External Wall Insulation 17 May 2021 at 12:22AM in In my home (includes DIY) MoneySaving 13 replies 523 views

superM

Hello, 
My property is semi detached in Birmingham. 
I am confused, does planning permission required for external Wall Insulation?  It's not listed property and not in conservative area. 
On my road none of the properties are rendered so if apply external Wall and rendered will that need planning? 
I am aware building regulations are required. 
Thanks 
MS

FreeBear

If the materials used change the external appearance of the property, then PP may be required - Best to give your local council a call.

Do give thought to the detailing especially if you have bay windows or a limited overhang of the roof. A few of the 1920/30s properties had EWI done under the old Green Deal scheme (the one where you repaid the loan as part of your energy bill). In my opinion, they all look piggin' ugly for having the work done... I'm for internal wall insulation as it is easier to DIY and doesn't affect the external appearance. Downside is a slight loss of floor space, but does give one the opportunity to redecorate.

Rosa_Damascena

FreeBear said:

If the materials used change the external appearance of the property, then PP may be required - Best to give your local council a call.

Do give thought to the detailing especially if you have bay windows or a limited overhang of the roof. A few of the 1920/30s properties had EWI done under the old Green Deal scheme (the one where you repaid the loan as part of your energy bill). In my opinion, they all look piggin' ugly for having the work done... I'm for internal wall insulation as it is easier to DIY and doesn't affect the external appearance. Downside is a slight loss of floor space, but does give one the opportunity to redecorate.

To redress the balance, I had external insulation and silicone render at 100mm thickness in total and it does the job and looks good too. Its not something I shall be looking to repeat for the next 30 years.

FreeBear

Rosa_Damascena said: To redress the balance, I had external insulation and silicone render at 100mm thickness in total and it does the job and looks good too. Its not something I shall be looking to repeat for the next 30 years.

If done well, and attention is paid to the finishing detail, it is good. But it does have to be done right, and doesn't suit every property.

OilyByker

CAVITY or NOT.  If your  walls have a cavity, EWI is a waste of money. Why heat up the cavity ???? If other homes are rendered go ahead

Rosa_Damascena

OilyByker said:

CAVITY or NOT.  If your  walls have a cavity, EWI is a waste of money. Why heat up the cavity ???? If other homes are rendered go ahead

Explain to me this then - if you are having new external walls built, do they have to be cavity? What is the point of the cavity of the government just turns round and tells you to fill them up with foam? And then the foam causes damp??!

(Small brain, easily confused  - but I need to know before my external walls go up).

stuart45

An external wall doesn't have to be a cavity wall. It has to meet the regs  and the most popular way with masonry is the cavity wall with part or full fill insulation. Solid walls like this are not so popular on new buildsH+H | External Walls: Solid Wall Construction (hhcelcon.co.uk)

fenwick458

Rosa_Damascena said:

OilyByker said:

CAVITY or NOT.  If your  walls have a cavity, EWI is a waste of money. Why heat up the cavity ???? If other homes are rendered go ahead

Explain to me this then - if you are having new external walls built, do they have to be cavity? What is the point of the cavity of the government just turns round and tells you to fill them up with foam? And then the foam causes damp??!

1 Cavity wall, built with solid part fill insulation = Best solution
2 Cavity wall, retrofitted with blown in insulation, it's efficient but you have lost the cavity, so if any water gets in from the outer leaf of blocks or bricks it will go through to the inside. also can be tricky to get everywhere full of insulation, sometimes they miss bits when blowing it in.
3 cavity wall, clad with external insulation. this is more expensive, and with an open cavity you'll still be safe from damp bridging the cavity, but it's not as efficient, if the cavity is well ventilated the draughts can take a lot of the heat away
4 cavity wall, clad with internal insulation. problem is you lose floor space. and fixing to the walls becomes harder but it's probably the most efficient solution in terms of heat loss and maintaining an open cavity to stop damp getting in
thats my basic thoughts on it, probably even more variables with different types of construction and insulation

grumbler

OilyByker said:

CAVITY or NOT.  If your  walls have a cavity, EWI is a waste of money. Why heat up the cavity ???? If other homes are rendered go ahead

brick+cavity+brick+insulation

insulation+brick+cavity+brick

The order you follow when adding numbers (thermal resistances) doesn't matter. The only restriction is that the cavity can't be the first and the last.

stuart45

Rosa_Damascena said:

OilyByker said:

CAVITY or NOT.  If your  walls have a cavity, EWI is a waste of money. Why heat up the cavity ???? If other homes are rendered go ahead

 but I need to know before my external walls go up).

Has the construction method of your wall been decided yet, or is it being left to your builder?
They will probably do a cavity wall, which could be either full or part fill. Full could be batts or boards, part fill boards fixed to the inner skin.

owcal

superM said:

Hello, 
My property is semi detached in Birmingham. 
I am confused, does planning permission required for external Wall Insulation?  It's not listed property and not in conservative area. 
On my road none of the properties are rendered so if apply external Wall and rendered will that need planning? 
I am aware building regulations are required. 
Thanks 
MS

Hi, it's not necessary for planning permission on externally insulating existing walls, I recently got my house externally insulated by a company call Lotus Energy, they ran me through any questions I had. 

Worth a shot!