Green Building Forum - Choosing an architect for an energy efficient (passive?) new build Tue, 19 Dec 2023 06:43:59 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297237#Comment_297237 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297237#Comment_297237 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?]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297238#Comment_297238 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297238#Comment_297238 Sat, 20 Aug 2022 16:52:51 +0100 owlman Have posed the questions to RIBA? They used to provide local shortlists of architectural practices within their membership, and with specific skills.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297239#Comment_297239 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297239#Comment_297239 Sat, 20 Aug 2022 20:31:26 +0100 richardelliot
I've also searched the Passive House website which is how I found my closest Passive House architect.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297241#Comment_297241 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297241#Comment_297241 Sat, 20 Aug 2022 23:08:24 +0100 djh
If your favourite architect is doing work on a PH for another client and is also interested in designing your house, then why aren't they getting themselves certified? It would seem a no-brainer to me. Unless they have a very, very good reason why not then I'd choose somebody else. Follow your instincts about working relationships.

We didn't use a timber frame company so I can't answer your second question, but I would guess it all comes down to the contract they sign!]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297242#Comment_297242 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297242#Comment_297242 Sun, 21 Aug 2022 06:04:01 +0100 tony
Would you consider doing a scope and letting architects into a competition to do it? Or you could get them to price against that scope.

I would advise a building physics model to inform the design. (Overheating can be a problem but can be designed out or mitigated)

I would not build timber frame preferring masonry for maximum comfort, slow temperature swings, higher capacity to store heat and coolth. Storing these reduces energy use.

How low can you go?]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297244#Comment_297244 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297244#Comment_297244 Sun, 21 Aug 2022 08:24:52 +0100 richardelliot
Posted By: djhYou also need somebody onsite pretty much all the time who knows what is required. Our architect did have a PH certificate but none of our tradespeople did, so I was the person on site.

This is a big fear of mine. I'm based in London and it is almost certain to be able to find a builder who has done it before. I don't have the skills or time to be on site myself either. This is part of the reason why I'm thinking of the timber frame route as (in my head anyway) you get in manufactured in controlled conditions and erected by a team who have done it multiple times before.

Posted By: djhIf your favourite architect is doing work on a PH for another client and is also interested in designing your house, then why aren't they getting themselves certified?

They are planning to get qualified, but it probably wouldn't be achieved in our timelines.

Yes I do Tony!
Posted By: tonyI think that you might mean low energy rather than energy efficient


Posted By: tonyWould you consider doing a scope and letting architects into a competition to do it? Or you could get them to price against that scope.

All the architects near us are pretty busy so no one is going to do any design work / give away their intellectual property for free and we don't have the several thousand they'd each probably want to do some concepts / designs.

Posted By: tonyI would advise a building physics model to inform the design. (Overheating can be a problem but can be designed out or mitigated)

Would this be different from getting the design modelled in PHPP? (We're very conscious of over heating.)]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297248#Comment_297248 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297248#Comment_297248 Sun, 21 Aug 2022 11:11:11 +0100 revor Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297250#Comment_297250 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297250#Comment_297250 Sun, 21 Aug 2022 12:04:23 +0100 WillInAberdeen
That is radically changing the balance on building design, because any building element that doesn't payback its embodied (manufacturing/construction/disposal) carbon within the first decade, will never be able to repay it, and so thereafter will remain a net damage to the environment.

Things which previously were a good idea only 10 years ago (triple glazed windows, concrete in walls and floor slabs, certain thick insulation materials, on-site PV) are now actually becoming damaging overall.

Design methods such as PH/PHPP and BR/SAP do not yet encompass this - they still only look at the impact of the electricity use. Although pressure is growing to change them.

So an architect who just designs to the PH standard using PHPP, might produce a building that is more damaging than an architect who considers the whole-life impact of the building's materials and design choices.

