Rural passive house build on a farm

[Furnace]

The journey has started, but I'll need plenty of support.

Currently working with architect for a design to submit for planning. I'm intending to employ a PHPP consultant to assist and advise on the design, and have a planning consultant to help navigate the local planning shenanigans (Green Belt, but we already have a Class Q approval).

I'll be back!

[joe90]

Hi and welcome, looking forward to hearing about your project, lots of good advise here.

[Furnace]

Thanks. It's quite daunting since I'm single, children have left home so I'm flying a bit solo. I'm in no rush, so will be taking it slowly. Just as well since there are SO many decisions to make!!

[JohnMo]

Manage it in bite size chunks, make decisions once and stick with the decision.  Changing your mind later costs money and time. Try to keep the design simple, complex can look good, but is a pain to construct.  Use a build method that isn't much of a learning curve for the builder or you, if you are doing it yourself.

 

Be careful you don't make rooms to big, it's very easy to do, watch out for evening heat gain from a low westerly sun.

 

Good luck, but enjoy it. Try to get most the decision making done prior to build.

[Furnace]

Sound advice.
I've given the architect guidance that I'm not looking for something that looks good on Instagram-  I'm looking for comfort, ease of build, ease of use and maintenance, low energy use and very few bells and whistles (that will likely cause headaches down the line). I think they get my drift.

I'm not wedded to a build system, but am drawn towards MBC for the assurance of air-tightness and experience.
But there are a plethora of other decisions to be made, which is daunting. I should compile a list, but even that's daunting....

[Ferdinand]

Welcome.

 

Have you tried old episodes of Grand Designs for suitable inspiration?

 

There have been a number of practical (ie less upbutt than sometimes happens on GD) designs based around farms - I recall a couple who built one so they could move out and let their children have the main farmhouse with the farm. Farmers normally have their feet on the ground, especially when it comes to trebling the value of a small piece of land and getting a forever-house to boot.

 

Rather like a several hundred £k detached Grannexe shaped like a farm building, and with practicalities such as a North Side pantry.

 

May be worth a look. If i have time I'll do a peruse for a few episodes.

 

Ferdinand

 

[Furnace]

The design and location on the plot is coming along quite nicely and planning will likely be submitted in a few weeks. In the meantime, I'm trying to shortlist suppliers/manufacturers of the more expensive items that will be needed.

• Main timber frame
• Windows/doors
• Timber external cladding

Any and all suggestions and experience would be most welcome.

Mark

[IanR]

On 27/09/2022 at 19:23, Furnace said:

(Green Belt, but we already have a Class Q approval).

 

On 15/12/2022 at 18:46, Furnace said:

The design and location on the plot is coming along quite nicely and planning will likely be submitted in a few weeks.

 

Hi @Furnace, a belated welcome.

 

Once you have some success with the planning app, please come back an outline your walk from Class Q to full planning, especially as it seems you hope to site the new build in a different location to the agricultural building (if I've understood correctly).

There's a few Class Q builds on the forum and a couple that have gone to full planning after securing a Class Q Approval. It's good to hear different experiences.

 

On 15/12/2022 at 18:46, Furnace said:

• Main timber frame
• Windows/doors
• Timber external cladding

Any and all suggestions and experience would be most welcome.

 

I've now been living in a Class Q conversion of a cow shed for five and a half years, built mostly to PassivHaus principles, but without certification.

 

I have an Advanced Foundation Technology Ltd. insulated raft, with a Touchwood Homes I-Joist frame, designed and engineered by Cullen Timber Design and insulated with blown cellulose fibre.

 

I'm not sure if Touchwood Homes are still running, but the two brothers (Reuben & Adam) that were involved in my build are still involved with Passivhaus builds via https://mango-projects.co.uk/our-passivhaus-build-method/ and https://wilkinsonpassivhomes.co.uk/

 

I've not found the build method they've developed with Cullen Timber Design offered by anyone else, but can whole-heartedly recommend them. It's a very cost effective way of easily achieving Passivhaus performance levels.

 

For window and Doors, I went with Internorm, but was very close to selecting Norsken. For cladding I went with a European Oak, featheredge cladding on the upper half, for a zero maintenance finish that tied in with an adjacent barn, and a board-on-board PAR Sapele vertical cladding on the lower half, that does require oiling every few years, on the lower half.

 

[Furnace]

Thanks Ian. I'll certainly post my experience of the journey from Class Q to full planning.

My architect is a fan of Norrsken windows, although I found them a little poor on build tolerances when I saw them at the NSBRC, and a couple of the designs had no compression seal on the weather side of the euro locking mechanisms.

Thanks also for the Mango/Wilkinson link. I'll add them to MBC and Eden Insulation as possibie frame suppliers.

Cheers

Mark

[Furnace]

On 24/12/2022 at 13:53, IanR said:

I have an Advanced Foundation Technology Ltd. insulated raft, with a Touchwood Homes I-Joist frame, designed and engineered by Cullen Timber Design and insulated with blown cellulose fibre.

