Hi all

Just a point of interest really....

Does anyone know whether heating system "design" is regulated for
new builds in any way?

Most contributors here I'm sure will know that, to run efficiently
in condensing mode, the system temperature for condensing
installations needs to be rather lower than older systems. This
means larger radiators are needed to supply satisfactory heat
input to a room with a given heat loss.

It is in the installer's interest to fit smaller radiators at a
lower overall cost. But this would lead to a higher less
efficient system temperature being necessary to sufficiently heat
the property.

Does anyone know if checks are done for heating system efficiency,
particularly on major builders' sites?

If not, then the claimed boiler manufacturer efficiencies will be
meaningless.

Thanks

Phil

--


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On Sun, 24 Jan 2021 17:43:54 +0000, thescullster wrote:

Does anyone know whether heating system "design" is regulated for
new builds in any way?


Through Gassafe and the Boilers Manufacturers Warranty.

The Housebuilders will have very little input on what the Heating people
put in.It will be a sub contractor who does the heating work, and they
will have that Contract through being the cheapest Tender. All the
Housebuilder will demand is a radiator in each room and a boiler to give
the correct heating characteristics for the house. They will not check
the designs.
The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

Also of course a lot, and I mean a lot of people seem to be getting their
boilers replaced at the moment for condensing ones using the old radiator
runs, what effect does that have on the assumed better economy of the new
boiler? Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Alan" wrote in message
o.uk...
On Sun, 24 Jan 2021 17:43:54 +0000, thescullster wrote:

Does anyone know whether heating system "design" is regulated for
new builds in any way?


Through Gassafe and the Boilers Manufacturers Warranty.

The Housebuilders will have very little input on what the Heating people
put in.It will be a sub contractor who does the heating work, and they
will have that Contract through being the cheapest Tender. All the
Housebuilder will demand is a radiator in each room and a boiler to give
the correct heating characteristics for the house. They will not check
the designs.
The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

On 25/01/2021 08:16, Alan wrote:
On Sun, 24 Jan 2021 17:43:54 +0000, thescullster wrote:

Does anyone know whether heating system "design" is regulated for
new builds in any way?


Through Gassafe and the Boilers Manufacturers Warranty.

The Housebuilders will have very little input on what the Heating people
put in.It will be a sub contractor who does the heating work, and they
will have that Contract through being the cheapest Tender. All the
Housebuilder will demand is a radiator in each room and a boiler to give
the correct heating characteristics for the house. They will not check
the designs.
The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.



The builder may well do so. But that doesn't mean they can get away
with it. As usual, it all depends on the contract. Builders don't
/have/ to provide any heating. But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer. Heating systems are also
covered by the standard insurance polices and they do have things to say
about heating systems if they are provided. E.g.

https://nhbc-standards.co.uk/8-services/8-1-internal-services/8-1-10-space-heating-systems/



--
Robin
reply-to address is (intended to be) valid

On 24/01/2021 17:43, thescullster wrote:
Hi all

Just a point of interest really....

Does anyone know whether heating system "design" is regulated for
new builds in any way?

Most contributors here I'm sure will know that, to run efficiently
in condensing mode, the system temperature for condensing
installations needs to be rather lower than older systems. This
means larger radiators are needed to supply satisfactory heat
input to a room with a given heat loss.

It is in the installer's interest to fit smaller radiators at a
lower overall cost. But this would lead to a higher less
efficient system temperature being necessary to sufficiently heat
the property.

Does anyone know if checks are done for heating system efficiency,
particularly on major builders' sites?

If not, then the claimed boiler manufacturer efficiencies will be
meaningless.

Thanks

Phil


Don't Building Regs make you adhere to something like the
SAP rating of the proposed construction ?.

A farming friend built a new bungalow on his land and the
BCO made him fit a particular type of fire-behind-glass
which he had every intention of removing so he could have
a blazing open fire instead. Not sure what the outcome was.

