Building regs query - extractor in kitchen?

[aberdeeneuan]

We'd planned on ducting the extractor in our new kitchen out as it backs onto an outside wall, but due to a design flaw that's not longer an option (the hole would be directly underneath the 2 tonnes of steel holding up the house - I'm guessing plastic ducting won't hold that up!).

So, if I don't duct out, can I just recirculate and NOT fit an extractor? The kitchen has 3 large opening windows in it and the back door, and the builder thinks we need an extractor, the electrician doesn't think we do.

Anyone know?

[HiRich]

I'm pretty confident that, as you already have windows, you don't require an extractor at all.

Many extractors have a recirc option. Elica seem to have a good reputation, with the recirc filters fitting inside the unit. They recommend a flow rate (litres/hour) of ten times the volume of the room, and site at least 70cm above the hob. If using a built-in (rather than chimney-style) just look to duct the exhaust to the top of the room so it doesn't just get sucked straight back in.

[Simpo Two]

My cooker backs against an inner wall and as supplied had a pretty nasty and useless hood which did little. When I refurbished the kitchen I really wanted to have the new hood extracting, and planned to lead a duct through the ceiling void to the opposite wall - but unfortunately there was a central heating pipe in the way (ironically installed during a bathroom refit two years before, doh) which totally foiled my plans. Hence I had to have the recirculating option - the air is drawn through the filter and out of each side of the chimney just under the ceiling. It's not as good but must be legal because Siemens and every other maker sells recirculating hoods.

[Busamav]

To comply with building regs ,If it is a new or altered space, you will need to duct to fresh air.

You can have a cooker hood at 30 litres / sec , or fit an extract fan elsewhere in the room ducted to fresh air at 60 litres / sec

Edited by Busamav on Tuesday 10th November 16:51

[TooLateForAName]

Busamav said:

To comply with building regs ,If it is a new or altered space, you will need to duct to fresh air.

You can have a cooker hood at 30 litres / sec , or fit an extract fan elsewhere in the room ducted to fresh air at 60 litres / sec

60 litres/sec?

Better start nailing down the furniture.

[wizzbilly]

charcol fillter

failing that duct it out from the side of the wall basicly run flat platic boxing across top of unit's to the nearist outside wall

[aberdeeneuan]

wizzbilly said:

charcol fillter

failing that duct it out from the side of the wall basicly run flat platic boxing across top of unit's to the nearist outside wall

We can't duct it as it's between two windows and have no wall units to duct it along, but that would have been the other option. We've had to do this for the extractor in the downstairs toilet which is in the old pantry and we've boxed it in.

[Simpo Two]

aberdeeneuan said:

We'd planned on ducting the extractor in our new kitchen out as it backs onto an outside wall, but due to a design flaw that's not longer an option (the hole would be directly underneath the 2 tonnes of steel holding up the house - I'm guessing plastic ducting won't hold that up!)

Is this steel a lintel/RSJ thing? I don't know the layout but is a 120mm diameter hole underneath really so impossible? Photo?

[aberdeeneuan]

I'll try and take a picture in the morning as we've no light in there at the moment. It's a combination of things. It's a steel rsj (actually, it's a pair of steels) but as it's between two windows the lintels of the windows compromise where you might put it. So we can't do it lower as it's too close to those, any higher and it's too close to the steel. Just a nightmare really!

[Busamav]

TooLateForAName said:

Busamav said:

To comply with building regs ,If it is a new or altered space, you will need to duct to fresh air.

You can have a cooker hood at 30 litres / sec , or fit an extract fan elsewhere in the room ducted to fresh air at 60 litres / sec

60 litres/sec?

.

yup , thats what the regs require.

Recirculating hoods do not meet the requirements

[GTO-3R]

Surely the designer should have picked up on this?

Edited by GTO-3R on Wednesday 11th November 09:15

[aberdeeneuan]

The (new) designer was the one who spotted it.

To put this into context, we knocked the wall between the kitchen and the old utility room out. Both rooms were actually a similar size, but the utility was an extension added in the early 80s.

We had originally put the hob on another outside wall in the utility but it was a compromise. When the builders were taking off the old extension roof (it needed replacing) they discovered that the extension had an issue - the window in it had no lintel and only had a line of bricks on top of it so when they would take the window out, half the wall was looking a bit dodgy. So to replace it (and some crappy rendering I wanted rid off under it) we effectively rebuilt the outer skin of that wall and in the process moved the window to enable us to get the hob between the window.

This shows it before the window was moved and the brick lintel:


The window was moved along to the right by 30cm to give us enough room for a 70cm hob and extractor above it with space either side to make it into more of a feature. However, the designer hadn't thought about the extractor out the wall as it was an outside wall she was happy. We have since binned her and got a new kitchen guy in, and it was him that spotted it.

So basically, we have no space due to the padstone, the lintels on both windows and also the electrics - there is a cable out the back of the wall into the garden for lights.

[Busamav]

you could put a recirculating hood in over the hob , then put an extract fan elsewhere in the kitchen . That will comply .


ps. Has an engineer calculated that Padstone size ?

[aberdeeneuan]

Busamav said:

you could put a recirculating hood in over the hob , then put an extract fan elsewhere in the kitchen . That will comply .


ps. Has an engineer calculated that Padstone size ?

Yup, and been out since and checked it all as well. It's bigger than it looks in that photo.

[aberdeeneuan]

Just for the record, it's been confirmed by building control that you need to have an externally vented extractor of some description. The reason being:

"We don't think people would open the window the let the steam out in winter"

Which is the biggest load of crap I've ever heard in my life. If I have steam in the kitchen, frankly I'll be the judge if I should open the window or not.

Worlds gone mad trying to protect you from yourself, and in the process it's screwing up my kitchen wiring!

[Uonlyhave2seats]

I totally sympathise with you. I have the same issue. We are replacing our kitchen and we want the hob just to the left of a window but we still need to put in an external vented extractor. The kitchen will be open plan with air conditioning but that is not good enough to meet the regs.

What are the chances that the inspector will actually check that the extractor really is vented to the outside and not just decorative?

[Busamav]

Uonlyhave2seats said:

What are the chances that the inspector will actually check that the extractor really is vented to the outside and not just decorative?

I susepct they are high on such a basic item , then you dont get the completion certificate and then have to start cocking around in a finished room.

[Uonlyhave2seats]

Thanks for that. I have not been involved in such a large building project before. Will the building inspector methodically check most things, eg windows opening correctly, fire doors, smoke alarms, correct number of low voltage lights etc? The reason I ask is that so far he has just taken a brief glance at the structural stuff and walked away happy.

[Busamav]

Uonlyhave2seats said:

Thanks for that. I have not been involved in such a large building project before. Will the building inspector methodically check most things, eg windows opening correctly, fire doors, smoke alarms, correct number of low voltage lights etc? The reason I ask is that so far he has just taken a brief glance at the structural stuff and walked away happy.

It varies from inspector to inspector , and also the trust that he has in the builder .

But , if you have had queries with him regarding a particular item , expedct him to cast an eye over it.

Smoke alarms should come under the electrical certificates that he will require and fire doors will be self evident .

Most of these guys are there to protect you from unscrupulous builders , , you pay for their service and they are acting for you , it is not uncommon for a suspect builder to try to create "an us and them" situation

[hairyben]

How impossible is extracting from the hood? 9x1" flat duct DOWN and out, chased in and tiled over?

Every effort should be made to extract via the hood, carbon filters ain't cheap, ain't half as good, and will cost more as they need changing frequently to work properly.