With an ever increasing demand on the built environment to meet EU carbon emission targets, why are green facades – given their potential benefits – not implemented more extensively in the UK?

Introduction

Reducing Carbon Emissions

Carbon emission targets Balancing discussion - weigh the implementation of green facades to

other systems for making the built environment more sustainable – green roofs may enhance more than one aspect – but to what degree will they work compared to alternative passive strategies. Environmental implications of green facades in manufacture etc.? NEXT SECTION AFTER POTENTIAL BENEFITS?

Much of the UK is already green space – what of that?

GLOBAL – necessity to act now – issue pressing us all, and yet we must work individually for collective gain – urbanisation - cities – 2% of the earth’s surface, but house 50 % of the world’s population1

“Think Globally, Act Locally” – Rene Dubos2

Energy from fossil fuels consumed in the construction and operation of buildings accounts for approximately half of the UK’s emissions of carbon dioxide. ‘Construction and Sustainable Development’ Plain English, Constructing Excellence, Section 2, Page 5, 01/01/083

The global built environment is responsible for:

Green buildings can deliver:

30-40% of global energy consumption

30-50% reduction in energy use

1 Grant, G., Ecosystem services come to town pp. 52 Grant, G., Ecosystem services come to town, pp. 1113 http://www.ukgbc.org/content/key-statistics-0

30% of greenhouse gas emissions 35% decrease in carbon emissions4

EU plan for preventing dangerous climate change – targets -2012, -2020, -2050: the latter - countries must reduce their greenhouse gas emission by 80-95% of 1990 levels (20% by 2020).5

“Emissions from houses and office buildings can be almost completely cut, by around 90% in 2050. The energy performance of buildings will be improved drastically; 'passive' housing technology will become mainstream for new buildings and old buildings will be retrofitted. Heating, cooling and cooking will be largely powered by electricity and renewable energy, instead of fossil fuels. Investments can be recovered over time through reduced energy bills.”6

CLIMATE CHANGE ACT 2008 – world’s first legally binding targets – GHG emission reductions of at least 80% by 2050, working together with the Committee on Climate Change, independent advisory body for the government

Cleaner Air: “Greater use of clean technologies and electric cars will drastically reduce air pollution in European cities. Fewer people would suffer from asthma and other respiratory diseases; considerably less money would need to be spent on health care and on equipment to control air pollution. By 2050, the EU could save up to €88 billion a year in these areas.”7

Regulated energy use TWh 2010

4 Source: United Nations Environment Programme (UNEP) 2012 http://www.ukgbc.org/content/key-statistics-05 http://ec.europa.eu/clima/policies/brief/eu/index_en.htm6 http://ec.europa.eu/clima/policies/roadmap/perspective/index_en.htm7 http://ec.europa.eu/clima/policies/roadmap/index_en.htm

GHG emissions from regulated energy use in buildings (MtCO2e)

[Capital carbon emissions in 2010 (MtCO2e)] Capital carbon represents about 18% of the total emissions in the built environment. The breakdown of capital carbon emissions is provided in Figure 10 below. These emissions were calculated using the methodology discussed in Section 5.9. Materials account for over 50% of capital carbon emissions.

[ Contribution of material industries to capital carbon in 2010] Almost 60% of materials emissions are from two types of materials: metals and cement concrete and plaster, as shown in Figure 11 below.8

“Buildings that leak heat and waste energy account for 43% of the UK’s total greenhouse gas emissions.” 9

8 Low Carbon Routemap for the UK Built Environment, 5 Mar 2013, the Green Construction Board p 13- 16 9 https://www.gov.uk/government/policies/helping-households-to-cut-their-energy-bills/supporting-pages/green-deal

“Eleven million homes, 60% of all homes with cavity walls, have been fitted with cavity wall insulation. This will reduce the amount the UK spends on heating in 2011 by £1.3 billion.”10

“In the next decade, the UK will complete the installation of proven and cost effective technologies that are worth installing under all future scenarios. All cavity walls and lofts in homes, where practicable, are expected to be insulated by 2020.”11

Green facades offer a number of benefits, but for the UK the only criteria really touched on in the climate change act is that of improving thermal insulation – fails to address UHIE in dense urban cities, dust mitigation etc, all of which are addressed by green roofs.

