UFH Design and Zoning - Self Build

[Adrian Walker]

26 minutes ago, Adsibob said:

This is just not true. At least not in an airtight house. It also makes no sense to have sleeping quarters the same temp as say, your lounge and kitchen. Sleeping quarters are more comfortable at 18C (+/- 1C), whereas that would be far too cold for a living room, dining roo, bathroom or kitchen.

So how do you keep rooms at different temperatures? Perhaps with an upside-down house? 

[Adsibob]

12 minutes ago, Adrian Walker said:

So how do you keep rooms at different temperatures? Perhaps with an upside-down house? 

Don’t install heating in the bedrooms, as @ProDavealluded to.

 

Ventilate the rooms you want cooler.

 

Time you heating use intelligently. 

[PNAmble]

29 minutes ago, Adrian Walker said:

Perhaps with an upside-down house?

We are in the process of building an upside down house - including the master suite upstairs.   3 other bedrooms downstairs.  PH u values and airtightness etc.   no heating in bedrooms except TRs in en-suites. ASHP and low temp radiators (assuming 40/35 degree flow rate) In living areas upstairs and in hallway downstairs. 
 

🤞we got our calcs and thermal modelling / heat loss correct.  

[Lofty718]

It depends how your house is heated, a weather compensated low flow temperature system is a different type of heating to what most are used to and having all of the rooms at the same temperature is not an issue, it's much better and more comfortable.

[JohnMo]

9 hours ago, Adsibob said:

Don’t install heating in the bedrooms, as @ProDavealluded to.

 

Ventilate the rooms you want cooler.

 

Time you heating use intelligently. 

Every other house we have owned, except this one, the bedroom window has remained open all year (except a couple of very cold nights) and radiators switched off. That includes a very old poorly insulated, and brand new at the time houses.

 

10 hours ago, Adrian Walker said:

10 hours ago, Adsibob said:

for a living room, dining roo, bathroom or kitchen.

So how do you keep rooms at different temperatures

Current house everything is on one floor, bedrooms are generally cooler/colder, we do this by putting less heat into those rooms and closing the room door. If we want the room the same temp as the rest of the house we open the door for 30 minutes.

 

And we still have everything on single zone. You make any room, any temperature you want, with flow balancing. More flow, smaller deltaT across the emitter equals higher output.

[iMCaan]

22 hours ago, joth said:

But "Normal" does not necessarily mean good (or even legal for that matter). What is the EPC of that other build, and how much are they actually spending on heating?

 

The advice on this forum is generally predicated on the assumption that if you're building your own house, you want to do a (very) good job of it. Much better than BR minimum. It's what is called the "fabric first" approach. Unless the fabric of the building is good, all the other advice here built on it is not likely to work out so well.

You either need to change tact to build a high quality building, concentrating on thermal bridge free insulation, airtightness and actively managed ventilation, or stick to normal build with the normal received wisdom on heating. If going the latter route it would mean keep the FF UFH, keeping the zoning, keep with the gas boiler.

 

 

What U-value does your SAP report say this is? How about the floors and roof? Have you had anyone draw up a room by room heat loss calculation? Or you can do this yourself using the calculator on here

 

 

 

I don't know much details about the the other build.

 

Just shows how inexperienced I am. If I had even a little bit of advice about putting in more thicker insulation in cavity I would have. I remember asking the builder about putting in 75mm insulation in cavity wall but he said it's usually 50mm and you need 50mm void for air circulation. Therefore, I went with 50mm Kingspan.

 

The SAP is 52 pages of calculations and numbers, too much jargon. I don't think I'll understand any.

 

I don't think I can do much about the cavity wall insulation now. Perhaps I can use insulated plasterboard? 

 

On the ground floor, we planned 100mm insulation with UFH. I have read people putting in 200mm insulation but I can't do that due to FFL.

First floor to have 25mm insulation with UFH.

 

In regards to roof/attic room insulation, I have planned 200mm insulation between joists, 100mm and 50mm between trusses and then plasterboard.

 

 

 

 

 

 

[Conor]

6 minutes ago, iMCaan said:

 

I don't know much details about the the other build.

