Another From The North Of Ireland (and a hell of a lot more information and self-build chat.)
Posted 28 February 2014 - 09:50 AM
Another member passed me on details of the forum.
I am building a fairly standard traditional 2 storey house just a nice rectangle with a sunroom.
Have planning permission but currently holding up the building control drawings until i can get my head round all the heating and insulation needs.
Currently looking at block build with standard block outer skin, 150 or 200mm cavity with bonded bead insulation and either standard block inner skin or Quinn Lites. (All depends on the figures U-value and ££s)
UFH on both floors and looking at the pricing options of Air Source v Ground Source Heat Pumps. Will also be going for good MVHR with EU7 filtration as there are lots of allergy issues in the family.
Got some good info already from the forum so hoping to continue the learning.
Will hopefully start the build this time next year!
Posted 28 February 2014 - 10:20 AM
Due to planning delays, my wife and I have had almost four years to research and amend the design of our new home and I would say you can never do too much homework! Your questions are almost identical to those we (and I'm sure most other people building a new house) have been deliberating over and the bottom line is that there is no one right answer; factors such as design, budget, priorities, personal preferences and confidence in the available labour are different for each individual case.
Good luck with the build and congratulations for joining what is not only a great information resource, but also a fantastic community where you will find a wealth of kind souls willing to share their first hand experiences openly!
Posted 28 February 2014 - 11:04 AM
Thanks for the welcome. Building outside Mayobridge, (Newry direction for the non-locals)
I know what you mean about delays, first put my planning application through in 2009 but wasnt sure i would get it so didn't start any planning myself.
finding it difficult to get the information i am looking for. Most places give different u-values etc so hoping to get some good advice here.
Posted 28 February 2014 - 11:52 AM
Worth thinking hard about whether going for MVHR or not. If the house is only built to basic building regs airtightness standards (and if block and brick built it will need a fair bit of work to get any better than this) then it's questionable as to whether it's worth the investment in MVHR, in terms of energy saving. The same goes for using heat pumps and UFH, both need a house with good insulation and a fairly modest heating requirement to work well and pay back the fairly big capital outlay.
Things very well worth looking at are increasing the insulation and airtightness performance to levels significantly better the the rubbish minimum standards required in the regs, as this will not only mean that you use less energy heating the house but it will also reduce the cost of the heating system. Given that even an air source heat pump and UFH install is going to cost a pretty penny, especially if it has to be a large one to meet the heating requirement of a poorly insulated house, it's well worth looking at how much it'd cost to improve the insulation, design out cold bridges and improve the airtightness. Nine times out of ten it's cheaper to invest in better insulation and airtightness than it is to shell out for a bigger heating system, plus the saving from the reduced heating requirement will result in lower energy bills for the life of the house.
If going for UFH then make sure you fit a lot of insulation under the floor, as otherwise a fair bit of the heat will just get lost into the ground under the house and wasted. You need a fair bit better than building regs floor insulation, as with UFH the floors will always be warmer than the house, so the rate of heat loss through them will be higher than if the house was heated with radiators. This is well worth sorting out early in the design, as it's hard to increase the floor thickness with added insulation later, as many have found out.
Edited by jsharris, 28 February 2014 - 11:53 AM.
Posted 28 February 2014 - 12:58 PM
It sounds like you are at the point we were at last summer and before I came across this forum.
We have planning for a traditional 2 story house near Portaferry, and were planning a standard block and render build with a GSHP heating system. Eight months and a lot of questions later we are now planning a highly insulated timber frame building that requires very little heating for most of the year.
I can only second Jeremy's post above - Put your money into insulation and ditch the expensive heating system.
Posted 28 February 2014 - 01:01 PM
Posted 28 February 2014 - 01:44 PM
So far the plans for insulation are
Cavity as above trying to figure out which would be better 150mm and quinn lites or 200mm and standard block inner. ( have had quotes for timber frame but they are coming in much more expensive than block.) Cavity will be pumped with bonded beads
200mm Rigid board insulation. Two layers of 50 first cut around services then one layer of 100mm
If not using quinn lites for inner skin will use them for reduced thermal bridging from slab etc.
Air tightness target is 2m3/hr/m2
Will be using cavity closers (not purchased but self made (PIR board and pvc or DPC wrapped timber)
Looking at specific sealers for around the windows and doors and will also use air tightness tapes for junctions
Also looking at detailing for maintaining the air tightness envelope around 1st floor concrete slabs. Something like a radon barrier brought around the slab from the inner skin on the ground floor to the inner skin on the first floor.