On 24 Jan 2021 at 17:43:54 GMT, "thescullster"
wrote:

Hi all

Just a point of interest really....

Does anyone know whether heating system "design" is regulated for
new builds in any way?


Related piece in the Guardian today:


https://www.theguardian.com/environm...e-them-greener

Householders buying brand new homes in the next four years are likely to find
an unpleasant surprise awaiting them in the futu homes built today will
have to be retrofitted with energy efficiency measures and low-carbon
technology, at an average cost of more than £20,000.


--
Cheers, Rob

On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so. But that doesn't mean they can get away
with it. As usual, it all depends on the contract. Builders don't
/have/ to provide any heating. But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer. Heating systems are also
covered by the standard insurance polices and they do have things to say
about heating systems if they are provided. E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.

On Mon, 25 Jan 2021 08:30:16 +0000, Chris Hogg wrote:

On Mon, 25 Jan 2021 02:16:30 -0600, Alan wrote:

On Sun, 24 Jan 2021 17:43:54 +0000, thescullster wrote:

Does anyone know whether heating system "design" is regulated for
new builds in any way?


Through Gassafe and the Boilers Manufacturers Warranty.

The Housebuilders will have very little input on what the Heating people
put in.It will be a sub contractor who does the heating work, and they
will have that Contract through being the cheapest Tender. All the
Housebuilder will demand is a radiator in each room and a boiler to give
the correct heating characteristics for the house. They will not check
the designs.

I understand that the heating engineer does a calculation taking into
account the room sizes, outside wall areas etc, to work out the number
and sizes of the radiators needed and hence the boiler capacity. There
are probably formulae on boiler or radiator mfrs web sites for doing it.
From what the OP was asking, that formula ought to include the
temperature that the boiler is set to, or do the formulae just assume a
value, such as 65C or whatever?

I very much doubt that there are any calculations done regarding boiler
feed and return temperatures compared to the room sizes and a standard
temperature for that room.
They'll just see a 3 metre square room, think 'we'll need a 600btu
radiator for that room' and that is as far as the calculations will go.

On 25/01/2021 16:59, Alan wrote:
On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so. But that doesn't mean they can get away
with it. As usual, it all depends on the contract. Builders don't
/have/ to provide any heating. But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer. Heating systems are also
covered by the standard insurance polices and they do have things to say
about heating systems if they are provided. E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.


I repeat, it all depends on the contract: if your contract is with the
builder for a house with a heating system then then it's the builder who
is liable if the heating system is faulty.



--
Robin
reply-to address is (intended to be) valid

On 25/01/2021 15:54, RJH wrote:
On 24 Jan 2021 at 17:43:54 GMT, "thescullster"
wrote:

Hi all

Just a point of interest really....

Does anyone know whether heating system "design" is regulated for
new builds in any way?


Related piece in the Guardian today:


https://www.theguardian.com/environm...e-them-greener

Householders buying brand new homes in the next four years are likely to find
an unpleasant surprise awaiting them in the futu homes built today will
have to be retrofitted with energy efficiency measures and low-carbon
technology, at an average cost of more than £20,000.



More project fear from the Labour party. Building regs are never
retrospective, apart from updating gas and electrical installations.

And no-one knows where that mythical £20K figure comes from. The
Grundian article avoided any elaboration too.

Houses being built today are far more energy efficient than
the millions+ built in the 1970's and 80's.

Remember, it was NuLabs 'warm house' project that resulted in
Grenfell Tower being clad the way it was.

On 25/01/2021 17:03, Alan wrote:
They'll just see a 3 metre square room, think 'we'll need a 600btu
radiator for that room' and that is as far as the calculations will go.
and mostly they wont be *wrong*

--
€œPuritanism: The haunting fear that someone, somewhere, may be happy.€�

H.L. Mencken, A Mencken Chrestomathy

On 25/01/2021 17:12, Robin wrote:
On 25/01/2021 16:59, Alan wrote:
On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so.Â* But that doesn't mean they can get away
with it.Â* As usual, it all depends on the contract.Â* Builders don't
/have/ to provide any heating.Â* But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer.Â* Heating systems are also
covered by the standard insurance polices and they do have things to say
about heating systems if they are provided.Â* E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.


