Rookies diving into the passive house deep end

[Jake Smith]

Hi All,

I've been gleaning info from this forum for a while. We just got permission granted for a passive house on the welsh boarder. Woop!

I'm a structural engineer and my wife is a project manager so we thought we'd give a self build a go... we're very aware of how narrow our fields of knowledge are though so we would be very grateful for any advice along the way!

I specialise in large engineered timber structures so happy to help if anyone needs any CLT/glulam advice.

Cheers,

Jake

[JohnMo]

Welcome.

 

Are you doing a timber structural for this build?

 

How are you heating the house?

 

Are you building yourselves or getting someone to do it for you?

 

[IanR]

Hi Jake, welcome!

 

Sounds like you could be an asset to the Forum, and hopefully you can pick up some titbits along the way.

[joe90]

Welcome to THE self build forum, lots of real world advise here (been there, done that ) ask away and I am sure others will be grateful for your advise as well. Can’t wait to see plans and pictures.

Edited May 15, 2022 by joe90

[Nickfromwales]

Bonjour, as we say in Wales.

Welcome aboard. You'll be a welcome feather in the BH cap  

[BlackMountainBuild]

Hi Jake congratulations on getting permission - we are in the planning process for a eco house not far from Hay on Wye on the Herefordshire (just) side of the border. Good luck with the build.

[MikeSharp01]

Hi and Welcome to the forum, we started our Passive house road about 6 years back and have been building, basically on my own - part time, for the last 4 years. We had to learn lots - day job is semi retired academic, about everything. We have learned loads. Here are our bullet points:

 

• The devil is in the detail - in PH building the details really matter.
• Cheque book build aspects (we have had very few trades on site - the slab pour and the roof slating only so far) still need to meet the detail level so watching like a hawk.
• Get a good architect aboard, it does not matter if they don't have PH experience provided you like their prior work, you know your stuff and can run the PHPP across the ideas as they have them to keep their design feasible. Ours did a great job, as I stand in it now, but we had to knock it about a lot to keep it feasible as a PH - glazing size / orientation, passive ventilation. Not to mention achievable on our budget.
• Ensure (easy for you) great integration between SE / architect and build a good relationship with the SE. We let our architect use their chosen SE which worked well for the most part and we have been back to the SE much more that to the architect over the build because of issues here and there.
• Decide on what you want and stick to it. We have built what the architect drew and the SE made work, +/- a few mm, and made no changes because of the costs / implications of changes. That is not to say we won't change aspects of the internals but once you get going these things get increasingly costly. (2 edged sword for you as you probably do well out of clients changing their minds but once you have the UFH in the slab moving internal walls plays hell with any zoning...)
• Enjoy it - it won't all be fun and try not to play 'Grand designs bingo' along the way EG Have some children, run out of money, get divorced, have your main contractor go into liquidation....

 

 

[TerryE]

49 minutes ago, MikeSharp01 said:

Get a good architect aboard, it does not matter if they don't have PH experience provided you like their prior work,

 

On this one, a few of us have gone down a dissenting route and have been successful at it. 

 

I did the overall design for my house myself and spent a lot of time on the 3D visualisation to make sure that the internals worked as a whole. I then used a decent local architect technician to draw up the set of plans for planning submission, and put the money that I would have spent of architects fees into our TF and passive foundation by subcontracting a decent custom build TF passive house specialist firm (in our case MBC, though there are a few to choose from).  I did all of the design validation myself.  

 

To be fair, I had recently retired when we started the build, so I could invest the time in doing the research and getting on top of all the issues.   I do disagree with Mike on "PH experience doesn't matter".  If you are going to invest in an architect's services then he or she should be competent to do what you require: although passive house design is any more difficult than classic UK build, IMO, it is just very different.  For example, it is really hard achieving passive class performance with conventional foundations + beam and block floor + block and brick leaf walls.  We used a warm slab (that is a floating reinforce slab with UFH in-slab on a structural EPS bed + twinwall TF with blown cellulosic filler: this technique achieves passive-class almost by design. 

