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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
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    Hello. Just bought a house near Malton with the intention to wrap in insulation and render, put in triple glazed windows, solar panels and we were thinking biomass but seen a report on the BBC saying that its not such a good idea. Its a big job and I am currently battling my way through quotes for windows and EWI. Any one has any suggestions I am all ears..thanks very much in anticiption:bigsmile:
    • CommentTimeMar 13th 2017
    3G Windows - Russell Timbertech - price unbeatable by far.
    Biomass is becoming the bad boy of heating - certainly here in towns and villages you can see a layer of smoke on windless days - OK most of the culprits are burning out dated stoves but none the less you can see the results. Biomass tends to be expensive to install by the time you have got the boiler and a TS, and there is also the space needed to run the system. What other options are available to you, I presume mains gas is not available but if you went for a different fuel e.g.gas(LPG) or oil or even heat pump what would the cost difference be.

    What is your target heat load? and what thickness EWI are you planning, there is not much difference in cost between 100mm and 200mm beyond the extra cost of 100mm of EPS

    If you can get your heat load down enough it doesn't matter much what sort of heating you have - best case a fan heater for a couple of weeks a year !!
    Thanks for the replies.....

    I am learning fast about the biomass situation. It has taken me some months to even get people to quote and there seemed to be quite a number of cowboys out there. So far quotes came in at 20 - 25K :surprised: My regular plumber said he felt that biomass was going to be an expensive option and also that eventually we would be shipping them in from Russia to keep up with demand..then I read the BBC article and thought if we insulate well (cant get passivhaus level but can get as close as we can) then the heating requirement will be small. I am now trying to find a company to install the EWI and render. Have found a company called wetherby render systems who i am waiting for their quote and also yorkshire specialist rendering. They quoted £11700 for the house insulation plus render. He reckoned £65 a square metre on 180m2 but i thought that seemed cheap per sq mtre. We have to work out how we extend the roofing to overhang the render but there is no reason why we cant make it 200mm.

    Must have done my research well on here as waiting for a quote for the windows from Russell Timbertech. I am also waiting for Polish Interiors, fine aluminium, reynaers, ,munster joinery, vrogum. Had received one from Velfac £45k :shocked::shocked::shocked: and i also read on here that the render has to go on before the windows with Velfac. Currently in a 17th century farmhouse single glazed sash windows so anything will seem like a dream!!
    You mentioned solar panels - there is a strong possibility that they would not make sense over PV (due to the cost of PV now meaning solar panels only make sense in some very specific circumstances), are you in the Uk, do you have plenty of nicely orientated roof space, if both of these are true it is almost certain that you should dump the solar panels for PV.
    • CommentAuthorEd Davies
    • CommentTimeMar 13th 2017
    Both PV and solar thermal are sorts of solar panels. Which people mean in any context is often hard to tell so it's often worth asking for clarification rather than assuming.
    Yes sorry for not being more specific.. I have a quote for PV panels at £6,500 for 4kw. I am going to convert one of the outdoor sheds into a workshop and put the panels on there budget willing. I will be working from home during the day so will utilise the power then - put the washer on etc.
    • CommentTimeMar 13th 2017
    Wetherby are well-known; I haven't heard of Yorkshire Specialist but I'm not in the area or doing retrofit.

    Extending the overhang is reasonably straightforward. Competent builders should be able to explain.

    £6,500 for 4 kWp is a top of the range price for PV panels I think.
    As per archit xt for insulation as follows....
    Showing 50mm on the walls and 25mm to the reveals of windows and doors.

    I have spoken with Kingspan the insulation people and they said:

    Existing wall U-value is approx 0.54W/m2K
    With 50mm insulation this falls to 0.23W/m2K
    With 60mm insulation this falls to 0.2W/m2K

    Building Control would be looking for 0.3W/m2K
    What type of walls do you have? (cavity, solid brick etc)
    The figures quoted sound like it is the phenolic insulation, otherwise I don't think that the insulation value would be so good with only 50mm. Generally speaking it is cheaper to use EPS and have a thicker amount (unless there is a good reason that requires the insulation to be as thin as possible).

    Is the Kingspan insulation vapour permeable?

    Building Control would be looking for 0.3W/m2K - yes but that's nothing to be proud of !!!
    Ok that doesn't sound good. That is the thickness the architect recommended. I will have to ask him if we can get it thicker. It's a cavity wall that has already been insulated with foam. We have no over hang whatsoever on the roof so there would need to be some adjustment to that.
    You can buy the boards as thick as you like, but what you can achieve will depend on available space (lack of) roof overhang etc. A colleague used 180 phenolic in 2 90mm layers. Phenolic is (apocryphally?) suggested to shrink more than platinum EPS.
    Posted By: peacebabe68That is the thickness the architect recommended.

