ideahaus - a comfortable home for the uk's future climate

IDEAhaus

A Comfortable Home for the UK’s Future Climate Ian McHughGreen Triangle Studio

Presentation to:

ManchesterSchool of Architecture

Mar 2015

Enquiries: green.triangle@btinternet.com

Why do we need more housing?

Housing Supply MegagraphBy Alastair Parvin of Architecture00:/ and Toby Lloyd of Shelter

The UK housing supply shortfall is roughly the equivalent of *not* building Cambridge - three times - every year

Problems?

We think there are two big problems UK housing is not facing up to:

1. UK housing is not being designed to deal with Climate Change

2. Industrialisation has not been exploited successfully in UK housing construction

• Liverpool based Case Study• Funded by Technology Strategy Board

•https://connect.innovateuk.org/home•Free registration

• Design For Future Climate programme • Case studies at

•https://connect.innovateuk.org/web/design-for-future-climate/projects-outputs

IDEAhaus

• Climate Change

• IDEAhaus Concept

• Design

What is Climate Change Mitigation?

Climate Change Mitigation is about saving the planet from us.

What is Climate Change Adaptation?

Climate Change Adaptation is about saving us from the planet.

Cave or Pavilion?

Why do we need to adapt?

“The rate of increase for this past decade is higher than any decade since the start of the atmospheric CO2 instrument record in March 1958.”

Calculations are based on NOAA-ESRL data (Mauna Loa Observatory) dated January 9, 2014

25% increase in 50 years!

Why do we need to adapt?

“A new NASA study underscores the fact that greenhouse gases generated by human activity — not changes in solar activity — are the primary force driving global warming.

The study offers an updated calculation of the Earth's energy imbalance, the difference between the amount of solar energy absorbed by Earth's surface and the amount returned to space as heat. The researchers' calculations show that, despite unusually low solar activity between 2005 and 2010, the planet continued to absorb more energy than it returned to space.”

James Hansen, director of NASA's Goddard Institute for Space Studies (GISS) Jan. 30, 2012

Why do we need to adapt?

Temperature data from four international science institutions. All show rapid warming in the past few decades and that the last decade has been the warmest on record.

Consensus: 97% of climate

scientists agree

Future Climate - Global

Temp Rise °C

Global Average Temperature Changes

Climate Change is Unavoidable

Source: Intergovernmental Panel on Climate Change (IPCC)

Emission scenarios:

High

Medium

Low

A rise of 4°C would threaten London, New York & Tokyo from sea level rise!

We are here

Building designers assume temperatures will stay the same

Why do we need to adapt?

The Scientist’s view:

‘I’d rather slam my **** in a door than debate climate change’British scientist, Guardian columnist and Author of ‘Bad Science’, Ben Goldacre

Do we need to adapt?

Do we need to adapt?

The Industry View:

“The overheating is negligible and the air-con can deal with it”Contractor (who will remain anonymous!) 2012

Why do we need to adapt?

Future Climate - UK

Headline Impacts:The most recent UKCP09 government projections show:

• Hotter drier summers

• Wetter warmer winters

• Extreme events more likely

• Sea level rise

Flooding

• Flood return periods are shown falling drastically

– eg. a current 100 year flood would be likely on average every 45 years by 2080

• There is no projection to show a future 100 year event

UK Met Office graphs showing changes in return period for winter rainfall events in Liverpool 2012-2080

Floods will be much more frequent

Temperature – NW England

‘ProCliP’ diagrams show the range of probable temperatures with different scenarios

This helps to inform risk based decisions about design and investment now

Which one is relevant to your building?

All future scenarios show a steep rise in temperature

Risk?

Psychrometric Analysis

Liverpool Psychrometric charts. Baseline climatic data from University of Exeter, Prometheus project 2010 Design Summer Year 2080 Hi-Em 90th Percentile

Prometheus creates simulated weather files for sample years from the climate projections so we can look at models for temperature and humidity and appropriate environmental design strategies:• Current DSY – little need for environmental control other than solar• 2030 Hi-Em 90th% - need for co-ordinated cooling strategy – thermal mass• 2050 Hi-Em 90th% - increased humidity – more ventilation & high thermal mass• 2080 Hi-Em 90th% - increased temp & humidity – passive difficult, consider ground cooling too?

- average increase in summer temperature = 9°C!

Something like Rome!

Psychrometric Analysis

Liverpool Psychrometric charts. Baseline climatic data from University of Exeter, Prometheus project 2010 Design Summer Year 2080 Hi-Em 90th Percentile

In plain English this looks something like this - Liverpool climate in 2080 looks more like Rome now!

