Heating a new house ?

[Big Jimbo]

I am going to be building a new house from Block and Block. I will aim to try and get the insulation levels slightly better than building regs. I have some understanding of air tightness, and have previously achieved 1.8 on an airtest on a simple block construction. This time i will try to do better on the air test. I would like to think that if i do a decent job that the heating requirement would not be too high. In my mind the problem will be supplying enough hot water to supply a Kitchen, Utility, Downstairs toilet, and 4 Bathrooms. The bathrooms will all have showers, and as in the previous house, if you have got 3 teenagers, It is quite easy to have all 4 showers in use at One time. Any smart ideas, or am i just going to have to have a huge store of hot water ? In the last house i did electric showers in 2 of the bathrooms, but im not sure that would be acceptable in a new, expensive house ? Any good ideas ? Thanks as always for any advice.

[SteamyTea]

1 minute ago, Big Jimbo said:

3 teenagers

Girls or boys?

2 minutes ago, Big Jimbo said:

4 showers in use at One time

Become the master of the house.

2 minutes ago, Big Jimbo said:

insulation levels slightly better than building regs.

Why just slightly?

[Big Jimbo]

1 minute ago, SteamyTea said:

Girls or boys?

Become the master of the house.

Why just slightly?

Either girls or boys. The boys thesedays seem to preen as much as the girls

I am always incharge of the remote control ?

Slightly better, but not stupid because i don't want to end up with walls 3ft thick. However, happy to hear options with block and block build ?

[RichardL]

Put less showers in -  is it a house or hotel ?

[Big Jimbo]

1 minute ago, RichardL said:

Put less showers in -  is it a house or hotel ?

I would have 1 bath with a shower over, and 3 further showers. If you had three teenage girls you would understand the need for each to have there own showers. Avoid the "Mum, xyz is still in the bathroom. I'm going to be late for the school bus" Add, that being screamed  every morning.

[RichardL]

17 minutes ago, Big Jimbo said:

being screamed  every morning.

Fair enough - my comment was flippant yes - but back in the day we had to work this stuff out, I'm sure you did too.

An ensuite for the owner if they're lucky and everyones else shares?

[Temp]

3 hours ago, Big Jimbo said:

I am going to be building a new house from Block and Block. I will aim to try and get the insulation levels slightly better than building regs. I have some understanding of air tightness, and have previously achieved 1.8 on an airtest on a simple block construction. This time i will try to do better on the air test. I would like to think that if i do a decent job that the heating requirement would not be too high. In my mind the problem will be supplying enough hot water to supply a Kitchen, Utility, Downstairs toilet, and 4 Bathrooms. The bathrooms will all have showers, and as in the previous house, if you have got 3 teenagers, It is quite easy to have all 4 showers in use at One time. Any smart ideas, or am i just going to have to have a huge store of hot water ? In the last house i did electric showers in 2 of the bathrooms, but im not sure that would be acceptable in a new, expensive house ? Any good ideas ? Thanks as always for any 

 

MVHR?

 

[Big Jimbo]

32 minutes ago, Temp said:

 

MVHR?

 

@Temp Yes. Otherwise 7 extractors required.

[LSB]

4 hours ago, Big Jimbo said:

I would have 1 bath with a shower over, and 3 further showers. If you had three teenage girls you would understand the need for each to have there own showers. Avoid the "Mum, xyz is still in the bathroom. I'm going to be late for the school bus" Add, that being screamed  every morning.

You are softer than we were 🙂
4 daughters in 5 years, so all teenagers at the same time and 1 shower between then, another bath as well and our ensuite.
They are now in 20's and moved out, but they learnt to get on with it.
And the school picked them up on the doorstep every day so they did have to leave at the same time.
 

[JohnMo]

5 hours ago, Big Jimbo said:

am always incharge of the remote control

That'll be right, you hold it she tells you what you are watching, you fiddle with the controller.