Potential Benefits of Façade Greening

Environmental/technical information Only beneficial when variables are dealt with appropriately

Evapo-transpirative cooling / Shading The greening of facades employs a naturally intuitive system which

responds directly to diurnal, seasonal or climatic changes, in order to maximise the efficiency of their biological function for photosynthesis, transpiration, evaporation and respiration. During the day, and also seasonally, leaves of vegetation will rise / move towards the light in order to maximise the sunlight incident on the leaf surface area, and close again as sunlight decreases during the day. Consequently, during the hotter seasons, the air between the vegetative layer and the wall is ventilated while in winter the vegetative layer is more compressed and acts as a dense buffer (in the case of evergreen plants) enclosing the stagnant air (performing as an insulative layer) between the vegetation and the wall.12

The vegetative layer is also proven to be more efficient than conventional devices due to the “lower surface plant temperature and higher relative humidity of air shaded by plants” –solar radiation converted into sensible and latent heat through evapo-transpiration. Research studies have attested that solar radiation is more efficient at shading buildings than blinds as they reflect more sunlight.13 Indeed, only 5-30% of incident solar radiation to a wall will reach the wall surface behind the foliage; around 10% is reflected, while the rest is absorbed by leaves. This can considerably reduce not only building surface temperatures and heat flux within buildings but also lower internal room temperatures during summer seasons.

10 The Carbon Plan: Delivering our low carbon future, HM Govt, December 2011, pp. 411 The Carbon Plan: Delivering our low carbon future, HM Govt, December 2011, pp. 412 Green Design: Agnes Novak pp 47-813 Lam, M., et. al. Thermal Shading Effecty of Climbing Plants on Glazed Facades for the World Sustainable Building Conference Tokyo 2005pp.48

Obvious implications to the reliance on plant for cooling a building – energy reductions for air con reduced 23%, annual savings of 8%.14

University of Brighton 2003 Bioshader experiment – Thermal shading effect of climbing plants on glazed facades

two university rooms, of same size, same glazing area, orientation and occupancy; one installed with Bioshader –

few degrees warmer than rest of UK, rarely below -5°, coastal winds,

Virginia Creeper, tall, fast spreading, little maintenance. Results: soplar transmittance 0.43 – 0.14 between one and

five layers of leaves; internal temp reductions of 3.5 – 5.6°C But – shading important in warmer climates-this could be

detrimental to the inerior light qualities of the internal space in more temperate climates –perhaps more beneficial to hot climates, e.g. Consorcio Building, Santiago 1993

Rain water attenuation e.g. Largest Living Wall London Gary Grant Consultancy

UHIE mitigation “It can be said with certainty that, the hotter and drier a climate is,

the more important the effect of green walls and green roofs on mitigating urban temperatures is”. Looking at the effects in comparative climates – Riyadh most effect – hot, arid, decrease 9.1 – 11.3°; Mumbai hot humid less – 8.0 – 6.6°; London Moscow, Montreal – 1.7 - 3.2° from maxima to average day decreases15

“For all [canyon] geometries and cases examined, it can be concluded that the wider a canyon is the smaller the effect of green roofs and green walls on its temperature decreases.” 16 – dominated by street surface area, stronger exposure to solar radiation

Mild climate (Moscow) decrease from “slightly warm” to “comfortable” – not considerable but the study notes that this may be beneficial to the comfort of the comfort of the inhabitants used to the cooler climates. Obviously greater effects recorded in hotter climates – from hot to slightly warm or comfortable, even to slightly cool in early mornings. 17

Thermal comfort Built environment contributes greatly to the heat of our cities – the

hard materials on amplify heat in the

14 Nyuk Hien Wong, Alex Yong Kwang Tan, Yu Chen, Kannagi Sekar, Puay Yok Tan, Derek Chan, Kelly Chiang, Ngian Chung Wong, Thermal evaluation of vertical greenery systems for building walls, Building and Environment, Volume 45, Issue 3, March 2010, Pages 66315 E. Alexandri, P. Jones / Building and Environment 43 Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates (2008) 48616 E. Alexandri, P. Jones / Building and Environment 43 Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates (2008) 48917 E. Alexandri, P. Jones / Building and Environment 43 Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates (2008) 490-91

e.g. Sheffield Study corroboration

Biodiversity Planting green roofs book- pp 198 biodiversity Increased urbanisation puts the UK’s biodiversity at risk. Habitats

in decline, butterfly populations dropped 55% 30 years18

a not unimportant consideration given the frequently reported plight of the bumble bee and the resulting impact on pollination.19

M&S Sheffield Lewis and Hickey "An admirable project from such a huge and respected client, the building has been used to test a number of building initiatives to further develop sustainable store design. The architects have used reclaimed brickwork, a living wall and pollarded trees to enclose a low energy, naturally lit retail space. Loved by staff and shoppers alike, the building makes a positive contribution to the life of the street.”20

http://www.lewishickey.com/who-we-are/awards-article/riba- 2012-white-rose-award

Dust Mitigation NASA pp. 197 planting green roofs book. Lead and cadmium highest on dead leaves and wood, falls to

ground, removed and disposed from the site (dust trapping proportional to area of leaf surface to wall area) Koehler notes 6g/m2 by Hedera Helix

(http://cleanairinlondon.org/legal/government-admits-widespread-breaches-of-air-pollution-laws/)

“Clean Air in London” Jun 28 2012 – breached EU laws on the levels of NO2 – levels set in 1999, some due to be reached by 1 January 2010, but some not until 1 January 2015 – appeal for all to be until then even though unlikely to meet even those targets – only 3 of 43 UK zones compliant by 2010.

