing the drilling spent about ten times as long drilling many more holes than planned because the water could be pumped up but refused to go down again. They gave up which meant a retro not as suitable/eco design for heating was needed. Mucho red faces.

Our house before last was an old thatched cottage with oil heating, very comfy. We moved to a new uber insulated similarly sized house with a concrete floor slab housing the underfloor heating and an air source heat pump. That kept shutting down (SE UK) saying it had frozen up but clearly hadn't. By the time you discovered it was off it took a day or more to heat the floor again, if the error code was one you could override yourself. The basic mechanics may be simple but the control box required a laptop and their dongle. The electric bill was a fair bit more than the thatched house oil bill, similarly sized buildings.

This current new house was classed very poorly in the house purchase eco survey (EPC?) because despite mega insulation the electric heaters were described as shockingly bad. We were advised to improve our house "efficiency" we should install electric solar panels or a wind turbine. The domestic turbine closest to here had it's blades blown off.
There is some talk that obtaining a mortage may be the trick to force people to get an air source heat pump, so despite how well I think our house works as it is we may have to install a heat pump if/when we sell.
Also, far infra red heaters heat you rather than the room and might be nice aimed at you in a workshop or cold room as an idea?
In terms of electric, just bear in mind as soon as we all get thumped into buying electric cars tye government will have to ramp up electricity prices to eyewatering levels to pay for the loss of petrol and diesel tax.... and they'll base it on the extra estimated electricty usage of the cars, not on the overall gain of raising electric prices, so we'll all loose out even more 🙃😆
Not that im a pessimist, honest
Go with a log burner
I have a Dowling multi fuel in a rather small living room with six inch insulated ducting and an in line fan in the roof going to the main bedroom and the kitchen. Works brilliantly.
That's a canny idea Phil as our woodburner often throws out too much heat for our lounge, even on tick over, and it soon gets uncomfortably warm so I'm now thinking how I can extract some heat into adjoining cooler rooms.
I had an Xpelair six inch ceiling fan running it, but the bearings went in a couple of months. I have a six inch Manrose in line fan now which has a higher throughput and is also up in the roof so quieter. I thought about it and turned wooden "halos" to go on the ceiling to tidy up open holes, getting rid of the mesh grids as they only obstruct the airflow. £70 odd for the fan, £30 ish for the ducting and maybe £20 for the other fittings.
Hah! It's currently with Bulb at around 23p /kWh day and 14p/kWh night, but Bulb are a bit shaky and equivalents, like Octopus, are even more expensive. A year ago it was 13p/kWh daytime.

So, using a heat pump that has a COP of around 3.5 (which ours is) that means for every kW we put in from the grid, we get 3.5kW of heat in the house, courtesy of the sun.

Can't ask more, really.
Weve just been moved to Octopus,,received an email today that reveals our standing charges alone will be £180 p/year!!
Try living in a grade two listed cottage with a council who thinks looks and heritage is more important than practicalities, won’t even allow us double glazing and I’m talking bespoke mega expensive joiner made thin profiles so as not to upset the public from twenty meters away. The oil system we have works fine and with the wood burners coming into winter it’s toastey but the heat we lose through the windows is scandalous but eh it’s heritage so it takes precedence