 

Just shows how inexperienced I am. If I had even a little bit of advice about putting in more thicker insulation in cavity I would have. I remember asking the builder about putting in 75mm insulation in cavity wall but he said it's usually 50mm and you need 50mm void for air circulation. Therefore, I went with 50mm Kingspan.

 

The SAP is 52 pages of calculations and numbers, too much jargon. I don't think I'll understand any.

 

I don't think I can do much about the cavity wall insulation now. Perhaps I can use insulated plasterboard? 

 

On the ground floor, we planned 100mm insulation with UFH. I have read people putting in 200mm insulation but I can't do that due to FFL.

First floor to have 25mm insulation with UFH.

 

In regards to roof/attic room insulation, I have planned 200mm insulation between joists, 100mm and 50mm between trusses and then plasterboard.

 

 

 

 

 

 

Your builder and architect need to be taken round the back and beaten up. You're going to fail your as built SAP and won't get building control signoff or a mortgage. Drawing seems shows 100mm full fill insualtion in the cavity, your SAP assumes the same, along with lightweight blocks on the inner leaf. You're builder hasn't done that. You'll need to add insulated plasterboard to the internal walls. For the floor, you can use 50mm liquid screed and get another 50mm insulation in. And another 100mm insualtion in the loft is easy and cheap as well.

[HughF]

This is a shocking example of what can go wrong... really shocking that the builder ignored the regs drawings and went with 50mm in the cavity. I bet he didn't tape it either.

[iMCaan]

Not sure what I can say other than to  put up a brave face, again

 

Thanks, will add insulated plasterboard to the internal walls.

Not sure I can add more insulation to the ground floor. To FFL is 100mm insulation, 50mm liquid screed and 10/15mm tiles.

 

Extra insulation between trusses shouldn't be a problem.

 

 

 

[HughF]

7 minutes ago, iMCaan said:

Not sure what I can say other than to  put up a brave face, again

 

Thanks, will add insulated plasterboard to the internal walls.

Not sure I can add more insulation to the ground floor. To FFL is 100mm insulation, 50mm liquid screed and 10/15mm tiles.

 

Extra insulation between trusses shouldn't be a problem.

 

 

 

You can always get the walls blown with beads, as long as there are weep vents at the bottom of the cavity and trays over the openings, you should be fine with the  moisture issue.

[iMCaan]

Thanks. It's an option. I'll give that a serious thought.

[HughF]

Got any photos of the how the insulation went into the walls?

[Adsibob]

8 hours ago, JohnMo said:

You make any room, any temperature you want, with flow balancing.

Can you control the flow balance for each room remotely, away from home?

Edited September 14, 2023 by Adsibob

[JohnMo]

6 minutes ago, Adsibob said:

Can you control the flow balance for each room remotely, away from home?

No, and no need really. Once I set the winter running regime, it will be left to do its own thing.

[iMCaan]

2 hours ago, HughF said:

Got any photos of the how the insulation went into the walls?

Going through the photos, I see that insulation up to first floor did get taped up but not after.

 

(This damage was caused by some teenagers)

 

[Big Jimbo]

@iMCaan bloody little rascals. I'd send them home with broken fingers if i caught them.

[joe90]

5 hours ago, Conor said:

Your builder and architect need to be taken round the back and beaten up.

Or sued for the cost of remedial work required to meet regs. 

[Lofty718]

3 hours ago, Adsibob said:

Can you control the flow balance for each room remotely, away from home?

Why on earth would you need to do this? total nonsense lol

[Adsibob]

5 hours ago, JohnMo said:

No, and no need really. Once I set the winter running regime, it will be left to do its own thing.

I would need to be able to control it remotely. Well, “need” is perhaps a strong word, but I use the remote control quite a lot in winter when our plans change, which they often do, and this saves energy.

 

E.g. we will be spending the afternoon at my parents, my kids might unexpectedly sleep over at their grandparents such that it is helpful to quickly launch my tado app and change the timer on my two kids’ bedrooms and the family bathroom.

 

Or at Christmas we took my uncle to the airport, only to be told on arrival that his flight was cancelled. So before getting in the car to drive home, I tell Tado he’s going to be sleeping in the guest bedroom and using the guest bathroom.

In winter I tweak settings remotely about once a week. In summer I will sometimes tweak the hot water settings to heat extra water when I know I’m going to be using our rather massive bathtub. 
 