    Generally speaking architects will only specify what will pass building regs. unless asked to do otherwise.(The famous architect of this parish is an exception)

    Posted By: peacebabe68We have no over hang whatsoever on the roof so there would need to be some adjustment to that.

    If you are going to increase the overhang of the roof anyway then it will make little difference how much increase you put on.

    Get some other quotes using standard EPS and platinum (graphite) EPS, look at the relative costs and how much overhang is needed in each case. All other things being equal i.e. you need to increase the overhang anyway, I would expect standard EPS to be the cheapeest. IMO a target of 0.1.5W/m2K and 0.2W/m2K would be reasonable targets against which to get quotes.

    Posted By: peacebabe68It's a cavity wall that has already been insulated with foam.

    Foam filled cavities do not have a good reputation. Like any cavity fill much depends upon the quality of workmanship - and it is very difficult to check after the event. About the only way I know to check is to wait for a cold morning and heat the house up lots(over night) and then take pictures with a thermal camera.
    Ok thanks for all your comments. The architect has said that the house to be insulated /rendered is 70m2 and if we upgraded going for 100mm of insulation we would get a U-value of 0.14W/m2K. The cavity wall insulation was done before we bought the house and I dont rate it anyway. Would have preferred if they hadnt bothered. Is there a way to work out the material costs to heating running costs? We are intending to live in this house for a long time - if not until we die! -so the view is to get this as best as possible from the start. Removing biomass from the equation puts us back to oil fired boiler or ASHP so to make it as insulated as possible is the first big plus.
    • CommentTimeMar 14th 2017
    If replacing the windows, then no need for the horrid compromise of thin EWI to the existing reveals, back to the existing window position, which knocks great holes in your thermal envelope and diminishes the effectiveness of your EWI investment.

    Remove the existing and fit the new windows further outboard, in the EWI zone. Lovely new deep internal window cills. Much advice on here as to how to mount the new windows. Admittedly this only becomes completely uncompromised when the EWI is a lot thicker than you envisage - 150mm minimum, 200 better, or even whatever PassiveHouse Enerphit standard demands - why not? - but you're contemplating eaves extension to make that thickness possible. Again, as djh says, lots of advice on here about extending eaves.

    For EWI supply-only, Parex is my vote - at least in SW England their regional Rep is absolutely top notch, visits, sorts out products reqd for the particular situation, gives advice/guidance to your local chippy/handyman (fitting the EPS) and plasterer (rendering) - all easy work, specialists no longer necessary.
    Thanks fostertom. Spoke to the parex rep who pointed me towards someone who I had made contact with already. He is talking about EPS boards? Not quite sure but will meet him on site to discuss. He reckons approx £70m2. I am now going to have to look at the window fitting because Velfac are definate that they want the windows fitting post render but most render people say that cause a seal problem round the windows and they would prefer to render to the window. This chap I have just spoken to said he has done a big job recently were the aluminium/timber windows were fitted post render but had an already fitted frame that he sealed with render etc and they clipped into. This is like a full time job!
    Posted By: peacebabe68The cavity wall insulation was done before we bought the house and I dont rate it anyway.

    If you can check to make sure you don't have a gale still blowing through the cavity (check on a windy day!!)

    Posted By: peacebabe68Is there a way to work out the material costs to heating running costs?
    Do you mean here the material cost of the insulation to heating cost? If so you will spend on the insulation once and the heating cost every year so you are looking at the ROI. You will need to know what your heat load is after the insulation works and then translate this into the typical annual heating cost - then you can see the pay back time for the insulation spend (ROI) You will need to know your heating load anyway so that you can size the CH.

    Posted By: peacebabe68Removing biomass from the equation puts us back to oil fired boiler or ASHP

    Don't forget LPG. Gas boilers are much cheaper than oil boilers and are more main stream which makes availability and servicing easier. If you get your heat load down enough with the insulation then any variation in the fuel cost is dwarfed by the extra cost of an oil boiler vs. a gas boiler. Other factors also kick in as the regs for oil storage are easier than for gas tanks - but then if the heating demand is low enough a couple of large propane tanks would do which as portable exchange tanks I believe have different storage regs to a fixed refillable tank.
    • CommentTimeMar 14th 2017
    I believe it's a Velfac oddity that they want the rendering done first. Other suppliers, window fitters and renderers generally prefer to fit the windows first. It's quite common to insulate and render over the outer part of the frame. I suggest you look at some other window quotes. What style of windows are you looking for? Inward opening, outward opening etc? £45k is a lot of money for windows, how many are you looking for?
    we are looking for an aluminium clad/timber window outward opening. There is a bi fold and a sliding patio door...in the house there are 13 windows, 3 doors, but i have also asked them to quote for my work studio in which there are 7 windows, 2 doors. There are also 4 rooflights not quoted for by velfac. I have asked for other quotes from other companies for the studio (that quote came in at 11,500 =vat) and may do those in timber so the house came in at £31K
    • CommentTimeMar 14th 2017
    Hmm, I bought 14 windows and a lift-and-slide door, a tilt-and-turn double door, a pair of french doors and 3 single doors to passivhaus spec for under £22,000 three years ago.

