Dreadnaught

I looked into mezzanines briefly because the seller of my property wanted to prevent me from having one (long story). Could there be a building regs issue in relation to the minimum ceiling height needed for both the mezzanine space and the residual space beneath it. In my case this was my clinching argument for my seller. I could not feasibly squeeze in a mezzanine while meeting minimum ceiling height requirements, so he was content with my high ceilings. How high is the space you will be dividing (you mention 5m)? What will be ceiling heights of the new space and the space left beneath? (I am new to this building lark so could be completely wrong.)

@lizzie thanks. Can I just check that it is 400mm of blown-cellulose insulation in your roof? Did they come along with the blowing machine and cut disks into your ceiling to blow it in? Its not some sort of cellulose batt that they used? It does seem a bit odd to me that they would go through palaver of bringing the cellulose blower to site just for the roof. Good point about the ceiling service-void and downlighter. I must remember to watch out for that.

Thanks @Thedreamer. Yes having read a little about it, Protect VC Foil Ultra does sound like a good product, assuming of course that it is well installed and not punctured. It has embedded tapes at its edges but the manufacturer recommends it also be taped at the edges and joints (double taping) to ensure even higher levels of airtightness. I have asked MBC if they routinely do this.

Fair challenge @Nickfromwales. Personally, sound proofing is important to me. I like peace and quiet and the location of plot is prone to occasional raucous May-Week and bonfire-night parties, etc. And when I heard some time ago @JSHarris saying, presumably half in jest, that he would struggle to hear a Chinook throbbing overhead through his 300mm of WarmCel, I liked that the sound of blown cellulose very much. And I do concede that the timber studs that bridge directly through the Earth wool to the PIR will be channels for sound conductance. However, as well as the PIR in the section above there is 140mm of Earthwool in the walls too. Isn't that like Rockwool, which is used for sound insulation in internal walls? Moreover, is not the main source of sound ingress into a home that which comes from the windows rather than through the walls? Wouldn't upgrading from double to triple glazing have a bigger impact on sound proofing £-for-£ than spending 30% more on Warmcel in the walls? And wouldn't attention to good airtightness (which I understand has a big impact on quietness too) also make a big difference? I am happy to be contradicted.

Your usual observation is very welcome. Through your repeated emphasis on the such matters I have learnt so much. Here's the conundrum. In my design, most of the walls of my bungalow will be shaded by an overhanging simple pitched slate roof. Thus, sun's energy that could risk overheating in the summer predominately falls on the roof. Now here's the key part. The section I showed above is only for the walls, the roof is different. The roof system that MBC specifies to go along with the 140mm open stud wall system has 400mm of blown-cellulose insulation (see below). Thus, I am putting the cellulose in the place it is most needed for enhancing decrement delay, the roof. Thus I am getting the best of both worlds, while also reducing panel bulk, and saving the 30% price premium. Am I right? From MBC again …

Yes, @PeterStarck, you are exactly right. I suppose the advantages of the 300mm double-stud over the 140mm open are: Improved decrement delay, as @JSHarris rightly says above. More on that in the next post Improved sound proofing In some nebulous way that I cannot put my finger on, less cold bridging. (I am aware that a U-value (as compared with, for example, a λ value) should take into account but I have feeling I am missing something here) Less carbon embodiment Have I missed anything?

Oh, if only! It is an admired tree in a conservation zone, and nigh-on worshipped by the neighbours. It has already been trimmed: a crown lift by a proper tree surgeon and guided by an arboricultural method statement. Yes, one of those baby telehandlers might just fit or one of these off-road fork lifts:

Good point about steels. Have not got to the detailed frame design quite yet. I guess that will be in about March.

