Newbie - Norfolk Solid wall build

[bradders3109]

Hi All

 

I am about to embark on a renovation and extension self build for the first time.  Very daunting.

 

The property is a 1920s solid wall construction and I hope to build the extension using 7nm block laid flat to provide a 220mm solid wall.  The whole building will then be wrapped in external wall insulation and faced with brick slips.  A MVHR system will control the air exchanges in the completed property.

 

I'm sure that I will have lots of questions along the way so look forward to receiving you feedback both positive and negative but all hopefully constructive.

 

Existing and proposed plans attached.

 

Regards

 

Mark

Plans.pdf

[PeterW]

Welcome !

 

Any reason for the block on flat ..? Could do similar with 140mm blocks and save yourself quite a lot on blocks, mortar and labour. Will also give you a bit more space in the rooms - if all your insulation is outside then you may as well have the additional room inside. 

[bradders3109]

Hi Peter

 

Thanks for the response.

 

The original house is 9 inch solid wall and laying the blocks flat would get me close to this.  I also thought that laying flat would increase wall stability.  I worked in Gibraltar about ten years ago on a build that was done in this manner.

 

I'm an electrician by trade but will be doing as much of this build as I can on my own.  Tight budget so any savings on blocks would be welcome if it doesn't compromise structural integrity.

 

cheers

 

Mark

 

[joe90]

Welcome to THE self build forum. If 9” are not necessary structurally then I agree with @PeterW, 140mm would save money/blocks and give you more room or insulation. We love questions so bring it on ?

[bradders3109]

Thanks Joe

 

The laid flat block would be for external walls which will carry steels and floors and will be tied into the original building.  Internal ground floor walls I'll lay in the normal manner.  the first floor and dormer will be studwork.

 

Do you know if a 140mm external solid wall would be acceptable to building control?  I can an will ask when I am dealing with them.  At the minute the architect is drafting the building regs drawings.

 

Cheers

[PeterW]

Single skin 100mm is good to 9m height ( @Gus Potter..??) from memory with pilasters so 140mm would be fine. Keep the runs below 7m without a return wall or support and you’ll be golden. 

[joe90]

2 minutes ago, bradders3109 said:

At the minute the architect is drafting the building regs drawings.

He should know!!! If not people here will tell you. (As per above).

[bradders3109]

Thanks guys

 

There won't be any walls longer than 7m without corners.  The ridge height will be 9.5m do you think this extra half meter would be ok as it's on the gables not full walls?

 

Joe, I'm a little frustrated with the architect, I've looked over his first draft of the BR drawings and it talks about securing rafters to the cavity wall.  I've clearly told him that I would like a solid wall as I don't see any point in the cavity with external insulation, I may be wrong.  happy to be corrected.

Plans.pdf

[joe90]

@bradders3109 at the risk of upsetting someone, I am not a fan of architects and the only reason I employed one was to convert my pencil drawings to CAD and add annotations in “building speak”. He managed to cock that up and he had to do it 3 times. I designed my house and I did it within budget!!,. You might be better off with an architectural technician, they do all the drawings as you want them (and may be cheaper). 

[joe90]

30 minutes ago, bradders3109 said:

as I don't see any point in the cavity with external insulation,

Correct

30 minutes ago, bradders3109 said:

I may be wrong. 

No.

[bradders3109]

Thanks Joe 

 

really appreciate your comments especially on Christmas eve.  I'm really pleased that you agree with my approach regarding the cavity.  People have been looking at me like I've got two heads when I talk about not building a cavity wall.

 

I have employed an architectural technician so perhaps I'm getting what I'm paying for and it's much cheaper than an architect.  I didn't put that across properly.  I won't be airing my dirty washing on here except to say that I have felt a little on my own and had to correct things at various stages.

 

What I'm really looking for is someone to sign of the building regs and provide advice and guidance along the way.  I'm now looking at a company called Stroma,  have you heard of then or had any dealings?

 

 

 

 

 

 

 

[joe90]

1 hour ago, bradders3109 said:

really appreciate your comments especially on Christmas eve.

(Gets me out of doing the veg fir tomorrow ?)

 

1 hour ago, bradders3109 said:

I have felt a little on my own and had to correct things at various stages.

been there. Done that. You are not on your own with this crowd, lots of very useful Advise and opinion, don’t be afraid to ask, we are a friendly bunch ?

[PeterW]

@bradders3109 Stroma deal in sustainability. Sounds like you need a decent structural engineer on the job more than anything - Your regs plans aren’t complicated from looking at your plans. 

[bradders3109]

Thanks Peter,

 

I've spent the last two hours surfing the site to find out how our intended MVHR affects building regs.  Architect is stating trickle vents for the windows in his drawings.  This looks to be counter intuitive to me.  Interested to read about issues with noise which I hadn't thought about.

 

I really am starting from scratch here and whilst I do need a good structural engineer, I think I also needed an architect who has worked with MVHR before and trying to create an airtight (as possible) property.

[Gav_P]

Don’t have trickle vents!! You’ll just fill them as soon as you can once you have moved it. They are drafty even when closed and let a fair amount of noise in too. 

Also, I’m guessing that if you are going for MHVR then it won’t work properly.