    Bifold doors are difficult to make and keep airtight over the long term, though I think there are now some specialised suppliers. Sliding seals are inherently more difficult than compression seals.
    Posted By: peacebabe68The architect has said that the house to be insulated /rendered is 70m2

    Posted By: peacebabe68in the house there are 13 windows, 3 doors,

    Posted By: peacebabe68There are also 4 rooflights

    That seems like a lot of windows and doors for a 70m2 house
    Are the roof lights must have or nice to have 'cos they are not very efficient at keeping the heat in!
    Sorry the rendering goes over 70m2 the whole house covers 225m2!
    • CommentTimeMar 14th 2017
    Posted By: Peter_in_Hungary
    Removing biomass from the equation puts us back to oil fired boiler or ASHP

    Don't forget LPG
    Don't forget with PassiveHouse or close, you won't need a space-heating system at all - just fan heater maybe. Save your equipment money - spend it on the fabric.
    • CommentTimeMar 14th 2017
    Posted By: djhIt's quite common to insulate and render over the outer part of the frame
    In fact so massively beneficial that it's essential!

    To be clear, this means bringing insulation across to master the outside face of the frame jambs and head (usually not possible at the cill), as far inboard as the hinge-pin (or equiv) line will permit. Reduce the area of poor-insulator frame that 'sees' outside air. You can do the same trick inboard as well.
    • CommentTimeMar 14th 2017 edited
    • CommentTimeMar 14th 2017
    Posted By: fostertomTo be clear, this means bringing insulation across to master the outside face of the frame jambs

    I think some Velfac windows don't have any exposed frame that can be insulated over. That may be one reason they are fussy about installation order.
    • CommentAuthorgravelld
    • CommentTimeMar 14th 2017
    I'm in a similar place @peacebabe68 with a similar sounding house, only I'm taking a lot longer than you to get going on it... but at least learning a lot from the experience on this forum.

    You're doing the right thing - investing in the building's fabric.

    I suggest going for EPS as the insulant. Kingspan is for millionaires, and is it even vapour permeable?

    Have you considered carrying the insulation over the DPC and to the foundations? Massive benefits from this, not least avoiding the disruption of laying floor insulation.

    Regards your architect, prepare for many battles with many professionals. The stuff discussed on this forum is not "normal". But it is the "Right Thing To Do".
    Hi Gravelled...Well if we can't find a builder we may be taking a long time to get this going. Seems they are in short supply at the moment. Just had a quote for the EWI from a company called wallstransform. They are coming in at 12800. When i asked him about 200mm cladding his reply as follows........ unsure where you need 200mm of insulation we use kingspan phenolic insulation which is very thermally efficient example other insulation companies use polystyrene which needs to.be twice as thick for the same insulation value will visit you If guide prices what you expected ,

    My architect is lovely. Very happy to run along with any of these ideas. Known him years so will have no troubles there thankfully. I

    The house is on top of a hill which falls away quite steeply so there are a number of changing levels. Difficult to insulate everywhere over DPM but where we can we will. Currently the concrete path has been laid higher than the DPM so that's gotta come up anyway. Obvioulsy we have to make decisions based on what's ideal, what we want to achieve and how much it will all cost! So far i am looking at a spreadsheet with numbers adding up to around £200k! We did buy the house knowing it had a lot of work to do. In many ways a lot of fun...In other ways i cant wait to get to a normal life again.
    • CommentAuthorgravelld
    • CommentTimeMar 14th 2017
    You could do it incrementally, see http://europhit.eu

    I can't see many reasons for phenolic EWI unless you are seriously tight on space, maybe others might have some ideas.
    • CommentAuthorgyrogear
    • CommentTimeMar 15th 2017 edited
    Posted By: djhI bought 14 windows and a lift-and-slide door, a tilt-and-turn double door, a pair of french doors and 3 single doors to passivhaus spec for under £22,000 three years ago

    FWIW, we bought 7 windows with electric roller blinds, one other electric roller blind; one kitchen door with manual roller blind; two tilt-and-turn hopper windows; four lift-and-slide windows (all Low-E DG) with safety barriers (made in UK !) plus six fixed TG rooflights with integral sunscreens. Cost 32,000 Euros last year. We get 12,000 Euros back in tax-relief. I am pissed off because there is no tax relief on the rooflights, even though they are part of the south windows...

    Ungrateful, north brittany :devil:
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