• Current DSY – little need for environmental control other than solar• 2030 Hi-Em 90th% - need for co-ordinated cooling strategy – thermal mass• 2050 Hi-Em 90th% - increased humidity – more ventilation & high thermal mass• 2080 Hi-Em 90th% - increased temp & humidity – passive difficult, consider ground cooling too?

- average increase in summer temperature = 9°C!

Climate Change Risk Assessment (CCRA)

Weather not Climate!For design we are interested in:

• Temperature

• Rain

• Wind

Risk = Likelihood + ImpactInsurers and lenders will always protect their interests

Are we Designing for the ride?

Or Designing for the crash?

Or Don’t know?

What is your Asset Protection Policy on Climate Change?

Have you assessed the risks?

Risks We Identified• Highest number of risks for flooding

• Greatest severity of risk for overheating

• Wind projections within safety margins (but projected data for extreme gusts was lacking)

Passive Cooling Principles

Preventing heat gains

• solar shading

• insulation

• internal gains

Modulation of heat gains

• thermal mass

• air movement

Heat dissipation

• night ventilation

• evaporative cooling

• ground cooling

Baseline House - Thermal modelling

Overheating

Overheating is already happening and will become unbearable!

• Benchmark guidance (CIBSE) is not to exceed 28degC for more than 1% of habitable hours

• Analysis of high spec ‘baseline’ house showed:

Now (2010 DSY) • 6.6% annual• 28.4% Jul/Aug• Hottest day 25-36degC

Future (2080 HiEm90%)• 50.5% annual• 74.6% Jul/Aug• Hottest day 30-40degC

Baseline scheme

• Standard Timber frame housetype

• Aspirational specificationU-values 0.11W/m2KAir tightness 3m3/h/m2

Baseline House - Energy modelling

Energy demand• Space heating

• Equipment

• Hot water

• Lighting

• Space cooling?

Our analysis showed current new houses ‘need’ space cooling (air-con) to be comfortable in the summer

In 2080 there is hardly any heating needed and summer energy use is higher than winter due to cooling demand

2010

2080HiEms90th%

Without air-con With air-con (over 25degC)

Energy breakdown profile (Sefaira) on baseline timber frame housetype for 2010 & 2080 Hi-em 90th%tile

Baseline House - Energy modelling

Energy demand• With air-con• Without air-con

Analysis shows energy demand without air-con falling by over 20% but with air-con the saving is only about 10%

Heating v Cooling demand• Heating demand falls• Cooling demand rises• Energy ‘crossover’ by 2038?

If cooling is by air-con, the carbon and cost crossovers would be much sooner because grid electricity is much more carbon intensive and expensive than standard gas heating.

Annual Energy Consumption

0

2,000

4,000

6,000

8,000

10,000

12,000

2013 2030 2050 2080

Year

kWh

Baseline Air Conditioned

Energy use (IES) on baseline timber frame housetype for 2010 & 2030, 2050, 2080 Hi-em 90th%tile

IDEAhaus Concept

We wanted a future housing product which could be

• mass produced

• flexible in design

• passive design

• climate resilient

It should be:

• Industrialised

• Delightful

• Efficient

• Adaptable

…an IDEAhaus!

Industrialised

The benefits of Industrialised manufacturing are well known:

Standardisation• Mass produced core components

Manufacturing Quality• Enhanced under factory

conditions

Predictable Cost & Delivery• Repetitive components &

assembly

Economies of Scale• Bulk purchasing and ‘stock’ items

Delightful

Houses must be loved to live long, so they are designed to be:

Spacious• Generous layouts, room

heights & central lightwell

Individualised• options for rooms, windows,

cladding & finishes

Comfortable• Good environmental control

& performance

Quality• High quality products

specification

Elevational options – brick, timber, render/panel

Efficient

Efficiency is built-in through:

Passive Design• Highly insulated,

thermal mass, natural vent & shading

Renewable energy• Designed for integration

Low impact materials• Sustainable sourcing, waste

engineered out

Fast construction• Predictable lead in &

construction to watertight shell

Adaptable

Adaptability is embedded in the designs by providing:

Flexible Layout• Lifetime Homes accessibility

standard

• Variable dwelling size

Climate Resilience• Flood & overheating resilient

construction

Additive Features• Exo-structure options &

vertical extension

Upgradable Performance• Replaceable cladding, solar

panels & services 4B6P house

Mass Customisation

Enhanced use of computerisation in design and manufacturing make it easier to customise and provide variations on ‘standard’ components.

