Mon, 25 May 2026 03:06:21 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18422 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18422 Sun, 12 Apr 2026 16:34:50 +0100 tony
Document here - https://docs.google.com/document/d/e/2PACX-1vQ2s-HB1cud4gZISwGuQvP8oIifaCVcF94ySusEaaPanqcCf4md3UPJDOKeD02Gg9MitbCVb4vXe5SW/pub]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14266 Sat, 14 May 2016 19:09:13 +0100 jwd
Cheers]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18394 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18394 Tue, 13 Jan 2026 13:51:59 +0000 D Cooke
Plasterboard and skim
125 x 50mm stud at 400 centres (vented air gap)
15mm OSB3 taped joints (functioning as a VCL amongst other jobs). Could apply another VCL over this OSB if needed/use smartply if we have to!
120mm PIR
50mm Counter batten (vented air gap)
Breather membrane
Wood cladding

The aim here is to avoid the inevitable breaks and gaps that occur when an internally applied VCL is installed around a structural oak frame. I also like the idea of a VCL that retards but doesn't 'trap'. The design idea also allows for an unbroken insulation layer that fully wraps the structure without thermal breaks (other than counter batten screws)
Ubakus tells me the condensation risk is zero. Does anyone have any thoughts? I can apply a stand alone VCL over the OSB if needed.

Thanks for any thoughts!
:bigsmile:]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18405 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18405 Sat, 14 Feb 2026 16:01:38 +0000 Victorianeco I’m looking for some guidance and shared experience as we move into the early stages of a rear extension project.
We’re proposing a single-storey rear extension, approximately 10m wide x 4m deep (c.40m²). There is a possibility it could become two storeys, but at this stage my wife and I are still undecided. Our intention is to start making progress this year, and from April we’d like to begin with the groundworks so we can at least get something tangible underway.
We are strongly considering a timber frame build, ideally on an insulated slab with underfloor heating within the main slab. At present we’re undecided on the roof design:
Pitched roof (possibly with eaves), or
Flat roof incorporating 1–2 roof lanterns
The rear elevation is likely to have two or possibly three sets of French doors, although we may also consider sliding doors.
We fully expect to engage a structural engineer for calculations, but before getting too far down that road I’m keen to understand best practice from those who have done something similar—particularly from a low-energy / green building perspective.
Some of the specific areas I’d appreciate advice on:
Insulated slab vs traditional strip foundations
Given the footprint (~40m²), would an insulated slab typically be preferable, or are strip foundations still a sensible option in this scenario?
Slab depth, insulation type and thickness
Any guidance on typical build-ups, edge detailing, and thermal performance targets would be very helpful.
Timber frame wall build-ups
From reading previous posts on this forum, a timber frame with OSB sheathing for racking strength and an EWI system externally seems to be a robust and efficient approach. I’d be keen to hear views on this and any lessons learned.
Roof build-ups
Whether flat or pitched, are there recommended best-practice details for insulation, airtightness, and moisture control?
Building in masonry is still an option, but one reason we’re leaning towards timber frame is that my 16-year-old son is currently doing a carpentry apprenticeship, and this feels like a great opportunity for him to be involved and develop his skills.
If anyone can point me towards online resources, technical details, drawings, or case studies covering slab, wall, and roof best practice—or share their own experience with a similar project—I’d be extremely grateful.
For roofing finishes, if we go pitched I’d likely consider Eternit / fibre-cement slates, possibly aluminium-clad profile sheets, or other lightweight profiled systems.
Thanks in advance for any advice or pointers—really appreciate the collective knowledge on this forum.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18228 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=18228 Thu, 31 Oct 2024 22:41:20 +0000 tony
Quiz question is, “what is missing?” And any downside

Not counting the fan grille shutters that are missing

Here is the pic https://share.icloud.com/photos/0ae8YsVF73xmIWOweyFfXaxqA]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17780 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17780 Wed, 15 Mar 2023 12:52:09 +0000 dovemw
Does anyone have any advice on best way to insulate a piled slab supported by piles for a PH project? The default by the groundworks contractors looks like there will be anti heave measures then insulation under the slab and the slab itself. Is there a solution to avoid thermal bridging where the pile connects to the slab? I assume we could insulate above the slab and then use high compressive strength insulation under the timber frame sole plate to reduce the impact of the cold bridges, is this a good solution?

