This is something that we should talk about

A good review of the review here http://www.sustainablehomes.co.uk/the-bonfield-review-better-late-than-never/?utm_campaign=SHIFT+Awards+2016&utm_source=hs_email&utm_medium=email&utm_content=41667821&_hsenc=p2ANqtz-82Alw0vgLi9Jvnu9oT8xUVqbnXIkqGCmIkRJhEFHp2vy_afgp4CCGUKVwg0P-Yy9ZzfIZodYUYARYozvPJPhjZ-Rqi7w&_hsmi=41667821

The review is making good points and I hope that result in changes like enforcement, monitoring and better buildings.

Having skimmed through it several things worry me

A) a new standard -- the standard

B) No SMART targets, promote, encourage etc with no numbers or real targets.

C) Social housing gets a mention at the bottom of the paper

More to come if I can muster the enthusiasm to plough through it -- I hope it works but can't see it curing the mustard

Actually the 'talking shop' was in reality a number of workstreams that fed up a lot of good ideas and recommendations and suggestions and also quite a lot of detail - however brevity and politics got in the way of a much quicker release and a more detailed set of recommendations.

The process is continuing and should drive changes, so overall positive I feel.

The importance of Survey, Design, Specification and Installation and also Consumer Confidence, Redress and Guidance all got covered.

I'd also have liked to have seen more to drive up the energy efficiency of homes for the general populace and suggestions for better policies and nudges to encourage appropriate, quality improvements to happen.

as big as 'of Mexico'.....

I agree with with Ed Davies, if there was just no gaps in the insulation and air tightness that lasted then I would not be too unhappy with the Part L standards. Therefore a requirement for the air tightness testing to be repeated at the end of year 5 and 10 on 100% of the homes, along with surveys with a thermal image and the builder having to fix the issues found may be all that is needed.

As soon as the quality of insulation can be trusted so that running costs are what the EPC says they should be, then the EPC rating may drive improvements to insulation standards.

My memory is that current regs are nowhere near where we need to be for one-planet, but maybe my memory is faulty.

The 'regs', ie Part L Building Regs, and partly Part F, are not enforced properly, regardless of what they purport to regulate.
Building Control officers (both LA and Approved Inspectors) are desperate for business, and so not going to bite the hands that feed them, are they...... So as long as they have insurance backing, the temptation to let things 'slip' is too great.
Coupled with a lack of training / CPD / call it what you will, in the building construction industry, this means mistakes & short cuts will still occur....

There was a comparison done against 2010 regs that may be helpful:

http://www.bere.co.uk/sites/default/files/research/16PHT_Nick%20Newman%20submission.pdf

It assumes of course that buildings are actually built to the standards.

Posted By: DarylPThe biggest 'movers' are now air-tightness, which is the one thing that the developers/contractors can influence/improve,

Airtightness is really a design-time thing as well. If a building isn't designed with an airtightness layer, it can be very difficult (impossible) to include one later. For sure developers/contractors often make things worse and a design is no good without attention at the construction stage as well. But much the same goes for insulation and to some extent for thermal bridging.

Daryl, I think we're in violent agreement but I was hoping you could run some numbers to support it. That bere study is interesting but a) 2010 regs are worse than 2013 (at least that house wouldn't meet current (2013) Scottish area-weighted U-value maximums) and b) it assumes it's very leaky.

Their hypothetical part-L house has 3.85 times the gas usage (and 1.2 times the electricity usage) of the hypothetical Manchester Passivhaus. The question is, if the part-L house had the Passivhaus's airtightness how much lower would those multipliers be?

These numbers aren't great:

http://www.gov.scot/resource/buildingstandards/2013Domestic/chunks/ch07s03.html#d5e16076

but if they were enforced and seen as the least you can get away with without actually being thrown in jail rather than as goals to be aspired to I think they'd by OK.

What I worry is that calls for tighter regulations would just result in these U-values being reduced further whereas it'd be much more productive to concentrate on enforcement and air tightness.

