Isotex build in south east Cornwall

[keith65]

Hi been a gest for about six months so thought I would introduce my self I am a self employed joiner and building a one bed house with integral garage.

Been very interested in the debate on timber frame and icf build methods, and carbon as this can be difficult to see the wood from the trees.

Keith

[Nickfromwales]

Hi Keith, and welcome. 
Isotex in the title so have you made your mind up on ICF?

Also, one bed....does that mean single story or 2 storey? Type of roof etc? 
Info, and more info   

[SteamyTea]

Welcome Keith

 

SE Cornwall, you can smell Devon there.

 

So what do you want to know about the carbon dioxide equivalent emissions and embodied energy of different building methods.

It really breaks down into just two parts.  The carbon dioxide equivalent emissions and embodied energy of the construction materials, divided by how long they will last, and the carbon dioxide equivalent emissions of running the place.

 

Then you will find that a stick built timber frame with lots of cellulose/wood fibre insulation is the best, and it is your skill set.

[keith65]

Hi and thanks for the welcome.

Its a two story build but on a small plot next to a bungalow on a sloping sight so have to dig down a lot. So have gone for the isotex insulated raft and blocks as some is a retaining wall. 

So not low embodied carbon but hope to have very low emissions. 

I will up load some plans and pic later today we just managed to get the raft in before Christmas after shifting 400 tones of soil.

[keith65]

Hi and thanks for the welcome.

Its a two story build but on a small plot next to a bungalow on a sloping sight so have to dig down a lot. So have gone for the isotex insulated raft and blocks as some is a retaining wall. 

So not low embodied carbon but hope to have very low emissions. 

I will up load some plans and pic later today we just managed to get the raft in before Christmas after shifting 400 tones of soil.

2202 - (BR-)04A (1).pdf 2202-(BR-)01C Floor plans.pdf

[keith65]

First load of Isotex block arrived today!

Just need to finish the retaining wall to ground level and can start building?

[keith65]

Hi 

Walls are going up a lot of shifting about as small sight and no space and access for forks so all hand ball. Should be ready for the first pour this coming week.

I have the bracing and rebar to cut to be ready. Looks like we may get some dry days can`t believe the rain we have had since we got started.

[FM2015]

On 04/01/2021 at 08:15, SteamyTea said:

Then you will find that a stick built timber frame with lots of cellulose/wood fibre insulation is the best.

 

Without wanting to open what is a massive can of worms, please show me where stick build has a better life cycle assessment than anything else.  In most cases, LCAs are dependent on time and for some reason, houses are generally linked to a generation, i.e. 25yrs.

 

Over 25yrs, there is some scope for your statement to be true.  After that, most stick builds start to fail, allowing the mass builders to buy the land, knock down the house they've already been paid to build and get paid to build another.  Not only is that the worst con going but it's obsolescence by design masked by LCA.  If you build a house that will last 100+yrs, your LCA will demonstrate that the Carbon embodiment and footprint associated with the build are miniscule when compared with the buildings use over the extended life.

 

So, unless you spend an inordinate amount of money on sourcing decent timber, not sticks, force grown for profit not the environment, wood is not the way to go.

 

 

 

[SteamyTea]

8 minutes ago, FM2015 said:

Over 25yrs, there is some scope for your statement to be true.  After that, most stick builds start to fail, allowing the mass builders to buy the land, knock down the house they've already been paid to build and get paid to build another.  Not only is that the worst con going but it's obsolescence by design masked by LCA

Your statement is not really comparing a self builder's choices, more to do with financing mass building. 

[FM2015]

3 minutes ago, SteamyTea said:

Your statement is not really comparing a self builder's choices, more to do with financing mass building. 

Life cycle assessment of buildings uses a design life which in most studies is standard; 25yrs. 

 

The mass builders effectively build the same house, cheaply, multiple times in the same plot.

 

Stick build and bespoke framing using premium timber are two different things.  Plenty of 300+ yr old timber frame houses about but the materials are very highly priced.  As a self builder, it becomes a matter of choice and budget, and that potentially 300yr old timber framed building will cost more than some alternatives for no additional benefits.  

 

You said stick build was best, based on LCA.  I would disagree.

[SteamyTea]

From:

Model for Life Cycle Assessment (LCA) of buildings

 

"Buildings are designed for long life spans. According to the Eurocode 1990 [41], the structural system of a building is designed for a period of 50 years, the design working life. Nevertheless, with proper maintenance and with the ability to accommodate changes in technical and functional requirements, buildings can last much longer than the design working life, sometimes even centuries"

 

So where does your 25 years come from?

