Builders not wanting to zone house.

[Matt0029]

I think I am correct in saying that building Regs part L1a states that a house over 150 sqm, should have its heating system zoned. However the builders I work for don't want to zone it due to added cost of installation and time. I think they have stated that because the house had its planning permission granted in 1997. They are working to 1997 regs. Not sure if this means they don't have to comply with Building Regs Part L1a any thoughts on this. Thanks.

 

[chris watkins]

To help us understand what is required under the Building Regulations for both new (L1a) & existing (L1b) the Government have produced a Building Services Compliance Guide. Please see link.
https://assets.publishing.service.g.../attachment_data/file/697525/DBSCG_secure.pdf

There is also one for Non-domestic systems L2a & L2b

 

[dan_the_plumber]

To help us understand what is required under the Building Regulations for both new (L1a) & existing (L1b) the Government have produced a Building Services Compliance Guide. Please see link.
https://assets.publishing.service.g.../attachment_data/file/697525/DBSCG_secure.pdf

There is also one for Non-domestic systems L2a & L2b

Yes that’s a useful document Chris, I hadn’t read it in a while. It’s pretty clear that you do need to provide a complete separate carcass for each zone.

 

[chris watkins]

Something else that is often missed is the requirement to insulate primary pipework between the boiler & zone valves / cylinder on new builds.

 

[Ric2013]

Something else that is often missed is the requirement to insulate primary pipework between the boiler & zone valves / cylinder on new builds.

I think this is really important. I generally would use 19mm thick insulation on a 22 pipe for this application, but I realise it isn't really good enough - you can still feel the surface get warm. This seems to be the thickest that Plumbase, for example, stocks, and the manager admits most people don't even use Byelaw thicknesses of 25 and 19mm, even for cold water pipes in lofts!

 

[CHRISX]

Hello Matt0029,

As we know on a Dwelling which is larger than 150 square metres there is a Building Regulations requirement to have `at least 2 Space Heating Zones`.

The Building Regulations definition of a `Zone` has previously been a Heating circuit [ Radiators or other Heat emitters and pipework] which is controlled by a Zone valve and its own Time and Temperature controls.

However I feel that as mentioned above by other Members - compliance could also now be achieved by having Smart controls including some individual WiFi / Bluetooth [?] operated programmable Thermostatic Radiator valves - either on all of the Radiators [Very expensive].

Or just in every Bedroom - the idea being that the Bedrooms being independently `Time and Temperature controlled` from the rest of the Heating system would satisfy the `At least 2 Space Heating Zones` aspect of Building Regulation Part L.

I would advise speaking to the Technical department of a Manufacturer of one of the Smart Heating controls systems which include these WiFi / Bluetooth [?] programmable Thermostatic Radiator valves - they should be able to give a definitive answer as to whether what I described would satisfy the Zoning requirements of Building Regulation L for a property larger than 150 square metres.

I think that this wording from the Domestic Building Services Compliance Guide does describe what I am suggesting:

Page 18 - Section 3.0: Quote:

iii - individual networked radiator controls in each room on the circuit.

End of Quote.

Having obtained an opinion from the Manufacturers Technical department - if possible in an Email - I would then speak to the Building Control Officer to try and get confirmation from Him / Her - ideally being able to show them an Email from the Smart controls Technical department.

Good Luck in resolving this awkward situation.

Regards,

Chris

 

[chris watkins]

Best of luck trying to get any sense out of BC, mine at least can't get their collective heads around un-vent hot water (G3) let alone these types of modern control systems.
As Chrisx suggests above, if you can set up the house with these smart controls so the sleeping areas can be separately time controlled from the living areas & there is some form of room temperature control you will be OK.
The principle is clear - People only need to heat bedrooms when they get up & go to bed so there are clear energy savings to be had by adding time control to allow these areas to be off when the living areas are on.

 

[gpbeck]

Something else that is often missed is the requirement to insulate primary pipework between the boiler & zone valves / cylinder on new builds.

A bit off topic, nut when my thermostat is satisfied the zone valve closes and bypass opens to accommodate pump overrun. With all this insulation, how is heat safely dissipated?

 

[gpbeck]

Something else that is often missed is the requirement to insulate primary pipework between the boiler & zone valves / cylinder on new builds.

A bit off topic, but when my thermostat is satisfied the zone valve closes and bypass opens to accommodate pump overrun. With all this insulation, how is heat safely dissipated?

 

[johnduffell]

A bit off topic, nut when my thermostat is satisfied the zone valve closes and bypass opens to accommodate pump overrun. With all this insulation, how is heat safely dissipated?

The heat is dissipated from the boiler internals to the water in the small loop pretty quickly. The boiler flame itself would cut out pretty much instantly, it's only residual heat you need rid of. If you don't the water in the heat exchanger could be localised boiling which could damage it.

 

[Ric2013]

The heat is dissipated from the boiler internals to the water in the small loop pretty quickly. The boiler flame itself would cut out pretty much instantly, it's only residual heat you need rid of. If you don't the water in the heat exchanger could be localised boiling which could damage it.

True, but some boiler MIs do require a minimum length of pipework. Some even require the bypass to be able to dissipate a minimum amount of heat energy, which means insulated pipework is not good enough for this purpose. In practical terms, though, I suspect you are right that the main thing is to keep the water moving and dissipate the heat over a greater mass of water than is contained in the boiler itself.

 

[chris watkins]

Ric2013 I don't think modern boilers have much of a requirement there is so little residual heat in the condensing exchangers.
The manufacturers may ask for a minimum flow rate to allow the electronics to control the boiler /pump outputs but this is better done by using hydraulic separation via a low loss head or close spaced (coupled) tees rather than a auto by-pass.

 

[Ric2013]

I was thinking of old cast iron boilers when I mentioned minimum heat dissipation, though I note the MAIN HE 24 heat-only boiler has a requirement of a 4m run of 22mm pipe to provide a suitable by-pass. That said, point taken: the MIs do not say anything about not being able to insulate the bypass circuit (as long as there is no plastic pipework used in the system).

 

[johnduffell]

Agree, In fact the building regs require the bypass pipe work to be insulated, a heat dump would be frowned upon even more than a pilot light nowadays!