(I have been looking to see if there are any discussions on piled foundations on this forum and can't find any specific to this hence creating a new discussion.)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17892 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17892 Sat, 08 Jul 2023 15:53:23 +0100 tony
Available here : - https://www.amazon.co.uk/s?k=adventures+of+an+eco+builder&i=digital-text&crid=2WMODXAZ6Q9IX&sprefix=adventures+of+an+eco+builder%2Cdigital-text%2C112&ref=nb_sb_noss]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17835 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17835 Thu, 11 May 2023 14:18:12 +0100 JayC
Can anyone recommend a professional close to the Cambridge are?
I'm specifically looking for someone who can inspect a 'green' new build and report on its design and any failings/strengths.

Some background: My son has recently moved into a new build c/w ASHP, solar PV and MVHR.
The house is constructed using, what looks like, a type of SIP panel with an additional 50mm of graphite EPS; to take render. Marketing material claimed 50% more air tightness than a traditional build, but his permeability test shows 5.41m3h @50Pa. (Technically better than BS but not really in the spirit of the development) EPC is A (for what its worth)

1st issue: His electricity bills, for hot water, seem quite high @£200 per month (2 people) He has been advised to leave the HWS flow temp at 44degc
2nd issue: The house is hot on the West side and rarely drops below 24degc and were not even close to the hottest part of the year -I feel it should have had some shading?
3rd issue: The controls are a mess - Its all based on Samsung Smart Things but none of the devices seem to communicate. He has no idea what, and when, his solar PV is generating the room thermostats are basic with no comms back to the hub, and they have installed some standalone sensors to track temp/humidity etc.

Many thanks,]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17789 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17789 Mon, 20 Mar 2023 22:49:15 +0000 CJT https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17660 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17660 Fri, 09 Dec 2022 16:37:18 +0000 tony
https://share.icloud.com/photos/0e2LzadM_vBoJ-mAxu5rUx1yg

From left to right, first three pairs of semis; note the heavy frost lines above the party walls, this is nice to see as a lot get frost and snow melting here due to heat rising through the cavity. Here it probably has the required fire packing and this is insulating the tiles from the warmth in the loft allowing more frost to form and preventing it melting.

The first building with balconies has odd frost melt on the right hand high roof, presumably due to missing insulation?

The block to the right of the pylon in the background is interesting in that there is more frost round the perimeter of its roofs indicating better insulated and less well connected to the loft. I have my suspicions as to why.

The house on the far right I think is either unoccupied or unheated, looks too perfect.

For the OCD among us have a look at the fourth house from the left and notice how the frost has melted against the adjoining house. Lots of possible reasons, heat leaking up the gable wall, or is the outside skin being warmed by poor insulation in the wall of the fifth house? The sixth house looks to be warmer than the rest.

There is more, what do you see?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17581 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17581 Mon, 26 Sep 2022 23:45:06 +0100 newcomers
purchased a new build 4 years ago and after the 1st winter we knew had a problem. Had thermal imaging survey done which showed no continuous ribbon of adhesive and either no or incorrectly fitted cavity closers. Had expert witness structural survey done which showed no dpc around doors and frames, plus issues in loft and many other defects. Went legal and now 2 years later we have reached a settlement with the developer. The sum awarded to me would cover 75% of the costs involved to do the following:

Remove all dry lining and apply ribbon of adhesive along with new skirting boards. Removed windows, doors and frames, install dpm and cavity closers. Replace carpets and redecorate.

Would I achieve similar results by removing skirting boards and using foam to seal along the bottom of boards and wall? Could I inject foam along the tops of walls on both ground and first floor?

It has been suggested to me to remove dry lining and then wet plaster instead as this would reduce heat loss even more, but unfortunately I dont think the sums awarded to me would cover enough of it.

For the windows and doors I think the only way would be to remove them all and do it properly unless anyone has any ideas?

I ask because Im worried that I will use all of the money awarded to me, plus a lot of my own money doing it the right way (full removal of dry lining etc) only to find it hasnt made much difference. Im also worried that injecting foam wont make much difference either!

Any advice would be greatly appreciated.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17580 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17580 Mon, 26 Sep 2022 21:22:15 +0100 John Pedersen I've just got planning permission for a 50m2 timber house in France. I own a few acres of forest close by, mostly Oak and some Scott's pine.