 

[FM2015]

1 hour ago, SteamyTea said:

From:

Model for Life Cycle Assessment (LCA) of buildings

 

"Buildings are designed for long life spans. According to the Eurocode 1990 [41], the structural system of a building is designed for a period of 50 years, the design working life. Nevertheless, with proper maintenance and with the ability to accommodate changes in technical and functional requirements, buildings can last much longer than the design working life, sometimes even centuries"

 

So where does your 25 years come from?

 

That report is full of good information.  And yes, the eurocode sets out an ideal lifespan of 50yrs but the lifespan of some significant individual elements is less.  Which means in the UK, houses are being cleared that are between 17 and 30 yrs old.  Which is bonkers!  Using that data rather than the aspirational eurocode, might be a more appropriate for the UK.  European construction methods and inputs vary greatly just like the results.

 

 

[SteamyTea]

7 minutes ago, FM2015 said:

And yes, the eurocode sets out an ideal lifespan of 50yrs but the lifespan of some significant individual elements is less.

Isn't that like saying because VW cheated on the emissions, all diesel vehicles data is wrong.

We could go around in the circles here, but I have to do and do my CPD now, so that is going to waste some time, that I will never get back.

[FM2015]

On 22/02/2021 at 09:47, SteamyTea said:

Isn't that like saying because VW cheated on the emissions, all diesel vehicles data is wrong.

We could go around in the circles here, but I have to do and do my CPD now, so that is going to waste some time, that I will never get back.

If the fake VW data was used to formulate an average, yes, the average would be wrong.

 

LCA is a useful but wholly imprecise once above a certain level of detail.

[keith65]

Yes there are lots of timber framed houses of 300+ years but the timber used was far superior than the fast grown timber of today and how many timber framed houses built over the last 400 + years are still around a small percentage. I have worked as a joiner for 40 years and have seen the decline in quality of timber it`s hard to understand?

[keith65]

Hi 

Have done the first pour today and all went well and no blowouts so happy days ?

Must say a big thanks to Dennis from Insul Hub for all the help. 

Sleepless night before hand and concrete came late as a brake down at plant but all done and cleaned up by 2pm.

[Nickfromwales]

Aye, Dennis is a top guy. Just tell him I said to lay off the custard donuts and watch him go!!  

[Gav_P]

On 04/01/2021 at 20:42, keith65 said:

Hi and thanks for the welcome.

Its a two story build but on a small plot next to a bungalow on a sloping sight so have to dig down a lot. So have gone for the isotex insulated raft and blocks as some is a retaining wall. 

So not low embodied carbon but hope to have very low emissions. 

I will up load some plans and pic later today we just managed to get the raft in before Christmas after shifting 400 tones of soil.

2202 - (BR-)04A (1).pdf 387.79 kB · 7 downloads 2202-(BR-)01C Floor plans.pdf 1.67 MB · 6 downloads

Loving the progress... we all love pics! 
 

I’ve always wondered about insulated rafts, especially built on a slope, what stops them sliding away? Obviously they are quite heavy things when built, but some heavy rain would worry me. ... I would picture my house disappearing off down the hillside and out too sea. ?

 

 

 

[keith65]

Had plenty of rain so far since starting but not sailed of down the Tamar yet

[SteamyTea]

1 hour ago, keith65 said:

Had plenty of rain so far since starting but not sailed of down the Tamar yet

There did seem an unusual amount of rain this winter.

But gorse fires still happened.

[keith65]

Hi have got up to wall plate and braced the walls, also fitted the pole plates to the walls for the floor joist so the fixings will be set into the concreate. The second pour was Thursday and all went well, so will be building up the gables over the Easter brake and then onto cutting in the roof. So making some progress. 

[Chanmenie]

You are clearly not taking any chances keith, that looks a lot more bracing than is usually specified, but well worth it for the piece of mind 

[keith65]

Talking to the fitters from Isotex it would seem to be about what you should use if your are pouring 10 courses one side was 11 so better to be safe. I have had two pours and all been ok so worth taking the time as I still did not sleep well the night before?

Edited April 6, 2021 by keith65

[SteamyTea]

Are you going to put some glazing into the opening's bracing.  You seem to have a better fit that a window company.

 

3 hours ago, keith65 said:

I have had two pours

One drekley after the other?

[keith65]

I have made the windows and they are sitting in the workshop ready to be fitted after I have cut the roof in. The second pour was a couple of weeks later so drekley as they say.