RIBA have a 2030 Climate Challenge which architect practices can sign up to, with a target to reduce embodied carbon by half, as well as improvements in operational energy and water usage. There are guides and calculation tools, also from RICS. You could ask if your candidate architects are signed up to this and have experience of whole-life considerations, if not why not?

https://www.architecture.com/about/policy/climate-action/2030-climate-challenge/faqs

(Edit to add: it should be possible to design a house with low electricity consumption AND low embodied carbon, doesn't have to be either/or, but the best design standards and materials will be different from last time around, I am finding on our 2nd project).]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297253#Comment_297253 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297253#Comment_297253 Sun, 21 Aug 2022 12:56:26 +0100 tony
I would recommend setting your own u-value targets less than 0.1 for main elements 0.7 for fenestration
PH and Building regs set standards but best to aim for much better than either of them]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297260#Comment_297260 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297260#Comment_297260 Sun, 21 Aug 2022 20:55:27 +0100 richardelliot
@WillInAberdeen - I hadn't heard of the RIBA 2030 Climate Challenge but have now watched one of their videos. Yes, definitely plan to be off gas. I'd like to aim for both low energy use and low emobodied carbon. Need to do some more research on why triple glazed windows are no longer considered the best!]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297262#Comment_297262 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297262#Comment_297262 Sun, 21 Aug 2022 22:35:47 +0100 WillInAberdeen
If you were just designing a PH using PHPP then the impact of those extra materials would not automatically be flagged up, so you might want an architect who is able to think this aspect through themselves. This picture has obviously shifted in the last few years, as triple glazing used to be the best option by default, so certain architects might be more up to date with developments.

I got the impression the PH trust are reflecting on how/whether to incorporate this into the PH standard. ."For most new build homes... embodied carbon ...is greater than the operational carbon over its lifetime. This demonstrates how critical it is ...that ‘zero carbon’ homes account for both sources of emissions, rather than only focusing on carbon emissions from [energy] use." (The current PH standard only focusses on impacts from energy use).

They make the point that designing for low heating load, means less materials would be used in the heating system]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297265#Comment_297265 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297265#Comment_297265 Mon, 22 Aug 2022 03:24:43 +0100 Mike1 Posted By: richardelliotWe 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.
This seems to be potentially a good choice to me. You get the local experience to suit your tricky site, plus an architect who is willing to call on specialist PHPP advice rather than bluffing their way through it. However I would want to talk to the engineers too, before going ahead.

Posted By: richardelliotWe're very conscious of over heating.
So are the Passivhaus institute. They have various articles and resources on the topic:
https://passipedia.org/planning/summer_comfort

My own tips would be to
1) model the house using projected climate data for, say, 2050 (which is available), rather than historic data
2) incorporate UFCH pipes at no more than 150mm centres, so that they could be used for light active cooling in the future, should it be necessary
3) mix double & triple glazing if that gives a better result - for example triple on the north, double elsewhere
4) if you can't be on site yourself, consider commissioning a PHPP expert as a part-time Clerk of Works, to monitor the site for you.
5) get the PHPP consultant / Clark of Works put on an induction for the key trades, so that they have at least a basic understanding of PHPP, and their part in achieving it.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297268#Comment_297268 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297268#Comment_297268 Mon, 22 Aug 2022 11:20:43 +0100 djh
The Passivhaus Trust is the UK organization that markets and supports etc PH in the UK. The Passive House Institute is the organization that is responsible for the development of PHPP and the future of the standard.

There is an add-on for PHPP called PHribbon that can calculate the embodied carbon in a passivhaus design, as well as other things. It was developed in the UK but has been adopted by PHI.

Putting in plastic UFH pipes speculatively seems like an excellent way to increase the embodied carbon :)

I believe you need somebody who understands what is required (and has enough authority to be listened to) on site pretty much full time. It's amazing how fast things can go wrong if they're not stopped promptly, and rework is expensive.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297270#Comment_297270 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297270#Comment_297270 Mon, 22 Aug 2022 11:39:18 +0100 djh
"In addition, there are also other factors beyond carbon to consider when installing glazing, which include:

• Winter comfort – only a triple glazed window can achieve this in the UK
• Energy costs – a triple glazed window reduces operational energy use
• Optimisation of total window area, daylighting and frame factor
• The cumulative impact of peak load on the national grid