I repeat, it all depends on the contract: if your contract is with the
builder for a house with a heating system then then it's the builder who
is liable if the heating system is faulty.





Or the architect?

This post is about design flaws not failures.

OK so this is a refurb and not a newbuild I am working on.

It is massively over specced but seems to give little consideration to
anything to do with assisting the boiler to modulate.

It also probably has the worst UFH setup I have ever seen - I had a
regular poster pop in and have a look at it so that he knows how not to
do it when he fits his own UFH.

It's going to end up with overheated rooms and cold rooms.

All fitted to the architects specs and drawings.


--
Adam

ARW wrote:

OK so this is a refurb and not a newbuild I am working on.

It is massively over specced but seems to give little consideration to
anything to do with assisting the boiler to modulate.

It also probably has the worst UFH setup I have ever seen - I had a
regular poster pop in and have a look at it so that he knows how not to
do it when he fits his own UFH.

It's going to end up with overheated rooms and cold rooms.

All fitted to the architects specs and drawings.

For UFH all the manufacturers will take a floor plan and return a
pipework plan that splits it up into different zones with one or more
loops per zone ... I doubt the architect does much more that cut and
paste that.

The design of that system would probably benefit from having more than
one manifold location to have run the loops from.

On 25/01/2021 18:41, ARW wrote:
On 25/01/2021 17:12, Robin wrote:
On 25/01/2021 16:59, Alan wrote:
On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so.Â* But that doesn't mean they can get away
with it.Â* As usual, it all depends on the contract.Â* Builders don't
/have/ to provide any heating.Â* But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer.Â* Heating systems are also
covered by the standard insurance polices and they do have things to
say
about heating systems if they are provided.Â* E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.


I repeat, it all depends on the contract: if your contract is with the
builder for a house with a heating system then then it's the builder
who is liable if the heating system is faulty.





Or the architect?

This post is about design flaws not failures.

OK so this is a refurb and not a newbuild I am working on.

It is massively over specced but seems to give little consideration to
anything to do with assisting the boiler to modulate.

It also probably has the worst UFH setup I have ever seen - I had a
regular poster pop in and have a look at it so that he knows how not to
do it when he fits his own UFH.

It's going to end up with overheated rooms and cold rooms.

All fitted to the architects specs and drawings.



Good point. If your contract with the builder is "work to these specs
from the architect" then architect's tender bits are on the block for
design faults.





--
Robin
reply-to address is (intended to be) valid

ARW wrote:

OK so this is a refurb and not a newbuild I am working on.

Is the whole thing anywhere near done yet?

In message , Andy Burns
writes
ARW wrote:

OK so this is a refurb and not a newbuild I am working on.

Is the whole thing anywhere near done yet?

One difficulty we discovered with a refurb and planned underfloor
heating throughout is adequate insulation over solid floor slab.

The original arrangement with wall hung radiators had 25mm polystyrene
under 22mm chipboard. The new system uses slotted polystyrene slabs with
about... 25mm of insulation below the pipes!

We could have put more under but only by losing ceiling/door height.

--
Tim Lamb

On Tuesday, 26 January 2021 at 07:31:39 UTC, Robin wrote:
On 25/01/2021 18:41, ARW wrote:
On 25/01/2021 17:12, Robin wrote:
On 25/01/2021 16:59, Alan wrote:
On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so. But that doesn't mean they can get away
with it. As usual, it all depends on the contract. Builders don't
/have/ to provide any heating. But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer. Heating systems are also
covered by the standard insurance polices and they do have things to
say
about heating systems if they are provided. E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.


I repeat, it all depends on the contract: if your contract is with the
builder for a house with a heating system then then it's the builder
who is liable if the heating system is faulty.





