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 energythe total amount of energy it takes to make a material (or a building). See more on 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 HomesCode for Sustainable Homes. A delightful tool for assessing how green a home is. Unfortunately now withdrawn (2015) by this short sighted government. and also the Zero energy new housebuild targets. See the BREBuilding Research Establishment. 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 carbonbit of a slippery fish. It tends to mean that a building uses no carbon (oil, coal, etc) to heat it (meaning in a 'net' way). It usually ignores the carbon which goes into building it (the embodied energy). See the page on 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 reg, because it has been up and running well since about 1990.
- There are the silver and gold standards published by the AECBthe Sustainable Building Association 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.
Currently there is a transition period for part L and there is a good explanation of the latest changes published by the NHBCThe National House-Building Council describes itself as being "the leading warranty and insurance provider and standards setter for UK house-building for new and newly converted homes" as a Technical Extra
Part L (which are the current mandatory legal standards) has been tightened as regards thermal insulation and new standards to do with air tightnessA measure of how leaky a building is to air. In other words, how draughty it might be. There are now standard fan pressure tests to check how air tight a house is and the Building Regulations have minimum standards for all new houses (L1A – Conservation of fuel and power in new dwellings (England)). A much higher degree of air tightness is covered by the Passivhaus standard are being ushered in, though more slowly, and with some resistance from the mainstream building industry. They are likely to be improved considerably over the next decade or so.
A SAPStandard Assessment Procedure - the method used in the building regulations for calculating the energy use of a house. ( Standard Assessment Procedure) rating is required under the building regulationsThese are the mass of regulations that cover safety, health, welfare, convenience, energy efficiency etc. in the way buildings are constructed. Not to be confused with Planning consent (which is more to do with whether you can put up the building in the first place). See more on the regulations (Part L (England and Wales), Section 6 (Scotland) and Part FThe Approved documentsApproved documents (England) are detailed publications which come under the English Building Regulations. They are based on tried and tested methods of building and if you follow them you are assured of complying with the Regs. The equivalents for Scotland are the Technical HandbookUnder the Scottish Building Regulations, the Technical Handbook gives construction principles, which, if you follow them guarantee compliance with the Regulations, for Wales: the Approved documents (Wales), and for N.I. the Technical BookletsUnder the Northern Ireland Building Regulations, the Technical Booklets give construction principles, which, if you follow them guarantee compliance with the Regulations, (England) part F, deals with ventilation (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.
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 EPBDEnergy Performance of Buildings Directive. This is the EU directive that all new buildings shall be "Nearly Zero-Energy Buildings’ from 2021.. This is an extremely high standard and will require the whole house building industry, at all levels, to reinvent itself, considering that at present (2015) 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"The Zero Carbon Hub is a non-profit company limited by guarantee. We are a public/private partnership established to take day-to-day operational responsibility for co-ordinating delivery of low and zero carbon new homes" web site 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“.
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”. 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 standardsIn Scotland, the system administered by a local authority for granting permission for work to be done (Building Warrant) and for a completed building to be occupied (Completion Certificate) see Building Standards with the statement:
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 EnerPHitthe Passivhaus standard as applied to refurbishment of an existing house. It makes allowance for the difficulty of bringing older properties up to a high thermal standard. see Passivhaus refurbishment
Design software is available from the PassivhausSee more on the Passivhaus standard. The PassivHaus Institute has pioneered a standard for low energy buildings. It includes very low energy usage and ways of achieving this. The word is derived from the idea of buildings which are fundamentally low energy and passive solar heated rather than using extra gadgets to heat them. See Passivhaus for the UK branch of the organisation. Trust and BRE and the Passivhaus Trust itself is running courses about how Passivhaus works.
There is a recently produced design manual and Planning Package from the Passivhaus Institute. These design tools are based on robust and practical ways of designing a building rather than the more theoretical calculation methods used by the Code for Sustainable Homes (above).
There is a big question as to whether the Passivhaus approach might be more sensible than the government’s stated intention of going for ‘zero energy’ homes. Whereas zero energy is a higher standard than Passivhaus, it is debatable whether zero energy is practicably achievable within the UK context (except for a small minority of extremely dedicated builders) whereas Passivhaus is now a mainstream and well proven standard across Europe.
Passivhaus standard is only about energy and has nothing to say about other aspects of sustainability such as the health issues of building materials (these are mainly dealt with separately on the continent).
As yet there has only been a very few houses built in the UK which has been certified as reaching the Passivhaus standard.
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.
The Energy Performance Certificate
The EPCenergy performance certificate 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 operation.