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Green design standards

a very low energy house at Peterculter

A range of standards

There are now several sets of standards afoot, some greener than others, and it can be quite confusing because they have somewhat different approaches.

Bear in mind that the UK has no legislation about embodied energy and very little about how safe or healthy various building materials are. Added to that is the present government’s recent abandoning of green building initiatives such as the Code for Sustainable Homes and also the Zero energy new housebuild targets. See the BRE  Housing Standards Review web page for, er, clarification

There is an emerging hotchpotch of standards concerning energy use. Herewith an attempt to clarify the subject:

  • There are the current Building Regulations which are mandatory
  • There are various levels of improvement on the Building Regs. which are intended to guide the way to higher standards which will become mandatory in stages over the next decade or so. These are the Code for Sustainable Homes levels 1 to 6.(now scrapped – see below). The government made a clear statement that all new houses should be zero carbon by the year 2016 but it has now backtracked on that. The definition of ‘zero carbon’ has a special and peculiar meaning meaning. See below.
  • There is the continental Passivhaus standard (which is only about energy: not materials) and which is a strong contender to eventually replace all the energy saving aspects of the UK building regs, because it has been up and running well since about 1990.
  • There are the silver and gold standards published by the AECB which are a kind of anglicized version of the Passivhaus standard (with the gold being a bit higher). See below. These may possibly merge into the Passivhaus standard in the future.

It should be noted that none of these standards deal directly with health issues such as Sick Building Syndrome. Many European countries do have such standards and benchmarks which deal with the suitability of materials and health issues.


The Building Regs, part L

These are the mandatory minimum set of standards which any self build project will need to achieve.

Part L1A and part L1B (which are the current mandatory legal standards) have been tightened  as regards thermal insulation and new standards to do with air tightness are being ushered in, though more slowly, and with some resistance from the mainstream building industry.

SAP ( Standard Assessment Procedure) rating is required under the building regulations Part L (England and Wales), Section 6 (Scotland) and Part F (Northern Ireland)). SAP is an energy rating which estimates the annual space and water heating energy use of a house. See the government guidance page on SAP for the latest version.


Code for Sustainable Homes

This has recently been withdrawn (except for legacy cases) and some parts of it have been shifted into the Building Regulations. It was a strange creature anyway with a sort of ‘pick and mix approach’ which was more useful as an awareness stimulator than a fixed standard.


Zero carbon ?

The government originally stated that all new homes shall be ‘zero carbon’ starting from 2016 but has now scrapped that intention. This was based on a general European move towards zero energy building by 2021. See the EPBD. This is an extremely high standard and will require the whole house building industry, at all levels, to reinvent itself, considering that at present (2017) there are very few zero carbon homes in the country and considering also the lamentable skill level and generally low culture of care and thoroughness within the industry. The definition of zero carbon is on the Zero Carbon Hub web site (which is still up though the Zero Carbon Hub has been scrapped)  and was quite controversial because it is aimed at only the building itself and does not generally include the appliances within it.   See the WWF article “Why we’ve resigned from the Zero Carbon Taskforce“.

Larch house entrance

The Larch house at Ebbw Vale is zero carbon

see more on higher standards
Whether the country has the facilities or even the will to retrain the building industry to move from Neanderthal to high tech in a few years is very questionable. To give an example – practically no plumbing courses at any of the colleges of building in the UK ever take their students out to look at a thermal solar collector installation, let alone teach them how to plumb one up. However some of the more forward looking house designers and architects are busy getting to grips with the challenge and producing solutions, e.g. Ruralzed

The government now says it will keep energy standards “under review” (a fairly meaningless statement). The House of Lords Select Committee on National Policy for the Built Environment have recently (2015-2016) done a report called Building Better Places in which they recognise the government’s sad lack of commitment to green building standards with the statement:

2 07.
The Government should reverse its decision to remove the requirement
for new homes to generate no net carbon emissions (known as the
“zero carbon homes” policy) and its decision to remove the Code for
Sustainable Homes. The Government must set out and implement a
viable trajectory towards energy efficiency and carbon reduction in
new homes.


Passivhaus standard

See the main section on the Passivhaus standard

Passivhaus is an extremely high standard of building developed in Germany and Sweden and aimed at producing very low energy usage. There are now many thousand houses, mainly on the continent which have been built to the standard over the last decade or so. It relies on:

  • Very high amounts of insulation.
  • Awesome levels of draught proofing and air tightness.
  • High levels of air quality
  • Heating mainly from passive solar.
  • Heat recovery from whole house mechanical ventilation.

Interestingly the heating load is so low that a central heating system is not required (with the consequent cost savings of maybe £4000 – £5000). A very small amount of heat is injected into the ventilation system electrically (or via a ground source heat pump driven electrically) and for the occasional very low winter temperatures experienced in some parts of Northern Europe a small stove may be included in one room.

This type of low energy building is not intrinsically expensive but takes a degree of skill and care which is very difficult to achieve with the present cultural attitudes towards house building prevalent in the UK.

There is a slightly less strict Passivhaus standard for existing buildings called EnerPHit which acknowledges the difficulties of bringing existing building up to Passivhaus standard

There is also an extended standard called Passivhaus Plus which is about adding green energy generating features such as solar collectors so that the house is a net producer of energy.

The Passivhaus Institute administers the standard and provides training in design.

The standard is only about energy and has nothing to say about other aspects of sustainability such as embodied energy or the health issues of building materials (these are mainly dealt with separately on the continent and tend to come under the heading ‘Building Biology’).

Your architect or designer should be conversant with these standards and be able to advise you on the latest developments.

More about Passivhaus standard

The state of play in Europe regarding low energy building is outlined in an EU article called LOW ENERGY BUILDINGS IN EUROPE: CURRENT STATE OF PLAY, DEFINITIONS AND BEST PRACTICE


The AECB silver and gold standards

AECB standards set up by the Sustainable Building Association under their CarbonLite Programme. These include the Gold standard  the Silver standard and an endorsement of the Passivhaus standard and how it relates to the other two. Excellently put together with lots of example on their web site.

If you are a member of the AECB you can get extensive free information covering the Carbonlite Retrofit Knowledgebase.


The Energy Performance Certificate

The EPC is what you will need to provide if you sell your house or rent it out. It is an assessment of how well your house performs in terms of energy use. There is still considerable disagreement about how well this system of measurement works but it is now in common usage.

From the 1st April 2018, if a landlord lets a privately rented property which is F or G rated then energy efficiency improvements have to be carried out to bring the property up to at least an E rating

1 comment to Green design standards

  • Daryl

    Good Day, can you please cite me the exact UK regulation that says hemp is a authorized material for construction and insulation? I’ve downloaded all the regs and couldn’t find the exact wording. Seems like a moving target from what you’re describing. Thank you,

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