Or the architect?

This post is about design flaws not failures.

OK so this is a refurb and not a newbuild I am working on.

It is massively over specced but seems to give little consideration to
anything to do with assisting the boiler to modulate.

It also probably has the worst UFH setup I have ever seen - I had a
regular poster pop in and have a look at it so that he knows how not to
do it when he fits his own UFH.

It's going to end up with overheated rooms and cold rooms.

All fitted to the architects specs and drawings.

Good point. If your contract with the builder is "work to these specs
from the architect" then architect's tender bits are on the block for
design faults.
--
Robin
reply-to address is (intended to be) valid

But how many building contracts stipulate that the builder *must* follow the design information? I've never seen it. A client would be mad to agree to that.

A designer works to a "reasonable skill and care" duty - so only liable if he or she drops below that. An architect copying and pasting a bespoke design from a UFH supplier would probably meet that duty of care, assuming the UFH designer was supplied with all necessary info.

Building contracts put a higher duty of care on the builder - a fitness for purpose. Any client who reduces the builder's liability by insisting on "work to these specs" deserves what they get...

Tim Lamb wrote:

One difficultyÂ* we discovered with a refurb and planned underfloor
heating throughout is adequate insulation over solid floor slab.

UFH for a refurb is obviously more difficult than a new build, from what
I can remember it's mostly(?) the new bits of Adam's site have UFH and
hopefully decent insulation under, the old bits have radiators, but it
looked like a rat's nest in the corridors.

On 26/01/2021 09:10, Nikki Smith wrote:
On Tuesday, 26 January 2021 at 07:31:39 UTC, Robin wrote:
On 25/01/2021 18:41, ARW wrote:
On 25/01/2021 17:12, Robin wrote:
On 25/01/2021 16:59, Alan wrote:
On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so. But that doesn't mean they can get away
with it. As usual, it all depends on the contract. Builders don't
/have/ to provide any heating. But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer. Heating systems are also
covered by the standard insurance polices and they do have things to
say
about heating systems if they are provided. E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.


I repeat, it all depends on the contract: if your contract is with the
builder for a house with a heating system then then it's the builder
who is liable if the heating system is faulty.





Or the architect?

This post is about design flaws not failures.

OK so this is a refurb and not a newbuild I am working on.

It is massively over specced but seems to give little consideration to
anything to do with assisting the boiler to modulate.

It also probably has the worst UFH setup I have ever seen - I had a
regular poster pop in and have a look at it so that he knows how not to
do it when he fits his own UFH.

It's going to end up with overheated rooms and cold rooms.

All fitted to the architects specs and drawings.

Good point. If your contract with the builder is "work to these specs
from the architect" then architect's tender bits are on the block for
design faults.
--
Robin
reply-to address is (intended to be) valid

But how many building contracts stipulate that the builder *must* follow the design information? I've never seen it. A client would be mad to agree to that.

A designer works to a "reasonable skill and care" duty - so only liable if he or she drops below that. An architect copying and pasting a bespoke design from a UFH supplier would probably meet that duty of care, assuming the UFH designer was supplied with all necessary info.

Building contracts put a higher duty of care on the builder - a fitness for purpose. Any client who reduces the builder's liability by insisting on "work to these specs" deserves what they get...


Yes - although IIRC traditional JCT contracts used to put liability for
design faults on the designer rather than the builder if they were at
the same level. (And it comes back to me, I think also allowed for a
design and build contract to explicitly put liability for design faults
on the subcontractor - but I could /very/ easily be wrong.)
--
Robin
reply-to address is (intended to be) valid

On Tuesday, 26 January 2021 at 10:35:53 UTC, Robin wrote:
On 26/01/2021 09:10, Nikki Smith wrote:
On Tuesday, 26 January 2021 at 07:31:39 UTC, Robin wrote:
On 25/01/2021 18:41, ARW wrote:
On 25/01/2021 17:12, Robin wrote:
On 25/01/2021 16:59, Alan wrote:
On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so. But that doesn't mean they can get away
with it. As usual, it all depends on the contract. Builders don't
/have/ to provide any heating. But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer. Heating systems are also
covered by the standard insurance polices and they do have things to
say
about heating systems if they are provided. E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.


