extension

chaklie

hi im building a large extension onto my small home,out of all the different types of builds ie, block ,timberframe, icf,whats the best ? looking to have the building energy efficient !

Villain

They all have their advantages and disadvantages, I just started a build recently and while I think ICF is a good system, I firmly believe to use it you need to put an outer leaf on the outside, i.e. block, brick or stone like you do on a timber frame house as even the arcylic render's don't give a strong enough finish. That made it too expensive for me.

I went for standard block construction and I will have extra insulation on the inside of all external walls, I also have large solar gain with small North facing windows and very large south facing windows.

250882

very hard to say which method is BEST all have their merits and downfalls

-Blockwork - thermally massive, takes a long time to heat up, difficult to get a very good u-value(cozy boarding, increased cavitys cause problems with cills etc.) but very cost efficient compared to most newer technologies.
-Timber frame - quick to put up, easier to spec higher insulation but can be a disaster if the frame manufacturer isnt good.
-ICF - I have seen some real cowboys at this and some complete horrorstories. of all the jobs I've seen done with this stuff its put me off completely. If you are only going single storey fair enough but if its 2 or more stories beware. It is expensive and fairly untested in ireland but if done correctly it is a good system.

Mellor

The system also has to be compatable with the existing build type.

sinnerboy

250882 wrote: »

-ICF - I have seen some real cowboys at this and some complete horrorstories. of all the jobs I've seen done with this stuff its put me off completely. If you are only going single storey fair enough but if its 2 or more stories beware. It is expensive and fairly untested in ireland but if done correctly it is a good system.

2 systems have IAB certs . AFAIK 2 also have BBA certs .

However , I don't think any are targeting extensions works

ircoha

250882 wrote: »

very hard to say which method is BEST all have their merits and downfalls

-Blockwork - thermally massive, takes a long time to heat up, difficult to get a very good u-value(cozy boarding, increased cavitys cause problems with cills etc.) but very cost efficient compared to most newer technologies.
-Timber frame - quick to put up, easier to spec higher insulation but can be a disaster if the frame manufacturer isnt good.
-ICF - I have seen some real cowboys at this and some complete horrorstories. of all the jobs I've seen done with this stuff its put me off completely. If you are only going single storey fair enough but if its 2 or more stories beware. It is expensive and fairly untested in ireland but if done correctly it is a good system.

While I accept this thread is about an extension, the above post needs to be addressed.
An issue missing from this contribution is a failure to consider the running costs of any system, with particular focus on the annual heating cost.
It is unhelpful to focus on the initial building costs and ignore the annual running costs.

The math is quite simple: a 15% increase in building costs for one system over another can lead to a 75% reduction in annual heating costs, at current prices, over the lifetime of the building, giving a simple payback period on the 15% upfront cost of about 10 to 12 years.

A more rigorous present value calculation over the lifetime of the building makes an even more compelling argument.

A focus on initial costs, coupled with poor building standards and even poorer building practices is not an optimal approach.

As a footnote, I cannot t see the benefit of the particularly vitriolic remarks on ICF, then being tempered with

if done correctly it is a good system.

I would have thought that

if done correctly it is a good system

applies to all of them.