I spoke with Rob Cullen today. He explained that they design timber frames and have a preferred timber mill in Gloucester that machines and prepares the parts to his design. These parts are then shipped to the site and erected by the customer's choice of builder.
Is that the route you followed? I had originally been intending to pursue an MBC- style (pre-made panels) path, although may have site access issues depending on panel size since I'm at the end of a half mile drive with overhanging trees and some 90deg bends, so the smaller vehicles possible with the "stick construction" approach may be better.
 

[Furnace]

Progress is being made on the project and the planning application is due to be submitted in the next week or so. The only thing left to finalise is the shading requirement to avoid excessive solar gain, and I soon should have those details back from the PHPP consultant.

3d.pdfelevations.pdfplan.pdf

Next major step I'm researching is build system, although I'm already pretty sure it will be timber framed due to low embedded energy and speed of erection. I'm attracted to factory built panels that are craned into position, although since there may be some issue with artic access down a 1/2 mile drive with overhanging trees I'm also open to a more labour intensive system of a kit comprising precut plates and studs that are assembled on site, but delivered on smaller vehicles.

Companies I have in mind for prefab are MBC and Eden Insulation? Anyone have experience of Eden? I understand they're used by Justin Bere and Ecoarc.
For "stick kit", has anyone any recommendations?

All comments welcome
 

[IanR]

26 minutes ago, Furnace said:

I spoke with Rob Cullen today. He explained that they design timber frames and have a preferred timber mill in Gloucester that machines and prepares the parts to his design. These parts are then shipped to the site and erected by the customer's choice of builder.
Is that the route you followed? 

 

Mine came as a frame package with Touchwood Homes, so Touchwood "introduced" CTD to me and I worked with them and Touchwood to develop the Frame. Touchwood then took delivery of the frame at my site and erected it on the insulated raft I'd contracted separately with AFT.

 

CTD, Touchwood and AFT were all first class.

 

There's a few image of my frame in the following thread.

 

 

 

32 minutes ago, Furnace said:

may have site access issues depending on panel size since I'm at the end of a half mile drive with overhanging trees and some 90deg bends, so the smaller vehicles possible with the "stick construction" approach may be better.

 

I believe there was an option to pay a bit more for delivery on smaller vehicles, but my frame was delivered on a couple of artics. I knew they wouldn't be able to get up my track, so they parked in a layby opposite and we unloaded with a loadall.

 

[IanR]

24 minutes ago, Furnace said:

Progress is being made on the project and the planning application is due to be submitted in the next week or so. The only thing left to finalise is the shading requirement to avoid excessive solar gain, and I soon should have those details back from the PHPP consultant.

 

Looks very nice. But that South facing glazing is going to be an issue. I'm assuming there are good views, so you're going to want to keep the glass and mitigate it as best you can.

[Russdl]

@Furnace Indeed it looks very nice but I’m surprised at the form factor if a Passivhaus consultant was involved and as @IanR says you’ll need to watch out for that south facing glazing.
 

Do you have shading/blinds planned for that? if not and it’s built to passive standards it’ll get mighty hot in there in the summer. 
 

Oh, and fill the whole south facing roof with PV whilst the scaffolding is up. Daft not to IMHO. 
 

Edited February 13, 2023 by Russdl
Added the PV bit

[Nickfromwales]

Regarding 'unwanted' solar gain;

You can do away with moving parts, such as blinds etc, simply by employing solar reflective glazing. This approach is embraced by the PHT and will be a far more sympathetic approach to a problem often inflated.

Cooling in summer is far more costly to mitigate against, in a PH, than a resultant requirement for some mitigatory winter heating ( eg to combat the reduced solar gain ). 

I've consulted for clients, building their own homes, from PH to PH+ and above, and these issues can be easily resolved with some care, diligence, and an overall better understanding of "what can go wrong". 

 

Plenty of folk on here have also been kind enough to share their varying experiences, warts and all, so a good read up here can stand you in very good stead.

[Furnace]

Thanks @IanR @Russdl @Nickfromwales

We'll definitely will need solar gain mitigation on the South elevation, but haven't yet shown it in the designs. The current view is to include brises soleils and don't yet know how much/many will be needed.

@NickfromwalesReflective solar film is another route that could be used, although I'm uncertain about the "tint" when looking out from within? Any resources/recommendations to research this further?

Thanks to all for helping on this rather daunting journey.

Mark

[Iceverge]

hi @Furnace, a belated welcome. 

 

Really nail how much money you have to spend.

 

Similar situation here.  Passive house on a farm. Tricky access.  Went through 3 sets of planning while dealing with some very slow and expensive land registry issues. in hindsight maybe 4 would have been even better!  Spent the time getting to grips with PHPP, thermal bridging, airtightness, costings etc.  I came to the conclusion a simple passive house was the cheapest to build so long as you avoided an expensive heating system. 

 

 

We went from a double house like yours to a simple square farmhouse shape, no valleys to leak, no difficult thermal bridges to deal with at single vs two story intersections. Cheaper to built and less costly to heat etc etc. 