I repeat, it all depends on the contract: if your contract is with the
builder for a house with a heating system then then it's the builder
who is liable if the heating system is faulty.





Or the architect?

This post is about design flaws not failures.

OK so this is a refurb and not a newbuild I am working on.

It is massively over specced but seems to give little consideration to
anything to do with assisting the boiler to modulate.

It also probably has the worst UFH setup I have ever seen - I had a
regular poster pop in and have a look at it so that he knows how not to
do it when he fits his own UFH.

It's going to end up with overheated rooms and cold rooms.

All fitted to the architects specs and drawings.

Good point. If your contract with the builder is "work to these specs
from the architect" then architect's tender bits are on the block for
design faults.
--
Robin
reply-to address is (intended to be) valid

But how many building contracts stipulate that the builder *must* follow the design information? I've never seen it. A client would be mad to agree to that.

A designer works to a "reasonable skill and care" duty - so only liable if he or she drops below that. An architect copying and pasting a bespoke design from a UFH supplier would probably meet that duty of care, assuming the UFH designer was supplied with all necessary info.

Building contracts put a higher duty of care on the builder - a fitness for purpose. Any client who reduces the builder's liability by insisting on "work to these specs" deserves what they get...

Yes - although IIRC traditional JCT contracts used to put liability for
design faults on the designer rather than the builder if they were at
the same level. (And it comes back to me, I think also allowed for a
design and build contract to explicitly put liability for design faults
on the subcontractor - but I could /very/ easily be wrong.)
--
Robin
reply-to address is (intended to be) valid

With "Traditional" building contracts (e.g. with BoQs etc) there is definitely more cost risk with the client, but this comes with a better control over quality, supposedly. But the performance risk still sits with the contractor due to the difference in duty of care. The contractor can only offload a claim if it can prove a designer was negligent.

In terms of D&B, liability can be a minefield. But even then, a contractor is still signed up to a fitness for purpose while designers have to only use reasonable skill and care.

On Tuesday, 26 January 2021 at 10:35:53 UTC, Robin wrote:
On 26/01/2021 09:10, Nikki Smith wrote:
On Tuesday, 26 January 2021 at 07:31:39 UTC, Robin wrote:
On 25/01/2021 18:41, ARW wrote:
On 25/01/2021 17:12, Robin wrote:
On 25/01/2021 16:59, Alan wrote:
On Mon, 25 Jan 2021 11:50:23 +0000, Robin wrote:

On 25/01/2021 08:16, Alan wrote:

The Builder will deny all responsibility for heating faults and design
failures, and point you to the Heating Engineers if there is a fault.

The builder may well do so. But that doesn't mean they can get away
with it. As usual, it all depends on the contract. Builders don't
/have/ to provide any heating. But most new builds will have heating;
and I've not heard of buyers being told they need to enter into a
separate contract with the heating engineer. Heating systems are also
covered by the standard insurance polices and they do have things to
say
about heating systems if they are provided. E.g.

https://nhbc-standards.co.uk/8-servi...rvices/8-1-10-
space-heating-systems/

Yes, but the Builder will just say it is not our problem, we'll ring the
plumbers and get them to look at it, then they'll ring the plumbers, and
tell them to sort it. So there is a guarantee, but, the builders have
sub'd the work out, hence the plumbers are liable.


I repeat, it all depends on the contract: if your contract is with the
builder for a house with a heating system then then it's the builder
who is liable if the heating system is faulty.





Or the architect?

This post is about design flaws not failures.

OK so this is a refurb and not a newbuild I am working on.

It is massively over specced but seems to give little consideration to
anything to do with assisting the boiler to modulate.