I'm wondering about chopping down a few trees to use to build the house - pine for the 6x2's to support the OSB walls, and Oak for the cladding.

I'm intending to build it as airtight as possible and have thick insulation along the lines of the passivehaus standards. This should pretty much eliminate condensation within the structure, so I'm thinking that using my own timber, untreated, might be fine.

I'm still working on the design of the house and beginning to make a tree inventory to see if this idea might work.

Any suggestions or advice would be most welcome.

Thanks.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17564 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17564 Mon, 12 Sep 2022 15:26:06 +0100 Newbuild
Essentially we have 500mm of rockwool horizontal loft insulation in an unventilated loft and where this meets the roof at the eves it shrinks down to the available rafter depth, circa 60mm minus 20mm. Unfortunaly there is no hip in the roof to accommodate a deep amount of insulation over the eves.

I have retrofitted ventilators on the wall plate since there is an over eves ventilator but it was blocked by the roof insulation initially - The insulation itself cant be carried over the eves so much since there is a cavity tray running horizontally where a double height lintel protrudes up level with the wall plate. The cavity below is 100mm full fill.

Is there anything I can do to improve this junction? I am just weighing up options, I would mostly like to avoid air infiltration down the cavity or worse down the void behind plasterboards.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542 Sat, 20 Aug 2022 13:08:32 +0100 richardelliot
We're aiming for a four bedroom highly energy efficient home. Getting Passive House certification isn't a requirement, but we'd like to be approaching that level.

We are considering using the architect that we used last time as we know we have a good working relationship with them, they are local and they have experience getting challenging planning permission applications granted (we have a tricky sight). On the downside they have very limited experience with Passive Houses. They are currently designing one for another client. As they don't have anyone qualified in the office they are using a consulting firm for advice, PHPP modelling etc.. None of the contractors they work with have built a Passive House before.

One of the other architects we're speaking to has been Passive House certified since 2010. They have done multiple new build and retrofit Passive Houses. Clearly they know how to reach Passive House standard and have relationships with timber frame companies and contractors who have achieved it in the past too. On the downside we don't know how well we'd work with them (I'd rate the relationship with your architect as the most important one of the whole process as it can be a 3yr journey together) and they are based a bit further away lack some of the local planning knowledge and convenience.

Has anyone been in a similar situation? I think my main concerns are:
1. If you use a non-Passive House qualified architect can you effectively supplement with a Passive House consultant (there do seem to be a view about and most successful PH projects seem to have one)? Or do you really need to be going with a certified architect?

2. If you go with a timber frame company that has a Passive House option (e.g. MBC) when they create the structure will they include all of the designing out thermal bridges or do you need your architect to have done that?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17438 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17438 Tue, 05 Apr 2022 11:06:47 +0100 fergoose
Is the void behind the stone necessary? or can it be up aginst the insulation like an insulated cavity?

Thanks
Fergoose]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17392 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17392 Wed, 16 Feb 2022 22:03:43 +0000 renewablejohn https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17279 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17279 Tue, 09 Nov 2021 21:23:14 +0000 alant Thoughts, personal experience very welcome.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17328 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17328 Thu, 16 Dec 2021 16:46:31 +0000 Shevek
We've specified 220 mm i-joist rafters fully filled with glass mineral wool (with 0.032 thermal conductivity) and an Intello Plus VCL to underside of rafters (with a further 25 mm batten/service zone + plasterboard)

But there are currently very long lead times for the glass mineral wool (estimated delivery March 2022), so the contractor wants to look at alternatives. One of which is a multi-foil honey comb product called Hybris between rafters and a thin multi-foil VCL (HControl Hydbrid) to underside of rafters.

HControl Hybrid + 170 mm Hybris is said to provide 0.13 u-value, and at roughly £26m2 considerably cheaper than mineral wool. And with a lead time of only 2-3 weeks. They also come with a suite of LABC certified details.
https://www.insulation-actis.com/pitched-roof.html

So, if those figures are correct, the advantages are obvious. What are the other things to consider? I'm going to list them here as people post them:]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16957 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16957 Thu, 04 Mar 2021 18:55:35 +0000 Newbuild https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17206 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17206 Fri, 24 Sep 2021 21:11:47 +0100 squowse
I'm constructing a timber cabin - exterior wall consists of (from inside to outside)

1) 9mm OSB
2) 100mm Sheepwool Insulation between studs
3) 9mm OSB
4) Glidevale TF200 Protect Breather membrane
5) Vertical and HorizontalBattens
6) Vertical Timber Cladding

Just concerned about breathability. I'm under the impression that an internal vapour control layer is required, and that OSB is about the right permeability if the joints are sealed. So proposing to do this on layer 1)

As regards the outside membrane, this should be more permeable than the internal VCL. I was thinking of gluing the OSB 3) for strength. This would seal it quite well and I'm thinking I need some holes drilled in it to give it some breathability.

