Bedroom to ensuite
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Discussion

gotoPzero

Original Poster:

19,652 posts

210 months

Tuesday 26th August 2025
quotequote all
We are lacking an ensuite to our master bedroom. We have been in a year now and we knew at some point we would want to tackle this problem.

There is a bedroom directly behind the master which would make a good dressing room and ensuite if we add a partition wall.

The main issue is there isnt any water or waste in the bedroom. So I would probably have to pay professional plumber / builder to make those services good.

We have 3.4m ceilings so I was thinking, would it be possible to add a sub floor of say 300mm and have 2 x 150mm steps going up. Then run the waste and water under that?

Then add a false ceiling which would allow water to be fed in from above for showers and easy access for lighting - is this allowed for regs?

The room is fairly large, 20m2 ish (4.5x4.5) so I was thinking of making the ensuite a room within a room? Anyone done this before?

Is there some major flaw in my plan?


mattvanders

411 posts

47 months

Tuesday 26th August 2025
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Worth noting the direction of the floor joists to run pipework more easily (clean water less of an issue due to small bore and at pressure but waste water pipes will be larger and you wouldn’t want to cut lots of holes in the joists to get it through one side of the room to the other). You could always drop down into the room below and box in if not.

gotoPzero

Original Poster:

19,652 posts

210 months

Tuesday 26th August 2025
quotequote all
Thats why I was thinking of a sub floor - avoids cutting joists.

But I cant quite figure out if thats ok with building regs?

I could potentially keep the floor level the same and build a false wall too, and run the waste in the cavity of that - but again not sure how regs would look at that. I know it needs a good fall.

LooneyTunes

8,719 posts

179 months

Wednesday 27th August 2025
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It’d be fine (we’re doing pretty much exactly what you’re proposing to add another en-suite in a renovation) but you’re unlikely to need a floor void anywhere near 300mm: the fall needed on drainage isn’t very much at all as you need there to still be a bit of pressure behind solids to move them along the pipe.

Slagathore

6,176 posts

213 months

Wednesday 27th August 2025
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Can the en-suite be done so the new waste can go straight out the wall and pick up an external stack?

A lot of it will depend on where you can bring the pipes from. You can probably get away with a false/stud wall and run it all behind that. That could also created a ledge or the depth you'd need if you want niches etc.




Dr Mike Oxgreen

4,412 posts

186 months

Wednesday 27th August 2025
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If your plumber uses the “S” word, slap him hard around the face. Unless he also uses the words “avoid” and “plague” in the same sentence.

Saniflo. Just don’t!

Leptons

5,479 posts

197 months

Wednesday 27th August 2025
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Why?

MattyD803

2,155 posts

86 months

Wednesday 27th August 2025
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Noise and Reliability.

Notorious for both.

Watcher of the skies

1,033 posts

58 months

Wednesday 27th August 2025
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MattyD803 said:
Noise and Reliability.

Notorious for both.
My sister in law got so annoyed with hers when it packed up that she kicked it causing it to split.
All I can say is that I'm glad I wasn't there.

Sheepshanks

38,816 posts

140 months

Wednesday 27th August 2025
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As others have suggested, even a full size soil pipe doesn't need that much space and the fall needed is surprisingly slight.

It's a good size room - it'd be great to be able to utilise most of it, with the possible caveat that it will take some heating to make it comfortable, especially with hefty ventilation. Perhaps for that reason reducing the height might make sense.

TriumphStag3.0V8

5,018 posts

102 months

Wednesday 27th August 2025
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Saniflo (other brands of macerator are available) should only be a last resort. We had one, I had to replace it twice (even though we followed the directions about what can go through them religiously).
If you do have to go that route, put a full-bore stop valve in the outlet pipe close to the unit. When the unit has to be removed (which it will), you will be glad that it is there, just remember to open it again when it is all reconnected......

That's before you get to the noise they make - even the quiet ones. Our next door neighbour in a previous (semi-detached) house had one, could hear the damned thing through the wall.

gotoPzero

Original Poster:

19,652 posts

210 months

Wednesday 27th August 2025
quotequote all
It will have to be a real toilet as the mrs wants a Japanese toilet.

We have a saniflow style toilet in one of the other bathrooms I suspect they did it to avoid planning.

Its loud, we flush it once every couple of days and thats about it - its used as an emergency only really as we have 2 other toilets in the house.

I didnt notice when we viewed the house - because if I had I would have asked more questions but it is what it is now.

The ensuite I am planning I think the best is going to be a fake wall with all the soils and wastes going out into that and then out into the soil stack which is on the exterior wall of that bedroom. The bonus would be the floor can remain at its current level.

I think the main issue is going to be getting water to the room. I think my next step is to get a planning type person to have a look at it because I am not confident what I would plan out would be permitted.

Rough101

2,917 posts

96 months

Wednesday 27th August 2025
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gotoPzero said:
It will have to be a real toilet as the mrs wants a Japanese toilet.


I think the main issue is going to be getting water to the room. I think my next step is to get a planning type person to have a look at it because I am not confident what I would plan out would be permitted.
Bidet style stuff needs another tank so you can air gap the mains from the pan.

Planning are only interested in what it looks like outside unless it’s listed, it’s Building Regs approvals you need.