It also probably has the worst UFH setup I have ever seen - I had a
regular poster pop in and have a look at it so that he knows how not to
do it when he fits his own UFH.

It's going to end up with overheated rooms and cold rooms.

All fitted to the architects specs and drawings.

Good point. If your contract with the builder is "work to these specs
from the architect" then architect's tender bits are on the block for
design faults.
--
Robin
reply-to address is (intended to be) valid

But how many building contracts stipulate that the builder *must* follow the design information? I've never seen it. A client would be mad to agree to that.

A designer works to a "reasonable skill and care" duty - so only liable if he or she drops below that. An architect copying and pasting a bespoke design from a UFH supplier would probably meet that duty of care, assuming the UFH designer was supplied with all necessary info.

Building contracts put a higher duty of care on the builder - a fitness for purpose. Any client who reduces the builder's liability by insisting on "work to these specs" deserves what they get...

Yes - although IIRC traditional JCT contracts used to put liability for
design faults on the designer rather than the builder if they were at
the same level. (And it comes back to me, I think also allowed for a
design and build contract to explicitly put liability for design faults
on the subcontractor - but I could /very/ easily be wrong.)
--
Robin
reply-to address is (intended to be) valid
My SiL had a problem with his heating system shortly after they moved in to their new build, he notified the builder and because the site was still under construction the foreman/ clerk of works came round. During the conversation with him he mentioned that the boiler supplier, Ideal in this case, was responsible for the design and installation of the system. The contents of the airing cupboard which included the DHW tank and all the controls arrived as a preassembled kit simply put in the cupboard and connected to the first fix pipe work and if I remember correctly it was a man from Ideal who came to fix the issue likewise when a radiator valve leaked.

Richard

On 26/01/2021 11:18, Nikki Smith wrote:
On Tuesday, 26 January 2021 at 10:35:53 UTC, Robin wrote:
On 26/01/2021 09:10, Nikki Smith wrote:
snip


But how many building contracts stipulate that the builder *must* follow the design information? I've never seen it. A client would be mad to agree to that.

A designer works to a "reasonable skill and care" duty - so only liable if he or she drops below that. An architect copying and pasting a bespoke design from a UFH supplier would probably meet that duty of care, assuming the UFH designer was supplied with all necessary info.

Building contracts put a higher duty of care on the builder - a fitness for purpose. Any client who reduces the builder's liability by insisting on "work to these specs" deserves what they get...

Yes - although IIRC traditional JCT contracts used to put liability for
design faults on the designer rather than the builder if they were at
the same level. (And it comes back to me, I think also allowed for a
design and build contract to explicitly put liability for design faults
on the subcontractor - but I could /very/ easily be wrong.)
--
Robin
reply-to address is (intended to be) valid

With "Traditional" building contracts (e.g. with BoQs etc) there is definitely more cost risk with the client, but this comes with a better control over quality, supposedly. But the performance risk still sits with the contractor due to the difference in duty of care. The contractor can only offload a claim if it can prove a designer was negligent.

In terms of D&B, liability can be a minefield. But even then, a contractor is still signed up to a fitness for purpose while designers have to only use reasonable skill and care.


The good old default in English law: architects, engineers and other
designers can shrug their shoulders if their design isn't buildable.



--
Robin
reply-to address is (intended to be) valid

On 26/01/2021 08:57, Tim Lamb wrote:
In message , Andy Burns
writes
ARW wrote:

OK so this is a refurb and not a newbuild I am working on.

Is the whole thing anywhere near done yet?

One difficultyÂ* we discovered with a refurb and planned underfloor
heating throughout is adequate insulation over solid floor slab.

The original arrangement with wall hung radiators had 25mm polystyrene
under 22mm chipboard. The new system uses slotted polystyrene slabs with
about... 25mm of insulation below the pipes!

We could have put more under but only by losing ceiling/door height.