The current political imperative is to build as many homes as fast as possible. Most trades on most sites are working on a priced basis so houses are thrown up as fast as practically possible by trades with little interest/training in obtaining optimum results.
In the vast majority of cases , the occupiers of new homes will find energy efficiency is greatly improved on older stock they have lived in and be happy.
The increased cost and time needed to build homes to a more sustainable homes was effectively the reason the goverment backed off on the introduction of the sustainability codes.
There is no appetite to enforce current standards as in the drive to conjure up co2 savings all builds will be asumed to have reached the levels required , the last thing needed is real evidence that such homes do not perform as expected.

The Bonfield Revew specifically didn't cover New Build.

Zero carbon Hub's design vs As-built work did look at quality and gave a number of recommendations, but they closed when Government decided to ditch Zero Carbon standards for 2016.

The Zero Carbon standards were ditched on the basis of an impact statement that was amended/revised and costs reduced after the decision was made. The government policy at the time was that no new standards could be introduced without savings to builders elsewhere to balance any increased costs - savings to the occupiers of buildings and to the UK weren't considered.

Retrofit Standards for England didn't change in 2013.

Quality of work is desperately in need of improvement for existing and for new build.

LABC don't have the resources to enforce quality due to funding cutbacks - the money that Building Control and Planning Departments take in is diverted to under-resourced adult social care etc by the Local Authorities, because of government funding cut-backs and it doesn't stay within those departments.

The reality is that better performing, better designed and detailed homes are possible at minimal additional cost, but with far better outcomes for occupants and the environment, but it's only likely to happen if building standards improve to force the issue.

Transitional arrangements urgently need looking at to avoid poorer performing housing continuing to be built using them to bank regulations compliance.

Posted By: ringiYet in the UK, no one will commit buying identical prefabs at a constant rate for 10 year…..

https://www.youtube.com/watch?v=2_2lGkEU4Xs

Couldn't resist it..........sorry!

DarylP and I have been having a whispered conversation about the relative effects of airtightness on otherwise to-building-regs houses.

The first point which emerged, which I knew but hadn't fully internalized, is that a house that meets the building regs U-values for each of the elements (floor, roof, walls, windows, etc) will not meet the overall requirements. E.g., if you have the worst allowable wall insulation then you have to have a better roof or whatever to compensate. Therefore just looking at the maximum allowable U-values can be misleading.

Secondly, as I thought, airtightness is the big hole. If you take a to-building-regs house with 10 m/h [¹] air-permeability and improved it to Passiv levels (0.6 air changes/h, strictly, but 0.6 m/h I think for these calculations; it doesn't make much difference) you get a nearly 20% saving in heat loss which, I think, supports the idea that the next stage of improvements in building regs (assuming the government doesn't scrap the whole idea of regulating at all) should concentrate on airtightness rather than U-values.

Apart from anything else, airtightness is something that can be one-off relatively independently tested whereas checking insulation installation requires continuous on-site monitoring.

[¹] I.e., m³/m²·h if the cancellation bothers you. It's just the average speed of the airflow through the fabric so using speed units seems quite sensible to me.

I think the 20% is a bit optimistic.

Currently, houses aren't built with the aim of being exactly 10 m³/m²/h, they're just built at random except that the 'tight' end of the distribution is cut off by making extra holes in the fabric if it is too airtight and would require mechanical ventilation. So I think you're assuming too much benefit from tighter building. That's by contrast with insulation levels that are specifically targetted at the worst case.

Also, I think we're some distance away from being able to build every new house in the country to passivhaus level of airtightness. I know there are some districts in Germany and Ireland that do require it, but it's not as easy as it seems at scale I suggest.

Finally, an airtight house needs a mechanical ventilation system so that needs costing in to the comparison on both monetary and carbon basis. Did your 20% allow for that? What ventilation system was assumed (PIV, MEV, MVHR)?