 

Anyway have a browse of some of the blogs, and do your research. 😊

 

[MikeSharp01]

34 minutes ago, TerryE said:

I do disagree with Mike on "PH experience doesn't matter".  If you are going to invest in an architect's services then he or she should be competent to do what you require: although passive house design is any more difficult than classic UK build, IMO, it is just very different. 

Having spent time in your home I agree it can be done very well without an architect and I would not suggest using an inexperienced PH Architect unless you were confident in your understanding of PH requirements. I had a year of sabbatical to do all the homework, took the PH planning course, read everything on the predecessor site to this one, and got all the construction details I wanted in my head. We had a conundrum - we spoke to 5 architects 2 with PH experience and the rest not. Sadly it was clear that we could not work with several and we got down to two, one with PH and one without. The one without PH was up for the opportunity to learn, were open to my helping wrangle the design as it evolved - including not charging for rework if aspects were not PH compatible and we really liked their work so we went that way.

 

In the end it is always horses for courses.

 

Mike

[mike2016]

See if you can sign up for an PHPP Designer course - online or in person. Good foundation.

Visit a Passive House if any open days still exist? 

Housebuilders Bible 14th edition or greater (book)

This Forum

1/2 day or 1 day airtightness course, taping and sealing hands on should be part of that

Visit NSBRC - Swindon & any of the big housebuilding / home exhibitions to talk to exhibitors about MVHR/ASHP etc

Don't leave chocolate on top of your laptop lid - it melts....! 

Best of luck! 

[MikeSharp01]

20 minutes ago, mike2016 said:

See if you can sign up for an PHPP Designer course - online or in person. Good foundation.

Visit a Passive House if any open days still exist? 

Housebuilders Bible 14th edition or greater (book)

This Forum

1/2 day or 1 day airtightness course, taping and sealing hands on should be part of that

Visit NSBRC - Swindon & any of the big housebuilding / home exhibitions to talk to exhibitors about MVHR/ASHP etc

Don't leave chocolate on top of your laptop lid - it melts....! 

Best of luck! 

Yes did several of those:

 

• PHPP designer, the software was free excellent training in thinking it all though. I was on he course with a couple of people from a big house builder who were tasked with doing a few PH's although I am not sure they felt they (PH's) had a future in their corner of the market.
• Did a couple of PH visits with our local AECB (Association for Environment Conscious Building) group, good grounding and very motivating.
• Did an air tightness day with AECB as well.
• Swindon was not a thing then but did go the national house building show at NEC (twice - with different Agendas) to gather product details - windows, appliances, clever flooring...
•  On the chocolate front I find it does not stick around in the air long enough to melt - once I see it I eat it!

[SteamyTea]

18 hours ago, MikeSharp01 said:

On the chocolate front I find it does not stick around in the air long enough to melt - once I see it I eat it!

I defer to the greater knowledge of Mick Jagger and Marriane Faithfully when it comes to chocolate. Not touched the stuff since June, 1986.

[MikeSharp01]

19 minutes ago, SteamyTea said:

I defer to the greater knowledge of Mick Jagger and Marriane Faithfully when it comes to chocolate. Not touched the stuff since June, 1986.

That is not a great thought to hit you on a Saturday morning - but I have to praise your fortitude in staying away from it for 36 years. I manage a chocolate free lent each year and that is about all my abstinence tenacity will take.

[SteamyTea]

Just now, MikeSharp01 said:

I manage a chocolate free lent each year and that is about all my abstinence tenacity will take.

Every year, I set myself a new years challenge. They do not have to be serious, or start on Jan 1. I don't tell people what they are until they notice. Some have lasted decades.

Giving up chocolate was because of an alergy to it.