[SimonD]

6 hours ago, Big Jimbo said:

I am going to be building a new house from Block and Block. I will aim to try and get the insulation levels slightly better than building regs. I have some understanding of air tightness, and have previously achieved 1.8 on an airtest on a simple block construction. This time i will try to do better on the air test. I would like to think that if i do a decent job that the heating requirement would not be too high. In my mind the problem will be supplying enough hot water to supply a Kitchen, Utility, Downstairs toilet, and 4 Bathrooms. The bathrooms will all have showers, and as in the previous house, if you have got 3 teenagers, It is quite easy to have all 4 showers in use at One time. Any smart ideas, or am i just going to have to have a huge store of hot water ? In the last house i did electric showers in 2 of the bathrooms, but im not sure that would be acceptable in a new, expensive house ? Any good ideas ? Thanks as always for any advice.

 

I shall sit back and wait for a super @Nickfromwales and @PeterW special which could involve a large diameter mains supply, a mega accumulator, minimum 500l uvc and whole lot more besides - hot water recirculation maybe?

 

In my case, having gone through that kind of design from the kind help here on this forum and costed it up in terms of price and my time, I went down a slightly different route. I only have me,my wife and 2 teenage boys to contend with but still a lot of hot water demand. I currently have limited 15mm mains supply but great pressure and decent flow (I will be trenching and laying upgraded supply pipe at some point), so I opted for a 210l thermal store and have then used relatively small diameter pipework to showers and bath. I've also used flow regulators allowing max 6 liters flow through showers etc. Sounds like too little but is actually fine even with a drench head and allows simultaneous use of 3 outlets without pressure or flow loss and plenty of hot water long enough for showers. I did do a lot of pressure loss calcs with the pipework so flow can be increased when mains is upgraded but so far so good and it has my wife's approval...

[jayc89]

We have 2 bathrooms, downstairs W/C, utility and kitchen and ran 32mm MDPE from our meter (I think it's a 1/2" connection at the water board's side of the meter, but could be wrong on that). We plan to add another en-suite soon but so far it's holding up well. I haven't tested our supply flow/pressure since running the 32mm, but previously on our old 15mm supply, it was pretty poor, around 11 LPM, 1.1 bar working pressure, 3 bar static.

 

I suspect a lot will come down to your internal pipe design. The 32mm MDPE changes to 28mm copper at our internal stop lever and then reduces down to 22mm at the MultiBloc valve. From there we have a "spine" of 22mm that we tee off as and when we need it; 15mm to the bathrooms, kitchen and utility, 10mm to the downstairs W/C. Bathroom W/Cs and basins use a 10mm supply (as the basin's aren't massive), 15mm for the bath/shower. The only run we continue in 22mm is to the master en-suite where we enjoy a more powerful shower (15mm in the family bathroom is fine, but 22mm in the master en-suite provides arguably the best shower I've every been in). We have washing machines running, toilets flushing, up to 2x showers on at once, and the only time I've noticed a noticeable drop in water pressure/flow is when the master en-suite bath is being filled at the same time as the master shower being used. 

[Iceverge]

A big gas boiler and a thermal store would work I would say. 

 

 

 

 

 

[SteamyTea]

4 hours ago, SimonD said:

I've also used flow regulators allowing max 6 liters flow through showers etc

Good move, and as you say, perfectly fine.

My shower is 11 lt/min, it is lovely and guest say it is better than most.

[Radian]

10 hours ago, Big Jimbo said:

4 Bathrooms

What about heat emitters - UFH? Radiators?

3 hours ago, Iceverge said:

A big gas boiler and a thermal store would work I would say. 

 

May be able to work with 'only' 24kW

I would consider PDHW with a heat only boiler that will accept separate demand for HW and space heating. Radiators sized to allow flow temperature at or below 50^oC, HW flow at 70^oC for quick recovery with cylinder stat set to 60^oC

 

[HughF]

Why do you need to factor in hot water to the kitchen? Dishwashers and washing machines are all cold fill these days... And who the heck washes up by hand?

[LSB]

1 hour ago, HughF said:

Why do you need to factor in hot water to the kitchen? Dishwashers and washing machines are all cold fill these days... And who the heck washes up by hand?

I do 🙂

 

[Dave Jones]

we are in same boat. moving from limitless cheap hot water, gas combi, to ASHP. starting with 2 x 250L cylinders and will keep adding them until we dont run out through normal use. Plan is to heat them overnight with ASHP and cheap rate electric. dump solar into them during day.