Celotex

[jocelyn plummer]

My Son lives in a stableman's cottage which is attached to a converted Barn/stables belonging to his Father ( my ex).There is no connecting doorway between the two and they are considering making the stableman's bit a separately owned dwelling.

The 'one up and one down' non listed cottage is Victorian, with its original floors, doors and brickwork etc. On discussing with an Architect the various requirements, for obtaining permisssion to technically separate ownership of the dwelling we were a bit surprised to be told that the internal walls would have to be clad in celotex as part of the process. My Son said he did not give a stuff about heat loss but he does care about the original brickwork and other original features and regards them as part of the reason for living in an old property, not cover them up. Is there any other way, or is this the nanny state again?

 

[Owain]

the insulation could be applied to the stable side of the wall? Or it may be possible to use a whole house calculation and lose the wall insulation by adding extra in the roof, triple glazed windows etc.

 

[MdB]

It may be for sound insulation as well depending on how good the old walls are already.

We did the whole house calculation to enable us to redo our old walls without having to add insulation. Our neighbours didn't and were forced into fitting insulation to their walls. They don't have a cold house now though...

One way of making an improvement elsewhere is to fit a heat pump. This makes a big difference to the calcs.

 

[Zebra]

There may be some leeway. Building Control let me off somewhat, when it came to the older part of my house. Instead of saying I had to meet the standard U values required, they thought this would not be achieved due to the age of the property therefore gave me a more lenient U-value to aim for.

They said that if I didn't require a completion certificate for the renovation of the older parts of the house, then I wouldn't have to put in a Building Notice so they wouldn't enforce these U-value requirements. If I chose to put in a Notice then they would.

In the end, they've checked up on all the building work that's been done on the new extensions, but have completely left me to my own devices when it comes to the old part of the house.

 

[Penners]

Joss - has your son, or the architect, had any discussion with the BCO on this? As has been suggested, it may be possible to negotiate a whole-house heat loss provision that will allow a bit more flexibility on the proposed party wall.

However, I'm making that suggestion out of ignorance. It could equally be that the party wall regulations require a specified level of thermal and sound insulation, regardless of the rest of the property. If this is the case, then I don't think your son has much choice. In the end, however, this may not be such a bad thing. There are few things in life more endlessly irritating than having constant noise nuisance through a party wall.

But, as has been suggested above, perhaps your son might get away with applying the Celotex only to the other side of the party wall.

Ultimately, however, I'm afraid he's going to have to comply with whatever the BCO requires, if he wants to get the attached property accepted as a separate dwelling with sales potential.

 

[stuart45]

When he said internal walls, does he mean the inside of the external walls and not the party wall?
Party walls are subject to fire and sound regs.

 

[Zebra]

And if you do have to install some thermal, sound or fire separation on either the external or party wall, of course you don't have to use Celotex or similar. There are alternative breathable solutions which don't trap damp in the walls - hemp/woodfibre/woodwool for example - although generally they have to be much thicker than the Celotex type, and are more expensive, and you might not need those old walls to breathe if they can do so on the other side.

 

[jocelyn plummer]

OOO, thanks folks for the very helpful comments. We will look into them. it is good to know that there could be some alternative materials, and maybe a less 'destructive' way of dealing with it.

 

[AMc]

AFAIK - separating into another dwelling is a planning matter. Meeting Building Regs isn't directly tied into that.
If the place is already technically a dwelling and needs to be renovated to make it habitable then it depends how decrepit it is already. When I had to negotiate BC the pertinent phrases are related to "renewal" and "repair" of thermal elements (Floors, walls, windows, doors). If you are repairing a thermal element there is no requirement to meet anything other than the current construction. If you are "renewing" by stripping back more than 25% of the thermal element then you are obliged to meet current standards of thermal efficiency where it is practical to do so. There are get outs that relate to historic properties, where meeting current regs would lose more than 5%(?) of usable space or the cost of the work wouldn't meet a simple payback calculation over a set period.
All of the information is in the Building Control notices http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partl/

As others have said you can get a whole house assessment done which may allow you to avoid some measures by over specifying others but you will probably need a "green" heat source to make that work.

If you ask a building professional they are likely to suggest that meeting current regs for every thermal element is the only way forward. For pragmatic reasons the simplest and most straightforward route is to simply follow the BC guidance. It will result in an uncontentious building, no complex calculations and no debate about problems with getting the completion certificate. If you want to do something else then I recommend you start by becoming an expert on PartL1B and try to make a friend in Building Control.

As others have noted there are also rules about fire and sound proofing for party walls which may come into bear on the project.

And a final note of caution. I went about some elaborate work to get permission for residential conversion a big glass vinery - most of the architects I spoke to weren't very well versed in the regs and didn't offer much assistance or objection. Only one practice did really get the regs and warned me that I could probably get the whole house thing to work, but I'd end up with big heating bills and a cold room. I don't regret what we did, but it might have been sensible to compromise on the all glass roof, the heating works but the bills are large. If I'd listened it would probably have been easier.

 

[jocelyn plummer]

Thank you AMc, good advice and has been passed on.!