[joth]

1 hour ago, SteamyTea said:

Every year, I set myself a new years challenge. They do not have to be serious, or start on Jan 1. I don't tell people what they are until they notice

Which year was it that the challenge to become a SI unit pedant?

We certainly noticed that one 😆

[Adrian Walker]

If would suggest that you find an architect or architectural technician that has some experience and knowledge of PH design. Most don’t and if they don’t understand the 5 Pillars of PH design then you will spent a lot of time and money educating them. 

[SteamyTea]

24 minutes ago, joth said:

Which year was it that the challenge to become a SI unit pedant

As soon as I started kleuterschool, as they did it right.

[MikeSharp01]

11 minutes ago, Adrian Walker said:

If would suggest that you find an architect or architectural technician that has some experience and knowledge of PH design. Most don’t and if they don’t understand the 5 Pillars of PH design then you will spent a lot of time and money educating them.

Ours, without PH build experiance, was very bright and willing to learn and if you think about it every Architect will have made their first PH without any experiance. Also we found that the PH experienced architects we interviewed were too cautious and so had, in our view and certainly not to denigrate them, somewhat limited horizons as they automatically kept their ideas in the PH envelope and so did not offer anything really 'out there' which we thought our design needed to be. 

[Adrian Walker]

16 minutes ago, MikeSharp01 said:

Ours, without PH build experiance, was very bright and willing to learn and if you think about it every Architect will have made their first PH without any experiance. Also we found that the PH experienced architects we interviewed were too cautious and so had, in our view and certainly not to denigrate them, somewhat limited horizons as they automatically kept their ideas in the PH envelope and so did not offer anything really 'out there' which we thought our design needed to be. 

 

Congratulations of finding an open minded and willing to learn Architect 🙂

[Nickfromwales]

1 hour ago, Adrian Walker said:

 

Congratulations of finding an open minded and willing to learn Architect 🙂

Yup. Seems Russian roulette out there tbh. There is more demand than satisfaction, now that the UK had opened its eyes to the better way to build eg fabric first.
 

It used to be “kitchen first”, insulation if there’s money left over from buying the granite worktops 😐. I’ll admit when I first started plumbing the answer to a cold draughty house was bigger rads bigger boiler. . I’m a changed man lol. 

[Jake Smith]

Hi All,

 

Many thanks for the warm welcome! I am very sorry, I only just realised that I had replies! 

[Jake Smith]

On 15/05/2022 at 19:26, JohnMo said:

Welcome.

 

Are you doing a timber structural for this build?

 

How are you heating the house?

 

Are you building yourselves or getting someone to do it for you?

 

Hi JohnMo,

 

I am shamefully not doing structural timber for this build. We are down a long and winding farm track so prefab was impractical. I am friends with a very good mason so we are using cavity construction with 300mm of mineral wool batts.

 

Space heating will be via post heating of the MVHR using a hot water feed. Water will be heated via an immersion element. We have been quite purist in the design so I am not anticipating much demand based on the PHPP calc.

 

I am acting as main contractor and using local subbies. Hopefully this will save us some money and allow me to ensure my PH details are adhered to... haha. I will fit bathrooms and kitchens etc myself.

 

 

 

 

[Jake Smith]

On 20/05/2022 at 08:33, BlackMountainBuild said:

Hi Jake congratulations on getting permission - we are in the planning process for a eco house not far from Hay on Wye on the Herefordshire (just) side of the border. Good luck with the build.