The IDEAhaus concept is therefore based around a

Kit of Parts

• Core Construction

– A small number of large repeatable elements

• Additive Components

– A large number of small changeable elements

• Adaptable Services

– Integrated services distribution and ability to plug-in new or upgraded features easily

Core Construction 1

FoundationsFast and suitable for any site (almost)

• Helical steel screw piles

Ground FloorThermal mass and built in flood resistance

• Precast concrete units with upstandedgebeams on insulated bearing blocks

• Bonded damp membrane & closed cell insulation

• Standard sized units

Core Construction 2

Wall Cassettes• Pre-insulated timber frame

with 120mm precast Hemcrete & 200mm hemp fibre

– Thermal mass

– Phase change (?)

– Breathable

– Humidity control

Upper Floor Cassettes• Open panel timber

• Hollow clay block infill Ibstock ‘Coolvault’

– Thermal mass

– Self finished

Core Construction 3

Central Volumetric UnitSuitable for all house types and could be a fully finished ‘stock’ item

• Standardised bathrooms, stairs & heating system

South Facing RoofExploited for solar aspect and storage/services

• 30°pitch volumetric

– trussed rafters on framed purlins with boarded finishes

North facing roofExploited for amenity/bio-diversity

• Pre-insulated closed panel cassettes

Additive Components 1

External CladdingStructural grid allows variety of materials and window proportions

• Typical finishes shown

• Others equally viable

Green Roof/ GardenRoofs made to work hard!

• Bio-diversity

• Rainwater attenuation

• Cooling micro-climate

Fit Out• Typical UK social housing

layouts shown

• Allows for bespoke rooms & finishes

Elevational options – brick, timber, render/panel?

Roof options – bio-diversity and/or amenity space?

Additive Components 2

Exo-structureAllows an outer layer of features to be added or changed

• Grid of thermally broken fixing points in façade

• A range of add-on components 1.2m deep eg.

– Porches

– Shading

– Balconies

– Trelliswork

Extra FloorsStructure allows future adaptation

• Add staircase

• Re-use roof cassettes

Adaptable Services 1

PV-ThermalMaximise potential of roofspace

• Combined solar hot water & PV cells

• 40% greater energy yield?

Underfloor heating & cooling Maximise design flexibility and performance

• Radiant for comfort

• Works with thermal mass

• Efficient for heat exchangers

• Disperses heat for summer cooling

• Frees up floor plan & wall space

Adaptable Services 2

Natural VentilationSimple and intuitive for responsive user control, low installation & maintenance cost and good indoor air quality

• Avoid whole house MVHR!

• Window patterns to enhance single sided ventilation & allow night vent heat purge

• Fans with HR for kitchens & bathrooms

• Central rooflight & stairwell for cross vent options

IDEAhaus - Thermal Modelling

Overheating Comparison

Analysis (IES) shows IDEAhaus makes a big improvement to summer comfort compared to the Baseline House (high spec timber frame).

• Benchmark guidance (CIBSE) is not to exceed 28degC for more than 1% of habitable hours

Baseline House

Now (2010 DSY) • 6.6% annual• 28.4% Jul/Aug• Hottest day 25-36degC

Future (2080 HiEm90%)• 50.5% annual• 74.6% Jul/Aug• Hottest day 30-40degC

IDEAhaus

Now (2010 DSY) • 0.2% annual• 1.0% Jul/Aug• Hottest day 22-25degC

Future (2080 HiEm90%)• 12.1% annual• 40.3% Jul/Aug• Hottest day 28-32degC

IDEAhaus - Energy Modelling

Baseline House

• 2010: 4800kWh 2080: 3900kWh energy ‘crossover’ by 2038

IDEAhaus

• 2010: 4000kWh 2080: 2000kWh energy ‘crossover’ by 2048

Energy use(IES) on baseline timber frame housetype for 2010 & 2030, 2050, 2080 Hi-em 90th%tile

Energy use (IES) on IDEAhaus. for 2010 & 2030, 2050, 2080 Hi-em 90th%tile dataset.

Heating/Cooling Energy Use ComparisonIDEAhaus has lower energy use now and in the future and delays the energy ‘crossover’ from heating to cooling dominance by 10 years

IDEAhaus Summary• Overheating and flooding will

become increasingly common and there are signs of change already

• Integral passive cooling design strategies provide a more comfortable & energy efficient house

• The timber frame is protected from flooding by raising the floor slab edges

• Thermal mass is incorporated into the lightweight structures to even out temperature fluctuations

• Mass customisation is used to provide attractive and varied products economically

• Adaptable construction allows for uncertainty

Which way forward?

Which way forward?

IDEAhaus

A Comfortable Home for the UK’s Future Climate Ian McHughGreen Triangle Studio

Presentation to:

ManchesterSchool of Architecture

Mar 2014

Enquiries: green.triangle@btinternet.com