External Insulation?

uptowngirly

Hi all!

My architect(who's also my cousin!) is a big fan of external insulation - from what I've been reading on the various threads, it seems like a more expensive method of insulation - any clever people who know if this is true??;)

We're building a 260 sqm single storey (double height in some areas) house (subject to planning permission!)

What are people's views on the best type of insulation (bearing in mind we're in a recession so it needs to be as cheap as possible without stinting on quality) Easy peasy!!

Thanks in advance xx

L driver

uptowngirly,
Lots of threads about this in boards. What are you comparing it to? "Best" and "cheap" in the in the same sentence is a bit Irish. Quality and futureproofing is what you should be looking for.
For what it's worth and I'm no expert here are my thoughts on any new build.

-Get the most from your orientation, the sun smiles for free
-Reduce thermal bridges to a min
-Get air and wind tightness right
-Get the u values right from the start, have a holistic approach not bit by bit

If I was to start a new build in the morning here is what I would do,
- Insulated raft foundation with both wet heating pipes/electric cables installed,
that's that till finishing, no cold bridge and alot of work out of the way.
-A quality timberframe/aircrete block with external eps insulation. Both with walls to passive u value
-My roof would be truss at 600mm centres again insulates to passive levels, with cellulose and softboard.
-Windows would be triple glazed, argon etc, checked from wep
-A breathing window/mvhr for ventilation.
All of the above with my orientation/air tightness respected. To do this is not all that complcated, we have a mild climate so to reach passive levels is not that big of a deal. We have no building control so anything is game, it is up to you to ensure the quality of your build.
Hope that helps a bit, again I'm no expert and not technical with figures that's what your friend/archi is for, hope you are still friends after:D Maybe some of the other posters might correct me on stuff.

braftery

+1 to LDrivers comments on "best" and "cheap", and in fact to his entire post.

"Cheap" does not always equal "Good Value" and never equals "best".

In answer to your initial question;

EWI (External Wall Insulation) is a very effecient method of insulating a building. Currently in Ireland, as it is a relatively new "in use" method it appears still carry a small premium. It is made more attractive for people upgrading their home by the Large Home Improvement Grant (€4,000). However as a new build you can not avail of this grant.

All of the building methods (block, timber frame, SIP,etc), have pros and cons. At the end of the day the variation in cost between them is not overly significant. The floor area, the design of your house and the level of finish detail will have a much bigger impact. (ie: Kitchens come from €5k to €50k and floors are sold by the metre).

If you are planning a new self-build, research will aid your decisions, preparation will aid your budgeting & scheduling and constant day to day management of your build will save you money.

The devil is in the detail.

uptowngirly

Thanks so much both of ye!

Of course, you're dead right regarding the cheap/best quality comment - what I really meant was the best value for money - I've learned so much from reading all the various threads here and I was unsure regarding external insulation, if it was worth the additional money.:o

This self-building process really is a minefield!!

L-Driver - I agree totally about the window orientation - we have the house positioned so that all big windows (which will be alu-clad triple glazing) are on the South and West side of the house. The reason we are going for triple glazing is because it seems more efficient (if that's the right word) at capturing and retaining the heat from the sun. We have enough space on the south facing roof for solar panels and we are sold on getting them as well (still alot of reading to do regarding flat and tubular mind you!!)

I am now aware of what uvalue means, so there's some hope for me (fingers crossed!!)

I'm now off to research thermal bridges and how to ensure there are no cold bridges at the start without having to find out about them with a heat imaging camera after the house is complete and how to achieve wind/air tightness in a block build!!

Thank you both for taking the time to reply - it really is amazing the amount of knowledge and help that people are willing to give in their own free time and it is much appreciated xx:)