Unless there is much more value in the timber frames now i don't think they are really affordable for me. Given the building science is improving so quickly i can only assume that the timber frames would be getting more complex and more expensive.
My site is fairly well sheltered and has a pretty much south facing rear elevation. Glazing areas will be fairly small apart from the sunroom and hoping that very good detailing on-site will get a much better than regulation performing house.
Can anyone recommend a good timber frame company as i would like to get another quote if possible.
Posted 28 February 2014 - 02:06 PM
My only connection is as a customer here in England, but we're pretty pleased with the quality, performance and cost - they were considerably cheaper than getting a block and brick house built here, at around £400/m² for the passive house foundations, insulated frame and guaranteed airtightness to passive house standards (ours came out at 0.49 ACH/hr @50Pa, which is about 1.22m³/h/m² in BR terms).
Edited by jsharris, 28 February 2014 - 02:07 PM.
Posted 28 February 2014 - 02:10 PM
If only i could get reliable U-value information. I seem to see different u-values for the same products i different places.
Posted 28 February 2014 - 02:24 PM
Thanks again. I may get my calculator dusted off!
Posted 28 February 2014 - 03:19 PM
Only gas option would be to get a tank on site but not sure how feasible that would be.
Do you have natural gas available?
Posted 28 February 2014 - 05:22 PM
Posted 28 February 2014 - 05:59 PM
Advanced Timber Craft in Templepatrick have a very versatile way of creating their frames and again appreciate the importance of getting the detailing right. We viewed their show home on Monday evening and so far have found them both accommodating and professional.
You can get a cavity wall to perform well, but the air tightness and thermal bridging details take much more consideration to ensure they can be implemented well on site and you need to appreciate that unless you install additional measures, the plaster coat is your air tightness layer and vapour barrier so anything that breaches it, from a hole for a rawl plug to a socket is a potential compromise to its effectiveness at both jobs.
In most timber frames you create a service void inside the air tightness layer that allows you to run cables and small diameter plumbing without a second thought and can be insulated too by using the right materials. Another benefit with timber framing is that they tend to have a better U value for a given wall thickness.
The cavity wall build up we are pricing includes 100mm block outer leaf, 200mm full filled cavity with GRP or basalt wall ties and a 150mm lightweight concrete block inner leaf. You would get a better U value by replacing the inner leaf with Quinn Lite blocks, but in my view they lack mechanical fixing strength and not everyone finds them easy to lay or plaster. You can now get a gypsum product called hard coat that is supposed to be vastly improved in terms of getting plaster to stay on them and also improves the U value compared to sand/cement, but you can reword that as expensive.
Posted 28 February 2014 - 06:40 PM
Posted 28 February 2014 - 09:59 PM
I didn't take any literature from them, but from memory they can achieve U values ranging from about 0.28 down to 0.09 and can specify anything from a standard strip foundation to an insulated raft such as Supergrund. The flexibility to their system seems to stem from combining different materials in layers around a central structural stud. This can be either 140mm, 200mm(?) or 219mm I beams filled with high density warmcell, OSB with membrane externally which can be clad with either EPS, PIR or woodfibre and Intello to the inside of the stud, then a service cavity which can be filled with sheep's wool, rockwool or hemp. There are more options beyond this, but I fail to remember them.
I believe they are currently working closely with Daly Renewables to make specifying the heating system for each option straightforward and simple to compare the cost/benefit ratio for alterations to the frame build up.
Posted 01 March 2014 - 05:09 PM
Did you get any feel on cost from them ?
Posted 02 March 2014 - 01:19 PM
We were very keen on the block build and concrete floors but the price could sway the decision.
Can anyone comment on the level of sound insulation from the viking house? Also I see UFH pipes are included. Can you have UFH on the first floor or only on the ground floor.
Did everyone go with the breathable window or can you use a ducted HRMV system.
Posted 02 March 2014 - 01:28 PM
Working on a passivhaus now and its unbelievable in terms of how little it needs to stay warm. It was ground frost and deicing the van windows for us when we left our hotel, and the sparky was in a tshirt when we got there. No heating on whatsoever. In the afternoons we were having to leave a door or window open as it was getting uncomfortable to work in. Build a poor house and you'll be paying a large amount of your salary forever, paying RISING energy costs. Build a passivhaus now and that'll not only mean a smaller cheaper heating system, but little or no energy costs if backed up with a renewable energy source. You have to be around one of these types of builds to appreciate what everyone is missing out on. Timber frame with high insulation levels and airtightness is the ONLY way id build now without a doubt.
Edited by Nickfromwales, 02 March 2014 - 10:29 PM.