“Air pollution is the biggest public health risk after smoking” causing asthma, cardiovascular diseases >65 yrs,

“London, for example has the highest annual mean concentrations of NO2, a toxic gas, of any capital city in Europe in 2010 with levels comp[arable to Beijing before it took action for the 2008 Olympics.”21

Boris Johnson was accused in 2012 for placing pollution suppressants (calcium magnesium acetate) in front of the air quality monitors, like “like putting an oxygen mask on the canary in the mines".22 Gardiner continued that, “Asthma and other

18 Defra (2008) Populations of Butterflies in England; England Biodiversity Strategy Indicators (Part H1(b)) /m&S study19 http://sustainmagazine.com/think-greenfrastructure/ 19/10/1320 http://www.architecture.com/RegionsAndInternational/UKNationsAndRegions/England/RIBAYorkshire/Awards/SheffieldDesignAwards/SheffieldDesignAwards2012/2012shortlist/MarksandSpencer.aspx#.UmKNH_m-2uI21 http://cleanairinlondon.org/wp-content/uploads/CAL-187-EC-rejects-time-extensions-in-12-UK-zones-2806122.pdf

illnesses caused by air pollution are estimated by the government to cost the UK more than £8.5bn each year”

The herbaceous plants and other vegetation of which the walls and screens are comprised absorb particulate matter (PM10s) and release oxygen through photosynthesis. The importance of this in congested urban areas cannot be overstated.23

EDGWARE TUBE STATION MARLYBONE / 2011 28 novDesigned to counter sir pollution in central London, funded by TFL – GOVT INCENTIVE!! 200m2 / leadership of client to informing the urban environment directly

The delivery of Green Infrastructure (GI) including trials of green walls and associated research supports the growing evidence that the delivery of GI can improve urban air quality and deliver many other environmental benefits.

“which is also enabling tree planting projects such as the 50 planted towers on Lower Thames Street and 200 lime trees along the A40 — seriously reduce the level of particulate matter in London’s air. Earlier this year the government temporarily dodged £300m in fines for breaching EU limits on air pollution but the situation has not really improved. The environmental audit committee (EAC) of MPs was recently accused of “actively trying to dilute safety standards“, in order to avoid fines from the EU for breaches of the rules”24

“unprecedented programme of green infrastructure” - Boris Johnson 25

Biotecture used in RIBA Florence Terrace at their headquarters in Portland Place, London.

GRODAN SUBSTRATE! Ecosheet waterproof layer uk recycled material, installed by Biotecture Ltd. 26 “lowest water use of any known comparable living wall system. Average water use in a typical UK installation is 1 litre per m2 per day”

Tested in various climates which support plants from -20 to 60 degrees, used in N America and being trialled atm in the middle east.

GRODAN Danish firm who make the “sustainable” substrate of stone wool; manufacturing process:

22 Barry Gardiner, MP quoted on http://www.theguardian.com/environment/2012/apr/24/boris-johnson-london-air-pollution23 http://sustainmagazine.com/think-greenfrastructure/ 19/10/1324 http://londonist.com/2011/11/green-wall-to-tackle-air-pollution-at-edgware-road-station.php25 http://www.london.gov.uk/media/mayor-press-releases/2011/11/stunning-green-wall-unveiled-at-edgware-road-tube-station-to

26 http://www.biotecture.uk.com/portfolio/edgware-road-tube-station-marylebone/

Stone wool Stone wool is a natural product. It is made from Basalt, solidified lava spewed from the innermost depths of the earth. In the mid-nineteenth century, American geologists on Hawaii discovered a “woolly” material consisting of stone threads, which the local inhabitants were using to insulate their huts. This was a volcanic material, the product of red-hot steam being forced through liquid lava under high-pressure. 

To produce stone wool commercially, Grodan/Rockwool duplicated this natural process as closely as possible. Today, extracted basalt is re-liquefied in furnaces at a temperature of 1,500 °C. The liquid Basalt is then spun into threads in spinning chambers, and then congealed in a hardening kiln using hot air (230 °C) and compressed into wool packets, which are then cut into slabs, blocks or plugs and packaged in film. With factory processing, one cubic metre of basalt can produce approximately fifty cubic metres of stone wool.

