EnerPHit changes to 20kWhr/m2yr in Southern England

Whilst this helps with achieving low energy retrofits and buildings, coupled with another change this has serious implications for future refurbishment projects.  The PHI has reclassified the targets for EnerPHit dependent on the climate  the project is in, reducing from 25kWh/m2a to 20kWh/m2a in Warm Temperate zones.

The zones affected include London, Efford and Exeter, or zones 1  3 and 5 within the PHPP model.

Following the releases of the new PHPP 9, we’ve completed a number of PHPP models for early stage projects looking to retrofit to EnerPHit or even Passivhaus standards.  One interesting discovery that has implications is the fact that some areas in the UK are now classified as Warm Temperate rather than Cool Temperate.

Interestingly, the climate also shifts the other way in the North, with some areas of Northern England and Scotland changing from Cool Temperate to Cold, dependent on the altitude of the project site.  Again a small change, but the EnerPHit target changes to 30kWh/m2a, which could come in handy if you’re retrofitting in Wanlockhead, Scotland’s highest village at 402m above sea level.

The altitude is significant in each case, due to the PHPP accounting for higher sites by reducing the temperature by a constant 0.6K per 100m difference to the climate station.  Zones where the data is collected with a low station may be overly affected by this assumption, or this may be an accurate representation of the changing of altitude (I’m not a Climate Scientist…).  Further information is on the Passipedia website here.

This means that all EnerPHits in London will need to meet the 20kWh/m2a target, as will many further south in zones 3-6.  It also raises the question about EnerPHits following the component route, and in particular with windows, as the requirements for U Values reduces in Warm Temperate climates from an overall 0.85W/m2K to 1.05W/m2K.

This may result in a higher take-up of the component route in southern England. Further information on EnerPHit component route and its criteria can be found here.

Below we have summarised the climate zones in a table, showing which areas may be affected.

Patrick Osborne 18/01/2016

Climate Zone of station Warm Temperate20 Cool Temperate25 Cold30 Counties in Climate Zone Approximate Highest point in area
Zone 1 – London Warm Temperate 0-145m 146m-711m 712m+ Inner London 134m
Zone 2 – Thames Valley Cool Temperate – 0-517m 518m+ Surrey, Berkshire, Oxfordshire, Buckinghamshire, Bedfordshire, Hertfordshire 297m
Zone 3 – London Gatwick Cool Temperate – 0m-578m 579m+ Kent, East Sussex, West Sussex 280m
Zone 4 – Efford Warm Temperate 0-127m 128m-657m 658m+ Hampshire, Dorset 286m
Zone 5 – Exeter Warm Temperate 0-125m 126m-656m 657m+ Devon, Cornwall 621m
Zone 6 – Lyneham Cool Temperate – 0m-540m 541m+ Somerset, Wiltshire, Avon, Gloucestershire, Gwent, West, Mid, and South Glamorgan 519m
Zone 7 – Sutton Bonnington Cool Temperate – 0-423m 424m+ Hereford, Worcestershire, Warwickshire, Northamptonshire, Leicestershire, Nottinghamshire, Derbyshire, Staffordshire 703m
Zone 8 – Fairfield Cool Temperate – 0-526m 527m+ Clwyd, Cheshire, Merseyside, Greater Manchester, Lancashire 628m
Zone 9 – Carlisle Cool Temperate – 0-331m 332m+ Cumbria, Dumfries and Galloway 978m
Zone 10 – Eskalemuir Cold – 0-188m 189m+ Scottish Borders, Northumberland, Tyne and Wear 840m
Zone 11 – Leeming Cool Temperate – 0-318m 319m+ North Yorkshire, Durham, Cleveland 788m
Zone 12 – Waddington Cool Temperate – 0-443m 444m+ Lincolnshire, Humberside, West and South Yorkshire, Nottinghamshire 582m
Zone 13 – Hemsby Cool Temperate – 0m-526m 527m+ Cambridgeshire, Norfolk, Suffolk, Essex 147m
Zone 14 – Sennybridge Cool Temperate – 0-457m 458m+ Dyfed; Powys, Gwynedd 1085m
Zone 15 – Glasgow Airport Cool Temperate – 0-264m 265m+ South Ayrshire, East and North Ayrshire, South Lanarkshire, Inverclyde, East Renfrewshire and Renfrewshire, Glasgow, North Lanarkshire, Stirling, Argyll and Bute 1174m
Zone 16 – Dundee Cool Temperate – 0-238m 239m+ Tayside, Clackmannanshire, Fife, Angus, Dundee, West Lothian 1068m
Zone 17 – Aberdeen Cool Temperate – 0-178m 179m+ Moray, Aberdeenshire, Aberdeen 1309m
Zone 18 – Aviemore Cold – 0-176 177m+ Skye and Lochalsh, Lochaber, Caithness, Sutherland, Ross and Cromarty, Badenoch and Strathspey, Nairn, Inverness 1344m
Zone 19 – Stornoway Cool Temperate – 0-163m 164m+ Western Isles 799m
Zone 20 – Kirkwall Airport Cool Temperate – 0-59m 60m+ Orkney 481m
Zone 21 – Lerwick Cold – 0-7m 8m+ Shetland 450m
Zone 22 – Belfast-Aldergrove Cool Temperate – 0-362m 363m+ Fermanagh, Tyrone, Londonderry, Antrim, Armagh, Down, 850m

Values taken from PHPP v9.3.  Where altitudes of the climate zone are not met, i.e. the highest point in the area is lower than that of the switch to a different climate zone, the figures are greyed out.  Please note this includes a minor correction to PHPP v9.3 please speak to your certifier for details, and if you get different results than above.

Updated 03/02/2016