Hi BlackMountainBuild,

Great, just down the road! There have been a few interesting eco and passive builds in the area of late. Hopefully there will be many more! The architects who helped us with our passive design (Arbor) delivered a passive house in Clifford which might be even closer to you. Best of luck with your planning app

[Jake Smith]

On 20/05/2022 at 09:27, MikeSharp01 said:

Hi and Welcome to the forum, we started our Passive house road about 6 years back and have been building, basically on my own - part time, for the last 4 years. We had to learn lots - day job is semi retired academic, about everything. We have learned loads. Here are our bullet points:

 

• The devil is in the detail - in PH building the details really matter.
• Cheque book build aspects (we have had very few trades on site - the slab pour and the roof slating only so far) still need to meet the detail level so watching like a hawk.
• Get a good architect aboard, it does not matter if they don't have PH experience provided you like their prior work, you know your stuff and can run the PHPP across the ideas as they have them to keep their design feasible. Ours did a great job, as I stand in it now, but we had to knock it about a lot to keep it feasible as a PH - glazing size / orientation, passive ventilation. Not to mention achievable on our budget.
• Ensure (easy for you) great integration between SE / architect and build a good relationship with the SE. We let our architect use their chosen SE which worked well for the most part and we have been back to the SE much more that to the architect over the build because of issues here and there.
• Decide on what you want and stick to it. We have built what the architect drew and the SE made work, +/- a few mm, and made no changes because of the costs / implications of changes. That is not to say we won't change aspects of the internals but once you get going these things get increasingly costly. (2 edged sword for you as you probably do well out of clients changing their minds but once you have the UFH in the slab moving internal walls plays hell with any zoning...)
• Enjoy it - it won't all be fun and try not to play 'Grand designs bingo' along the way EG Have some children, run out of money, get divorced, have your main contractor go into liquidation....

 

 

Hi Mike,

Thanks for the advise, that is a really useful list. We will be giving Grand Designs a wide berth haha! 

I am doing the construction drawings now and incorporating a ludicrous amount of detail. There is a wealth of information out there for good practice passive house detailing but it certainly takes some time and brain power to gather, assess, adjust to suit and incorporate it into a real project. If I were sensible I would have an architect do this! We will get it checked by an architect to pick up my inevitable clangers though... 

I think our biggest challenge (as you mention) will be working with the subcontractors to ensure that the details are understood and correctly implemented. They are mostly friends which will either make this easier or much much harder.

We are currently trying to select a window provider, I think The Green Building store are the front runners. Who did you use?

Cheers,

Jake

 

 

 

[Jake Smith]

On 20/05/2022 at 10:39, TerryE said:

 

On this one, a few of us have gone down a dissenting route and have been successful at it. 

 

I did the overall design for my house myself and spent a lot of time on the 3D visualisation to make sure that the internals worked as a whole. I then used a decent local architect technician to draw up the set of plans for planning submission, and put the money that I would have spent of architects fees into our TF and passive foundation by subcontracting a decent custom build TF passive house specialist firm (in our case MBC, though there are a few to choose from).  I did all of the design validation myself.  

 

To be fair, I had recently retired when we started the build, so I could invest the time in doing the research and getting on top of all the issues.   I do disagree with Mike on "PH experience doesn't matter".  If you are going to invest in an architect's services then he or she should be competent to do what you require: although passive house design is any more difficult than classic UK build, IMO, it is just very different.  For example, it is really hard achieving passive class performance with conventional foundations + beam and block floor + block and brick leaf walls.  We used a warm slab (that is a floating reinforce slab with UFH in-slab on a structural EPS bed + twinwall TF with blown cellulosic filler: this technique achieves passive-class almost by design. 

 

Anyway have a browse of some of the blogs, and do your research. 😊

 

Hi Terry,

 

It is reassuring to hear that you have been successful doing the design yourself! I keep having pangs of crippling self doubt.. I have done the vast majority of the design myself but we did manage to persuade a very good PH architecture practice to sense check the design at various stages on an hourly basis. Helps me sleep.

 

We were initially going to use the insulated raft foundation route too but the initial quotes I received were alarming. We also have a couple of point loads which were requiring the raft to be 300mm deep in places. So in the end, we have opted for thermally broken strip footings. It will not be as thermally efficient as your raft but it should get us the performance we need as we have a very good inherent form factor. 

 

Cheers,

 

Jake