Efficient use of water and nutrients keeps yield per square metre high, and energy consumption per unit of product low. Additionally, the product is lightweight, making it easy to use. And last but not least, stone wool can be easily re-used. 27

Certificate of European Ecolabel

Psychological Part of our natural being, comfort, survival instinct. “importance of greenery and green space in enhancing a sense of

well-being.” / “Findings show that urban green space can deliver significant benefits for mental wellbeing,” uni of Exeter European centre of environment and human health – psychological science 28

Ulrich study – hospital patients’ recovery time noticeably fast when kept within a roof overlooking trees compared with patients recovering from the same surgical procedure who looked out to a brick wall.

Acoustics27 http://www.grodan.com/about+grodan/stone+wool+substrate28 http://sustainmagazine.com/think-greenfrastructure/ 19/10/13

Alternatives “but smaller spaces demand a decision on which aspect of

sustainability will be the key driver.”29 – consideration for the other strategies – PV panels, water collection - green walls obviously not always the go-to solution, and it must be strongly considered what the main ambitions of the project are.

Social

History - change in attitude – traditional ivy covered buildings, aesthetic, rural

> SHIFT IN ATTITUDE > Hundertwasser awareness of the global warming and the potential to change through our built environment, modern systems - welcomed? Not embraced? > Modern systems - two motivations – sustainability or aesthetic.

Conservative preservation of dense inner cities – where these strategies are required most.

Historical urban development leaves little green space – new ways of greening are proposed30

New York Economic Development Corporation – minimise the appearance as a “concrete box”31

Public bodies need to advocate the implementation of green infrastructure – not only the regulatory bodies of the profession, but also NHS, local authorities – start with the public urban environment, ideas with filtrate to the general public to become more accepted forms of the urban environment.

RETROFIT, appendage to design? Yes, when working with our existing building stock but it needs to be more integral thought to new design, not merely an ‘add-on’.32 Not a “given a veneer of green respectability”33

Conservation: “Heritage considerations must always be taken into account, and planting must avoid concealing any part of façades with historical or aesthetic importance.” 34

“cultural inhibitions” need to be addressed “mixing strong-growing vegetation and buildings need addressing too”35

“perhaps the equable climate of the British isles and the preponderance of private gardens have created an intellectual cocoon shielding us from some of the more urgent environmental problems facing most other people in the world.” Pp. 17 grant, green roofs and facades

29 http://sustainmagazine.com/a-growing-phenomenon/ 19/10/1330 http://sustainmagazine.com/think-greenfrastructure/ 19/10/1331 http://sustainmagazine.com/a-growing-phenomenon/ 19/10/1332 http://sustainmagazine.com/think-greenfrastructure/ 19/10/1333 http://sustainmagazine.com/think-greenfrastructure/ 19/10/1334 https://www.london.gov.uk/sites/default/files/2012-10-15%20Delivering%20Vertical%20Greening.pdf 12 Oct 201235 Dunnett, N., Kingsbury, N., Planting Green Roofs and Living Walls, Timber Press, London 2008 pp. 192

Climate

Sheffield Research into Living walls , Feb 2013 Running for one year. Potential of exploiting the surface of facades

– greater area than green roofs – even if the latter is more efficient – with more green facades, and in conjunction with green roofs, the effects of climate change may be mitigated.

Three types of LWS tested, two types of climbers installed on SW wall, data will be recorded to ascertain the benefits for building energy performance, and indoor thermal comfort.

Uni of Sheffield together with Scotscape Ltd. And EPSRC Initial costs major disadvantage – this study aims to provide

quantifiable data on the performance of green facades / living walls in the UK (literature is limited to warmer climates)

“Studies have shown that covering the surfaces of buildings in urban environments with green plants results in an improvement in air quality, aesthetics and wellbeing.” explained Dr Hasim Altan from the University of Sheffield’s School of Architecture. “However, most of these studies have taken place in climates significantly warmer than the UK. Our study will find out how living walls fare in the UK’s weather and how they can be of most benefit in this country.”36

Irrigation systems – concerns of MAINTENANCE AND ENVIRONMENTAL COSTS.

JURI YOSHIMI PhD study

Legislative/Economic

Maintenance costs Government policies and incentives to counteract the above?

Conclusion

ABBREVIATIONS

GHG – Greenhouse Gas Emissions

UHIE – Urban heat Island Effect

36 http://www.sheffield.ac.uk/news/nr/living-walls-1.253985