I'm probably overthinking this but want to get a nice breathable air-tight structure.

Thanks
ROger]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17225 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17225 Tue, 05 Oct 2021 11:41:29 +0100 cremi I have an insulated concrete slab which I want to build up by 80mm.
It is a passive grade house extension that I need to build up to match existing house floor level.

I had originally laid battons on the concrete, then 18mm plywood as a sub floor. I had some water
ingress from a hot water cylinder which resulted in mold build up to the underside of the plywood, which I have since removed.

I am wondering whether to put in a screed or an insulated floating floor, such as kingspan panels. My floor finish will be 18mm engineered timbers.

Will the Kingspan panels work in this case? I didn't use any DPM over the concrete slab initially, but I think the issue was caused by the un-ventilated void between battons (airtight building). By eliminating the void, will this prevent any future mold build- up?

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17172 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17172 Thu, 26 Aug 2021 20:11:47 +0100 tony
https://share.icloud.com/photos/031w9VpMrTVP-wgTg91rUJRxQ]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17163 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17163 Fri, 20 Aug 2021 11:00:42 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17114 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17114 Sat, 03 Jul 2021 20:59:32 +0100 jms452
In a nut shell it is a project ran in two new build developments fitted with heat pumps, solar PV, batteries, EVs and smart hot water storage all ran by machine learning to minimise energy costs and keep the internal temperatures to the occupants wishes.

http://www.seroprojects.com/flatline-project/

I found it got most interesting from about 20 minutes when it transitioned from why we needed this and starts talking about the measures and how they work.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17067 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17067 Sun, 23 May 2021 14:37:49 +0100 wholaa https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16281 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16281 Mon, 14 Oct 2019 20:49:13 +0100 bardo
I'm looking at non celotex insulation options for the suspended timber floor made from 300mm timber ijoists. I am open to either using treated 300mm sheepswool product or a non organic insulation such as rockwool though don't want a syhthetic which off-gasses. I'd like feedback on the following please from experienced builders who have taken the same route successfully. (1) What type of insulation to use and why? (2) what to use at the base of ijoists to support insulation? (note I don't have grills on the airbricks meaning that mice could possibly enter the void underneath). (3) What to use on top of the insulation/ijoists e.g. vapour permeable membrane? (4) we have worked with an electrician to do the first fix and underfloor cables have been put inside 40mm PVC flexible hose as to avoid direct contact with insulation. Is this a good practice? (5) A concern I have is water spillage from above. Any thoughts on this? Cheers!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17025 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17025 Thu, 15 Apr 2021 18:16:20 +0100 MikeZeidler
We're building a first floor extension on a bungalow and have an existing 12 year old ground source heat system. The company that made the pump has gone bust and although it works fine and has good enough capacity, we want to upgrade to get a quieter and more energy efficient model. For the record, it's a TES (Thermal Engineering Systems Ltd) 16-1 16kW 230V/1Ph/50Hz and the tank is a Ecocat 360/200L

Consultants have suggested abandoning the ground source and moving to air source because a) the wells and ground collectors can't be inspected, b) the fittings between collection and pump won't match up and c) we could get RHI for a new system, but not the upgrade.

The idea of simply declaring the groundsource system redundant really goes against the grain. Anyone had this problem and overcome it?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11993 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11993 Thu, 17 Apr 2014 21:31:43 +0100 Ed Davies
The question is, is it OK to full-fill between the rafters up to the sarking with glassfibre or is a ventilation gap above the glassfibre, below the sarking, needed? My intuition is that the glassfibre is sufficiently vapour open that the ventilation gap is redundant but it'd be nice to be a) sure and b) able to prove it to a Scottish BCO.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16778 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16778 Tue, 03 Nov 2020 19:01:59 +0000 teach_glas
I started a thread a few months back about timber cladding on 200mm EPS EWI with single-leaf masonry blockwork as the substrate. There were a few possible solutions raised but it means getting a bit experimental and could be difficult to get engineer to sign-off on the building.

