Conversion of outbuilding. What are building regulations?

Bluefox_2

I have just received the survey report on a house I am purchasing. It is a Victorian terrace with a single storey extension at rear. The extension was described by the Estate Agent as a 'Utility Room' but the surveyor says it is really an outbuilding with walls only the thickness of a single brick (4.5"). I want to convert it into a downstairs toilet and shower room but imagine this is now more complicated than just doing the plumbing. Does anybody know the relevant building regs for converting an outbuilding of this type? Do I just need to insulate the walls or is there a lot more to it?

ariba10

Ring the council. You are very often better going to them 'cap in hand' and asking.
I find that on whole they are usualy very helpful.

Nile

Hello Bluefox


Welcome to the MSE site.:wave:

scallaga

the walls floor and roof will have to be insulated to the current building regs .this is not a big job the walls could have a new insulated timber frame wall constructed in the inside with ridgid insulation .the new room would require mechanical ventilation .a saniflo toilet /shower system will make the drainage simple.as advised previosly contact building control with some drawings of your proposals for their advice

calmgirl

(CALMGIRLS HUSBAND HERE) I am asuming that you are converting it into a living space if so then all the building regs apply as they do for a house ie FIRE, SOUND, etc
Go to your locsl council and apply through them it can take up to 12-14 weeks and once you have permission it lasts for 5 years you must start building in that time.

rmb282

As the converted part of the building will be a habitable part it will have to comply with current legislation, there is an amendment due out

Following the link below, to the Governments Building Regulations Website and you can view them in PDF, you need to look at Part L for the current 'U' values, and then check with various products such as Kingspan / Isotherm etc for a relevant insulation. Composite slab insulation is most economical, when it comes to thickness against acheived U values

http://www.odpm.gov.uk/index.asp?id=1130478


Hope this helps

socks_uk

Thanks for the link rmb282... Now I know why electricians are 'part P' registered.

Jill

rmb282

socks_uk wrote:

Thanks for the link rmb282... Now I know why electricians are 'part P' registered.

Jill

I don't think that all electrician are Part P registered, If you get a NICEIC registered its better, You don't have to be an electrician to be Part P registered, just a 'competent' person. Hence the local Building Control Officier will be able to provide a Part P certificate. Thats my understanding anyway, I may have misread the docs.

Bluefox_2

Thanks rmb282. That is a really useful link. I phoned the Building Control Dept at the council and they were quite helpful. The chap said I needed to put a damp-proof membrane and insulation on the wall, insulate the roof and seal the floor using 'asphalt tanking'. He didn't really explain this very well. Does anyone know what 'asphalt tanking' is and is it a DIY job or do I need a contractor?

rmb282

Asphalt tanking is basically applying a bituminous paint to the surfaces therefore sealing it, there are companies that do this work, and therefore indemifies the work, however this is mainly when dealing with habitable cellars or high water table situations. A bituminous tanking paint can be bought from suppliers such as Jewsons. There are other products on the market such as :-
http://www.decoratingdirect.co.uk/Coatings/Bituminous_Paints/
these are not specifically a tanking material but have the same properties, therefore you could undertake this yourself.

You could also look at a tanking membrane, such as:-

http://www.deltamembranes.com/floors.htm

or if you or anyone you know uses fibreglass (for boat building) then this can be used as an excellent tanking membrane.

Ideally it sounds like you need to effectively insulate and dryline the room, but instead of using a plasterboard finish, you could use a hardwood ply such as '18mm WPB' (which is waterproof and used for external use), you could then tile on this using specific tiling adhesives for wood, and a waterproof grout therefore making it a wet room. And then using plasterboard on the ceiling, coated in a vinyl silk paint.

Let me know how you get on.

Bluefox_2

Thanks. I won't be doing the work for a while as haven't completed the purchase yet. What is the main advantage of using ply instead of plasterboard? I assume I would still need to put a polythene membrane behind the insulation