We have a large house, which although well insulated is not passive. So helpful to be able to control the heating in each room, and helpful to be able to do it remotely.

[Adsibob]

2 hours ago, Lofty718 said:

Why on earth would you need to do this? total nonsense lol

See my previous post.

[JohnMo]

18 minutes ago, Adsibob said:

I would need to be able to control it remotely. Well, “need” is perhaps a strong word, but I use the remote control quite a lot in winter when our plans change, which they often do, and this saves energy.

 

E.g. we will be spending the afternoon at my parents, my kids might unexpectedly sleep over at their grandparents such that it is helpful to quickly launch my tado app and change the timer on my two kids’ bedrooms and the family bathroom.

 

Or at Christmas we took my uncle to the airport, only to be told on arrival that his flight was cancelled. So before getting in the car to drive home, I tell Tado he’s going to be sleeping in the guest bedroom and using the guest bathroom.

In winter I tweak settings remotely about once a week. In summer I will sometimes tweak the hot water settings to heat extra water when I know I’m going to be using our rather massive bathtub. 
 

We have a large house, which although well insulated is not passive. So helpful to be able to control the heating in each room, and helpful to be able to do it remotely.

Possibly a good example of the difference of radiators and UFH. For our house that just didn't work (I did try), UFH is just way to slow to be putting different temperatures in to different areas and hoping it will keep up. So I either charge the whole lot with heat overnight and leave to give out heat through the day, or when very cold it just gets a longer charge, may even run most the day. Hence no need for zones or any controls other a 0.1 deg hysterisis thermostat timer, to control when the floor charging stops and starts again.

[Dave Jones]

a good example of chasing your tail trying to heat only sections of an insulated box. End up spending more money than if it was all just left to balance.

 

If you have a poorly insulated, leaky shell on the otherhand micro managing and force heating sections may be only option. I remember growing up with the only heating being the open fire, rest of house freezing. No way that fire would heat up whole house no matter how much was put on it. 

[Dave Jones]

13 hours ago, iMCaan said:

Going through the photos, I see that insulation up to first floor did get taped up but not after.

 

(This damage was caused by some teenagers)

 

 

its almost as if whoever designed this had it in for you with that terrible insulation design.

 

100mm of cavity batts would have been 1\4 of the price, be fitted easier and give you a better result.

 

If you paid a 'professional' for this design I'd be instructing solicitors.

 

 

[Adsibob]

15 hours ago, JohnMo said:

Possibly a good example of the difference of radiators and UFH. For our house that just didn't work (I did try), UFH is just way to slow to be putting different temperatures in to different areas and hoping it will keep up. So I either charge the whole lot with heat overnight and leave to give out heat through the day, or when very cold it just gets a longer charge, may even run most the day. Hence no need for zones or any controls other a 0.1 deg hysterisis thermostat timer, to control when the floor charging stops and starts again.

It depends how you spec your UFH. I specified thicker pipes, because I wanted a higher output system, and the possibility of possibly switching to a heat pump in the future. We laid very expensive insulated boards made by Cellecta under the first floor. I can’t remember what they are called, Xflo something. This has resulted in a response time of only 80 minutes or so, so if you’re at the airport and unexpectedly need to bring a guest home, you  switch the call for heat on remotely, and by the time you are home you only need to wait about 20 minutes or so for the room to start warming up. We are fairly well insulated, so even in winter it’s rare that a room is more than 2C or 3C colder than we want it to be, so 80 minutes is manageable.

[iMCaan]

9 hours ago, Dave Jones said:

 

its almost as if whoever designed this had it in for you with that terrible insulation design.

 

100mm of cavity batts would have been 1\4 of the price, be fitted easier and give you a better result.

 

If you paid a 'professional' for this design I'd be instructing solicitors.

 

Qualified architect designed it. According to the builder., his drawings/design was 100% better than the previous architect's drawings.

 

Not had a good experience with the self build from the start. (luckily I didn't go with a turnkey builder, who stayed quite for 2 months and came back to me and reduced the price by £130K, yep £130,000. Initially was recommended by a stone quarry. He built many houses. I asked a few owners and they said they would recommend him and were happy with his work).

 

 

Edited September 15, 2023 by iMCaan