 

It went from 200m2 to 225m2 to 185m2.  The budget was fixed at €300k as the bank wouldn't give us a cent more.  Had we tried to build one of the first designs we'd have run of cash or ended up super stressed and with a poor finish. As it was we ended up with everything spent but also with curtains hung and beds dressed. 

 

It's a nice design but I'm thinking £500k might not finish it out.  

 

 

 

 

 

 

 

[Nickfromwales]

On 14/02/2023 at 10:21, Furnace said:

@NickfromwalesReflective solar film is another route that could be used, although I'm uncertain about the "tint" when looking out from within? Any resources/recommendations to research this further?

Sentinel by 3M is one, iirc. Try to get this factory applied to the glass vs retrofit. Apply the same tint to non-problematic glass on the same elevations, but use non solar-reflective 'tints' for those, eg so you can have mixed types but the solar reflective panes don’t stand out.

[Kelvin]

It looks nice but it’s not the cheapest build. The double roof adds complexity and therefore cost. Brise soleil can be very expensive to add to a building. It also looke pretty big. Does it need to be as large. Our house has ended up a bit bigger than we planned (202m²) but much smaller than a lot of self-builds. 
 

I was in a new barn style yesterday. Big south facing windows. No solar gain mitigation. The room was very warm. This was in Perthshire. They were saying it can get a bit unbearable in really hot summer days. The upside is their heating has hardly been on even through winter. 

[Furnace]

On 14/02/2023 at 11:35, Kelvin said:

t looks nice but it’s not the cheapest build. The double roof adds complexity and therefore cost. Brise soleil can be very expensive to add to a building. It also looke pretty big. Does it need to be as large. Our house has ended up a bit bigger than we planned (202m²) but much smaller than a lot of self-builds.

You're absolutely right. The design is driven by the slightly triangular plot shape/size/orientation/views rather than optimum PHPP or build cost efficiency.(the design below is an earlier iteration)

I've kept  the size down to 250m² which seems about right for both the plot and for the local market expectations for houses in this type of location. I experimented with making it a smaller and 3 beds, but it seemed to compromise too many other aspects and I think I'm OK with the size now.

On 14/02/2023 at 11:17, Nickfromwales said:

Sentinel by 3M is one, iirc. Apply the same tint to non-problematic glass on the same elevations, but use non solar-reflective 'tints' for those, eg so you can have mixed types but the solar reflective panes don’t stand out.

Good idea. I'll see if I can get some samples.

 

On 14/02/2023 at 10:58, Iceverge said:

We went from a double house like yours to a simple square farmhouse shape, no valleys to leak, no difficult thermal bridges to deal with at single vs two story intersections. Cheaper to built and less costly to heat etc etc

Yup, the valley is not my favourite feature but the architect is advising that it shouldn't be seen as a deal-breaker. As mentioned above, the shape is largely driven by the plot.

However, all suggestions are welcome at this stage. It's far cheaper to make amendments on paper than when building!! This forum is so valuable for those who don't regularly build houses.

Mark

 

[Furnace]

Planning is about to be submitted and the consultant has sprung upon me a requirement to demonstrate/document that >10% of the new build's energy will come from renewables. The PHPP model shows a Heating Demand of 11kWh/m²/a and the TFA is 233m² so an annual heat demand of ~2500kWh. According to the Energy Saving Trust calculator, an 8kW PV array in my location, orientation and elevation generates about 7500kWh per annum. Is this an accepted approach, or is it more typical to have a full Design Stage SAP performed?

[Marvin]

2 hours ago, Furnace said:

Planning is about to be submitted and the consultant has sprung upon me a requirement to demonstrate/document that >10% of the new build's energy will come from renewables. The PHPP model shows a Heating Demand of 11kWh/m²/a and the TFA is 233m² so an annual heat demand of ~2500kWh. According to the Energy Saving Trust calculator, an 8kW PV array in my location, orientation and elevation generates about 7500kWh per annum. Is this an accepted approach, or is it more typical to have a full Design Stage SAP performed?

Hi @Furnace

 

You can always use the PHOTOVOLTAIC GEOGRAPHICAL INFORMATION SYSTEM:

https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html

 

Mark the exact position of the property on the map first and then fill out details on the right.

 

Good luck 

 

Marvin

 

Edited February 21, 2023 by Marvin

[Furnace]

Thanks @Marvin I'd heard of that site but couldn't find it for looking....

It shows similar figures to the Energy Saving Trust version - 8086kWh with a 267kWh annual variability.

I hope that satisfies the planning consultant, and I don't need another bolt-on consultant to produce a more formal document. I've already been stung with consultants for ecology, environmental, heritage, inside leg measurement......

[SteamyTea]

51 minutes ago, Furnace said:

It shows similar figures to the Energy Saving Trust version - 8086kWh with a 267kWh annual variability.

Did that take the shading into account, seems that the majority of the modules will be shaded for half the year.

[Susie]

I know you’re doing PHPP but have you done your Part O modelling yet. You need to do that ideally before the planning.