I am considering using a 200mm wood fiber board instead now as this provides much more stability to the fixings and simplifies the cladding design (you can fix the cladding batten with EWI fixing).

Only problem is now is that the projected U-value of the wall is now around 0.18 which is pretty poor considering target was 0.14.

Advantages seem to be: sustainability, fire resistance (compared to EPS), and structural rigidity for cladding.


Not sure if this is worth compromising my overall insulation... it would be a simpler build.. maybe I could use an insulating render inside, but this messes with my 'storage heater' design!


Any thoughts would be much appreciated!



:smile:]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16791 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16791 Wed, 11 Nov 2020 16:46:22 +0000 converse https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16925 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16925 Sat, 06 Feb 2021 21:53:22 +0000 bardo https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16892 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16892 Mon, 18 Jan 2021 13:52:10 +0000 Magpie I am currently researching potential construction materials as I have to avoid a lot of chemicals, such as formaldehydes, which are also contained in the glues many construction materials such as glulam, plywood etc
Brick is a safe option, but I suspect labour costs are high. I am considering a modern “log” cabin type house, but am wondering about the resale value, as I can’t afford to invest in a home that loses value upon sale. Does anyone have any views or information on resale values and construction types?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16757 Fri, 16 Oct 2020 15:55:34 +0100 nickbartleet
Thanks!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1533 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1533 Fri, 04 Apr 2008 12:28:39 +0100 Pingy
Going down the path of more is better than less approach can anyone advise whether it would be possible to have a 100mm concrete slab on top of 300mm of flooring grade EPS?

Is the concrete too thin?
Does the concrete need steel reinforcement?
Can underfloor heating pipes be cast into the concrete?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16592 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16592 Sun, 07 Jun 2020 20:58:32 +0100 teach_glas
Im not finding much help with this online, or even chatting to insulation suppliers:

My house will be single leaf 215mm blockwork with 200mm EWI. About half of the build will be clad with timber, my problem is that 200mm is to far to mechanically fix the battens for the cladding, there might be significant sagging.

Possible solution: fix a 100mm thick stud externally to block wall (within EWI layer), this way the fixing would only travel trhough 100mm of insulation to meet stud.

Anyone dealt with this kind of thing before?

Thanks a lot, any help much appriciated :smile:



J]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16681 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16681 Fri, 07 Aug 2020 00:51:37 +0100 teach_glas
Due to height restrictions etc, I'm having to put my slab 70mm below ground level.

A few details:

-single leaf block-on-flat construction
-150mm insulation above slab + floating screed
-DPM under slab and brought up taped to DPC
- EWI extending well below ground

Can you foresee any issues with having the slab slightly underground like this?

Cheers :)]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16540 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16540 Fri, 01 May 2020 21:55:00 +0100 djh
(Not long enough, I hear the crowd call)

But I've enjoyed the past three episodes of GD Oz. Peter whatsisname is much better than Kevin of that ilk, and the projects have been inspiring. The last three have been very good, IMHO.

- a no-heating part-underground house
- a bushfire-proof house in the bush
- a minimalist house]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16505 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16505 Wed, 01 Apr 2020 20:49:16 +0100 tony
You can read my full article with pics here http://tonyshouse.readinguk.org/category/the-house/]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16501 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16501 Fri, 20 Mar 2020 21:20:52 +0000 Petlyn
We have concrete wideslab flooring to both ground and first floors and as a result have installed maxi trunking beneath the first floor to accommodate all electrical wiring (single cables not twin & earth); all cables were placed in conduit, chased into the walls prior to to plastering.

We have several outlets identified for cat 5 cable - is it possible to place the cat 5 cable in the maxi trunking along with the electrical cables - probably not - if no, would placing the cat 5 cable within another conduit before placing in the trunking be an option? If no again, would placing the cat 5 cable in a conduit and then fixing above the maxi trunking be the solution? This would keep electrical cables and the cat 5 cable about 100mm apart.

Any recommendations/suggestions would be gratefully received.