"Therefore the calculations are not straightforward and should be considered alongside other sustainability
factors. The research concludes by reminding us that there is still uncertainty about the rate at which the grid will
actually be decarbonised and that, rather than looking to downgrade building components, we should be looking
to decarbonise manufacture to reduce embodied carbon, while still ensuring our buildings are comfortable,
affordable to run, and reduce peak load on the grid."]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297272#Comment_297272 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297272#Comment_297272 Mon, 22 Aug 2022 13:13:17 +0100 tony Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297304#Comment_297304 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297304#Comment_297304 Thu, 25 Aug 2022 16:16:19 +0100 Doubting_Thomas
For what it's worth, I think the argument from the PHI about grid decarbonisation is worth considering. They argue quite convincingly that we won't reach a fully-renewables-based grid without demand-side reduction. Much embodied carbon analysis assumes a fully decarbonised grid over a certain timescale, but if that projection is wrong then the numbers start to go adrift.

Which is to say, it's definitely worth factoring in embodied carbon but not at the expense of operational performance. You cannot assume that abundant zero carbon energy will be 'too cheap to meter' any time soon, so whatever the house is built from, it should still be efficient to run.

As WillinAberdeen hinted at in his final line above, there are also performance gains to be gained through the passivhaus process. If you use PHPP to properly optimise the design, it often means that excess glazing, M&E and insulation can all be reduced because the form factor has been refined so that you don't need extra stuff to compensate. There's a good variation on a now famous image showing different building shapes, that shows you the extra thickness of insulation required as the form factor gets worse.

Finally, just to say when I looked at embodied carbon on my build, by far the biggest single item was the PV panels that I included on the roof. There's a whole separate argument about building autarky which I won't get into but it's definitely worth factoring the (considerable) embodied carbon of M&E kit into considerations around energy use and embodied carbon.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297313#Comment_297313 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297313#Comment_297313 Fri, 26 Aug 2022 13:20:28 +0100 modernvictorian Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297314#Comment_297314 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297314#Comment_297314 Fri, 26 Aug 2022 16:11:53 +0100 djh Posted By: modernvictorianwhether the builder will take any notice is a different matter...Absolutely, that's the second requirement. Somebody on site with the authority to get things correct. Or stop work, or check the factory or whatever is needed.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297317#Comment_297317 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297317#Comment_297317 Fri, 26 Aug 2022 18:21:14 +0100 bhommels Posted By: modernvictorianBack to the original question have you considered using your previous architect alongside getting input from a PH qualified consultant? I adopted this halfway house approach and it worked OK, as in the architect was happy to add in the detailing, but whether the builder will take any notice is a different matter...
If it is only about detailing it might just work.
I think it is far better to have the designer and PHPP calculator in one outfit. This ensures the PH aspect is embedded in the design from the get-go and not slapped on afterwards.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297319#Comment_297319 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297319#Comment_297319 Fri, 26 Aug 2022 20:13:33 +0100 djh Posted By: bhommels
Posted By: modernvictorianBack to the original question have you considered using your previous architect alongside getting input from a PH qualified consultant? I adopted this halfway house approach and it worked OK, as in the architect was happy to add in the detailing, but whether the builder will take any notice is a different matter...

If it is only about detailing it might just work.
I think it is far better to have the designer and PHPP calculator in one outfit. This ensures the PH aspect is embedded in the design from the get-go and not slapped on afterwards.I agree, but it's difficult to fudge PH - as long as the result is certified by an independent third party. 'passivhaus-style' can mean anything, but ...]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297324#Comment_297324 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297324#Comment_297324 Sat, 27 Aug 2022 10:01:03 +0100 fostertom
As far as 'slapped on afterwards', you can tell your Architect from the start that he must develop the fundamental design in collaboration with the PH Consultant, including any non-optimal features that he (and/or you) choose to have regardless, which is always possible as long as compensated elsewhere in the design.]]> Choosing an architect for an energy efficient (passive?) new build http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297339#Comment_297339 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17542&Focus=297339#Comment_297339 Sat, 27 Aug 2022 21:54:46 +0100 tony