Quite right, @Russell griffiths, single storey. But I lack the glorious expanse of your truly lovely site (nor to mention your vast and wonderful wildlife pond)! On mine, the first limitation is that there is nowhere to site a crane as it is surrounded by buildings, trees and crotchety neighbours. The second is that the entrance gate is obstructed by the low branches of an overhanging mature chestnut tree. The third is that there is little manoeuvre room inside the gate nor, crucially, on the outside in the access road. Having seen a telescopic forklift being (skilfully) driven around @vivienz site, I doubt even it would fit in the cramped confines of my site. I can easily see the lorry carrying my frame stopping at to the end of the service road, some 40m away, and then each panel being carried or wheeled on dollies (possibly forklift) down the road and squeezed through the gate on to site, with the height restriction being the limiter. I had one frame company come to site and another looked carefully at it on Google street view, supported by some of my photos . Both were concerned about the access. One upped their quote by a few thousand because of it, saying they could find a way by making panels smaller, etc. The other did not quote. Anything I can do to make the panels smaller (by choosing 140mm over 300mm, for example) helps I think.

Here you go (from MBC) …

@vivienz haha. OK: The reasons for choosing 140mm wall system over 300mm twin stud: My site has restricted access and the craning of panels is likely to be severely limited and may be impossible, at least with a big crane like the huge one on your site. The panels will likely need to manhandled into position. The 140mm system is far lighter and less bulky A frame using the 140mm system is about 30% cheaper (excluding foundations) and my build is being planned with one eye on saleability

I wonder, has anyone here used the MBC open panel 140mm wall system (as compared with the 300mm twin stud)? I know quite a few on here have used the MBC 300mm passive-house twin-stud wall system but for a range of reasons* I am thinking of specifying the open panel 140mm wall from MBC instead with external-wall upgrade to U-Value 0.11W/m2K. I have some questions about the airtightness with the open panel system using the Protect VC Foil Ultra airtightness layer. (* If anyone is interested in the reasons I would be happy to explain.)

A BBC Radio programme on modular, factory-built houses. Quite interesting. "Does the house building industry need to change? Manuela Saragosa meets the disruptors, the companies trying to transform how the vast majority of residential property is built. Across the country new factories are springing up - in a bid to manufacture our homes in much the same way as we do our cars. The risks are huge." "Significant investment is required to get things moving and demand for these new homes has yet to be tested. But the disruptors claim that the house building industry must modernise or die. Productivity is falling and traditional skills are in short supply - something that is likely to get worse as immigration reduces. Other countries, too, already build huge numbers of homes off-site, claiming that this results in quicker and cheaper construction. So, just how many of the hundreds of thousands of homes that we need to build might end up being factory produced?" http://www.bbc.co.uk/programmes/p06w8yvf

After the Christmas hiatus, I am finally getting around to placing the newspaper ad. To my pleasant surprise, the cost has dropped by a third since before Christmas. Unexpected but welcome.

Now that I have finally bought a plot, to get the new planning application through and start the build (and a BuildHub blog with it).

I was thinking the same for my build. My concern about pocket doors is that I think the pocket compromises sound insulation for that section of the wall. I would therefore only put them in locations where compromised sound insulation isn't going to cause a problem.

Interesting article. Choice quote (my emphasis): "The government is understood to be preparing to announce a market-based replacement to the export tariff early in the new year, which would write the rules for how energy suppliers could buy the excess power, though they would not be mandated to do so."

Yes, good point. I think that I heard a figure of 80-years mentioned as the expected longevity of a house built today. I think it was from this podcast: https://www.houseplanninghelp.com/hph233-how-to-choose-a-construction-system-for-a-house-build-with-mike-hardwick/

Welcome Tamara! Where about's is your build?

With a 5A circuit, do the sockets use round pins? Does one need to replace the plugs on side lamps accordingly?

@Nickfromwales forgot his mince pie! Unlike him I would imagine.

The 44dB is quite surprising too. Does the new model have any pumps within?

Sorry to change the subject slightly, but I wonder why anyone has not considered using blown cellulose in interior walls. I visited a lovely Touchwood build in Suffolk recently that will do exactly that. Is it a matter of cost I wonder? Or perhaps the concern of the circular holes required? Any thoughts?

Its fascinating how there really is no one-size-that-fits all. It depends so much on the individual circumstances. Its surprisingly subtle. Its why pros like @Nickfromwales take such care to look at all the parameters before recommending a complete solution.

Yes I found that too. E10 (and to a lesser extent even E7) is not supported by even most electricity suppliers it seems. Some do, so if it interest you then you can find a company that will if you persevere. Having an E10 electricity meter installed can also take a bit of research too.