Don't worry. According to the ?polyplumb salesman at a
self-build exhibition that I visited many years ago, he
assured me that even though the overlay slotted
insulation panels were only an inch thick, it would
still be cheap to run because 'heat rises'.

In message , Andrew
writes
On 26/01/2021 08:57, Tim Lamb wrote:
In message , Andy Burns
writes
ARW wrote:

OK so this is a refurb and not a newbuild I am working on.

Is the whole thing anywhere near done yet?
One difficulty* we discovered with a refurb and planned underfloor
heating throughout is adequate insulation over solid floor slab.
The original arrangement with wall hung radiators had 25mm
polystyrene under 22mm chipboard. The new system uses slotted
polystyrene slabs with about... 25mm of insulation below the pipes!
We could have put more under but only by losing ceiling/door height.


Don't worry. According to the ?polyplumb salesman at a
self-build exhibition that I visited many years ago, he
assured me that even though the overlay slotted
insulation panels were only an inch thick, it would
still be cheap to run because 'heat rises'.

Ha! I suspect I am warming a lot of Hertfordshire. I think TNP suggested
the main loss is to the sides rather than directly down.

It has crossed my mind to consider external insulation down to the
footings. Currently shingle filled French drain so not a huge job but
without some idea of the benefit, not over likely to happen.

--
Tim Lamb

On 26/01/2021 15:07, Tim Lamb wrote:
In message , Andrew
writes
On 26/01/2021 08:57, Tim Lamb wrote:
In message , Andy Burns
writes
ARW wrote:

OK so this is a refurb and not a newbuild I am working on.

Is the whole thing anywhere near done yet?
Â*One difficultyÂ* we discovered with a refurb and planned underfloor
heating throughout is adequate insulation over solid floor slab.
Â*The original arrangement with wall hung radiators had 25mm
polystyreneÂ* under 22mm chipboard. The new system uses slotted
polystyrene slabs withÂ* about... 25mm of insulation below the pipes!
Â*We could have put more under but only by losing ceiling/door height.


Don't worry. According to the ?polyplumb salesman at a
self-build exhibition that I visited many years ago, he
assured me that even though the overlay slotted
insulation panels were only an inch thick, it would
still be cheap to run because 'heat rises'.

Ha! I suspect I am warming a lot of Hertfordshire. I think TNP suggested
the main loss is to the sides rather than directly down.

Building Regs Part L used to have tables of Uvalues or heatloss
associated with the perimeter. If you only insulate a 1 metre band
around the edge (inside) that is most of the downward heatloss fixed.

It has crossed my mind to consider external insulation down to the
footings. Currently shingle filled French drain so not a huge job but
without some idea of the benefit, not over likely to happen.

Sarah Beaney built a new mansion in Somerset (recent TV series)
and the inner edge of the foundation trenches were lined with
what looked like the blue extruded polystyrene that is ?normally
used under the slabs of coldrooms, and then the concrete poured.

Andrew wrote:

the inner edge of the foundation trenches were lined with
what looked like the blue extruded polystyrene

Sure that wasn't to prevent clay heave on the foundations?

On 26/01/2021 09:24, Andy Burns wrote:
Tim Lamb wrote:

One difficultyÂ* we discovered with a refurb and planned underfloor
heating throughout is adequate insulation over solid floor slab.

UFH for a refurb is obviously more difficult than a new build, from what
I can remember it's mostly(?) the new bits of Adam's site have UFH and
hopefully decent insulation under, the old bits have radiators, but it
looked like a rat's nest in the corridors.

Yes the new build bit had good insulation under the concrete.

And the screed over the pipes lifted because the plumbers took the heads
off the UFH manifold instead of using the rooms stats and gently
building up the temperature. They said the blending valve was at minimum
and there was too little screed.

Personally I would have started the UFH running before the laminate was
laid to allow the moisture to escape.

And out of all that pipework (you never saw the copper pipework in the
loft) there was just one leak.

--
Adam