[bradders3109]

Thanks Gav

 

My thoughts entirely.  I think my first mistake and the one that I'm now dealing with is that I chose an architect without asking if he'd dealt with MVHR before.  : (

 

 

[Gav_P]

2 minutes ago, bradders3109 said:

Thanks Gav

 

My thoughts entirely.  I think my first mistake and the one that I'm now dealing with is that I chose an architect without asking if he'd dealt with MVHR before.  : (

 

 

But at least having a technician means they will just draw what you tell them. So make sure you are very clear about air-tightness and insulation. Making sure things like cold bridges are designed out. There is loads of stuff on this in the forum, and plenty of people who know a lot about this too. 
 

I have done something very similar to you, large 2 story extension and full reno of the existing... my biggest regret is not have a good enough understand at the design stage of the above. 

[Russell griffiths]

Understanding air tightness is something you can work out with a couple of evenings reading. 

I think you will need to go through a few architects before you find one who understands it as much as you do. 

[bradders3109]

Thanks Gents,

 

Just found this 

 

http://www.passivhaustrust.org.uk/UserFiles/File/Technical Papers/ROT/How to build a Passivhaus_Chapters 1 to 4.pdf

 

a little light reading before santa comes I think.

[joe90]

I am not sure you need a structural engineer, building regs and info from here should suffice I recon. I designed my own MVHR instal, it’s not rocket science and fairly straightforward, quite a few of us has done the same. Enjoy your reading and bring on those questions. 

[Iceverge]

Welcome Mark,

 

As mentioned time spent at the design phase is invaluable and I feel your pain in trying to find the right professionals. To oft it seems the case "I've always done it this way" or else you are expected to fund someone's ego trip. 

 

Nonetheless with research and care an amateur can achieve a very good quality build as many on here can testify. 

 

External insulation is an excellent way of cutting thermal bridges and and I think you're on the right track.

 

The passive house magazine have a guide on it and other topics that I found useful.

https://passivehouseplus.ie/magazine/guides/the-ph-guide-to-external-insulation

 

How far down the road of the design process are you?

 

Jonathan

 

 

 

 

[bradders3109]

Thanks for the link Jonathan.  Very good read.

 

Currently I've had the building plans passed and my architect is working on the building regs drawings but as mentioned earlier it appears that he is used to dealing with conventional builds and doesn't appear  to be thinking about EWI or MVHR in his regs drawings.

 

We are currently living in two touring caravans on the plot and it isn't the best experience so I'm keen to get the two downstairs and two upstairs rooms at the front of the house up to a habitable state before starting the extension.  This involves replacing the suspended timber floors with concrete slabs which I'm underway with.  Now awaiting structural engineers calcs to inform me of the depth of the foundations for the internal walls (7nm block).  These will also provide a break between the different floor slabs.  We are 400 meters from the sea and having lifted the suspended floor what was beneath can only be described as a beach.  So we are building on sand.

 

I'm enjoying myself though and so pleased that I found this forum at such an early stage.

[joe90]

27 minutes ago, bradders3109 said:

We are 400 meters from the sea and having lifted the suspended floor what was beneath can only be described as a beach

I renovated a cottage in Shropshire, miles from the coast but digging down I came to sand (the Shropshire plain used to be underwater decades ago apparently), the BCO asked me to just put some steel mesh in the footings, job done.

[Iceverge]

Have you plans to convert the garage to living space at any stage?

 

Your architect will probably do a good job regarding the building regs but it sounds like you need a better person to draw up construction details. 

 

Unless they can concisely explain EWI window details etc thank them for their time and get someone else. Ideally someone with passivhaus/low energy experience. If they can't explain it in simple terms they don't understand it. 

 

Design wise I'd alter a few things.

 

1. Move the utility to the garage side and make it bigger. 

2. I'd bin the chimney in the extension. If you're desperate for a stove use one of the existing fireplaces. 

3. Don't bother with knocking through the back wall of the sitting room. A lot of work and expense for little gain. 

 

Keep the hopes up. 

 

 

[bradders3109]

Hi Iceverge,

 

Thanks for your comments.

 

There are no plans to ever change the garage at any point.  It will be effectively my workshop.

 

Quote

Unless they can concisely explain EWI window details etc thank them for their time and get someone else. Ideally someone with passivhaus/low energy experience. If they can't explain it in simple terms they don't understand it. 

 

I think you are right on this and I'm nearing the point of do so.

 

Quote

1. Move the utility to the garage side and make it bigger. 

 

This would involve having to move the drain and probably dig a new inspection chamber.

 

Quote

2. I'd bin the chimney in the extension. If you're desperate for a stove use one of the existing fireplaces. 

 

I wanted the stove in the big room but have been questioning myself as I'm not sure that I'd use it that much in a well insulated house.  It may be too hot.

 

Quote

3. Don't bother with knocking through the back wall of the sitting room. A lot of work and expense for little gain. 

 

I will be doing this myself therefore the extra work I don't see as a problem.  I retired to renovate and extend this house.  Time is one of the few  commodities that I think I have enough of (god willing).

 

I really appreciate you looking at the plans and your feedback. 

 

 

Keep the hopes up