Thanks folks.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16409 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16409 Tue, 21 Jan 2020 11:59:06 +0000 bardo https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16472 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16472 Sat, 22 Feb 2020 13:17:39 +0000 tony
http://www.nhbc.co.uk/Builders/ProductsandServices/TechZone/NHBCStandards/TechnicalGuidanceDocuments/92/filedownload,65388,en.pdf

This is TOTALLY UNBELIEVABLE]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16441 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16441 Sun, 02 Feb 2020 08:55:54 +0000 bardo
Rather than use wool boards, as we are for the sheepswool insulated, hemp/lime rendered internal stud walls and clay plastered rafters, I am considering foil backed plasterboard for the bathroom ceiling, walls. Is it a good idea to hermetically seal this room? And what of the floor? We have suspended timber ijoists which I will be insulating with glass or mineral wool. The plan for the rest of the home is to put a taped 18mm OSB 3 layer on top to act as a vapour check. Your thoughts welcome.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16397 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16397 Mon, 13 Jan 2020 12:58:34 +0000 bardo https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16385 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16385 Mon, 06 Jan 2020 22:18:43 +0000 bardo https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16346 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16346 Fri, 29 Nov 2019 17:45:06 +0000 Victorianeco
Essentially it's going to be a single storey extension with roof lantern.

What's the best build up?

For the floor could she even lay EPS straight on the slabs, screed on top?

Then timber frame or block on flat with EPS EWI built on the slab?

In my head I was thinking of a a basic timber wall plate attached to the existing rear wall and a flat roof with appropriate timbers for an EPDM flat roof?

The orangery will eventually house her kitchen.

Input appreciated]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16331 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16331 Fri, 15 Nov 2019 08:17:26 +0000 craigcandrews https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16334 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16334 Sat, 16 Nov 2019 15:53:17 +0000 tony
Anyone else seen anything like this?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16284 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16284 Tue, 15 Oct 2019 21:10:36 +0100 Tullich
His amendments would mean the make up is as follows:
250mm compacted sub base
50mm sand blinding
DPM
EPS layers (held back from the slab perimeter to form the ringbeam
DPM
Steel reinforced concrete

I'm struggling to find similar constructions which use the first DPM over the sand blinding. Can anyone shed some light on the accepted method vs his suggestion as above?

Thanks]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16233 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16233 Thu, 05 Sep 2019 21:36:22 +0100 debbiel
The rafters are 400mm centres and are 190mm deep. What is the best way to insulate between rafters? Best insulation to use? Do I need to leave any air gaps, or full fill? Breather membrane/vcl? External insulation not an option, so what would be best for an internal thin layer to stop thermal bridging? The work will be done by volunteers, so I'm thinking Kingspan or similar for ease of use, but all ideas welcome.
It will be finished with plasterboard internally - unless anyone has a better alternative?
Thanks in advance.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16185 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16185 Mon, 22 Jul 2019 00:22:03 +0100 Kev.k
Unfortunately redundancy, ill health, nightmare groundworks (14m x 4m retaining wall), 3 close bereavements and a lack of a mortgage have impacted my plans massively.

The retaining wall is now finished and I’m ready to start building.

I planned to use ICF blocks and DIY the build with some joiner friends, thinking this would be the best option as I’d save on labour.

When the quote came back, I realised I could have a block house built for less than the price of the blocks.

To keep cost down I looked at 140mm solid walls with EWI. It seems that BC don’t like this idea, nor do any builders I’ve spoken too. So 215mm (100mm block laid flat) make sense from a cost point of view.

I would insulate the walls myself with a timber clad finish.

I’ve read that insulated raft foundations work out cheaper than insulated strip foundations but this isn’t what I’ve found so far.

Any advice would be greatly appreciated. If I have got anything wrong I’m happy to be corrected.

I know most members are interested in building the most energy efficient houses possible. Due to my budget this isn’t a option for me unfortunately. But I’d still like to build the most energy efficient house I can.

The house is nothing exceptional. A 12.5m x 6m 4 bed detached box.

Initially it was 7.5m wide but the width of the retaining wall foundation eat into my plot.

I did finally get some good news this week regarding my plot though.

When I initially bought the plot my solicitor was shut down by the law society before he registered it in my name with the land registry. No one informed me and the guy I bought the plot off remortgaged shortly after.

As a result the land registry initially rejected my completion certificate. It only took my conveyancer 3 years to resolve. I got the call on Tuesday. :bigsmile:]]>