Building Sustainability Dr Kerry J Mashford, Chief Executive, National Energy Foundation Improving the use of energy in buildings

Building Sustainability

Dr Kerry J Mashford, Chief Executive, National Energy Foundation

Improving the use of energy in buildings

• Business

• Climate

• Society

• Individuals

Why sustainable buildings- who benefits?

Dr Kerry J Mashford, MK50 – Sept 2015

The Performance Gap - in theory, theory and practice are the

same; in practice they aren’t!


Buildings often don’t perform as expected –

Source : Bill Bordass based on data from Better Buildings Partnership


• Probe 1995 -2002

• exemplar buildings post occupancy – actual twice as much as design

The scale of the problem

(http://www.cibse.org/index.cfm?go=page.view&item=2481#Probe 1)


http://www.cibse.org/index.cfm?go=page.view&item=2481#Probe%201

• Carbon Trust studies – (Low Carbon Buildings Accelerator and Low Carbon Buildings Programme)

• Indicate actual energy use up to 5 times higher than specified

http://www.carbontrust.com/media/81389/ctv038-low-carbon-refurbishment-of-buildings-management-guide.pdf

The scale of the problem


http://www.carbontrust.com/media/81389/ctv038-low-carbon-refurbishment-of-buildings-management-guide.pdf

Innovate UK– Building Performance Evaluation Programme

• Over 100 new build projects + 3 refurb

• 49 non-domestic studies, 56 buildings

• 366 dwellings (developments 3989 dwellings)

• Completion and early occupation / in-use

• Energy use typically 2.5- 4.5 times predicted

2010 - 2014


Domestic energy performance gap


Non-domestic energy performance

Performance degradation over time


What if house builders were held to account for the performance of the homes they build?


Expected energy use

Save costs, energy and carbon - Improve comfort

How does the performance gap arise?


Building Performance Evaluation - measuring and verifying performance


Emerging themes – courtesy Innovate UK

• Non-standard hours & unregulated loads (TM22)

• Commissioning – not a single building fully commissioned

• Sub-meters & reconciliation – not functioning or understood

• BMS – training, complexity, functionality, commissioning

• Controls – complexity, operating instructions and labelling

• Lighting – too much, zoning deficiencies and lack of control

• Fabric performance – specification and construction

• HVAC – integration and control of multiple systems

• Renewables – installation, operation and maintenance

• Energy strategy not properly implemented


How does the performance gap arise?

Successful execution of each stage of building delivery depends on decisions made at earlier stages – we need a whole systems approach

So, how can it be solved?


Core AimPlanning Policy

Building Regulations

Planning Stage Requirement Evidence Required Guidance on Issue

1

To ensure that there is someone in the project team who is accountable for the

final energy performance of the completed homes.

n/a n/a

Named individual from developer appointed as 'sustainability champion' responsible for delivering verified 'as-built' performance and demonstrating

this to Whitehill and Bordon

Confirmation of who the sustainability champion is and of their standing within

the developer

The sustainability champion is expected to be the main point of contact with W&B regarding compliance with W&B Housing Performance Verification Policy

2

To ensure it is clear to all stakeholders what performance indicators the finished homes will be judged on:

• Regulated energy use• Annual space and water heating cost

• Resultant CO2 emissions

n/a n/a

Chosen target housing performance indicators for every plot (minimum of: regulated energy use, space and water

heating cost and resultant CO2

emissions) must be prominently displayed on all planning stage information and published literature or advertising related to the development.

Copies of planning submissions with stated performance indicators shown. Copies of any marketing information published to show housing performance.

Ensuring awareness of the expected energy performance of the homes to all involved in their development and delivery will help to prioritise as-built performance as an important part of the

development process.Ensuing wide public awareness of the performance of the homes in W&B will promote the sustainability credentials of the town and empower buyers to choose homes that will be comfortable and have

low running costs

3

To ensure that knowledge and understanding of 'as-built' performance

gained from recent projects and research programmes informs design and delivery of homes in Whitehill and

Bordon

n/a n/a

Undertake a review of past experience, from published case studies of existing developments and ensure that the proposed planning stage design has been informed by earlier findings.

Show how past learning has been incorporated into the planning stage

design - to be reviewed at a design workshop with NEF(?)

There is a growing body of evidence that has been published that provides useful information that could be incorporated into planning stage design, including layout, in order to ensure as built

performance is delivered.

4To incorporate good practice passive

low energy design

Check if this is covered in any way by existing policy.

n/a

Demonstrate how each parcel of land has been designed to provide a good daylighting and useful solar gain into

main living areas

Demonstrate understanding of solar access with regard to sun angle through the year and relationship between useful

gain vs. overheating

A passive design strategy report is required that cover both site layout and

house type designs and which demonstrates how solar access has been

considered for every dwelling.

Solar gain can provide approximately one third of space heating in well designed and built homes that have a very high quality thermal envelope.

Planning

Design

Construction

Assured Performance Process – to remove/mitigate performance risks



Design Stage Requirement Evidence Required Guidance on Issue

1

To ensure that there is someone in the project team who is accountable for the

final energy performance of the completed homes.

n/a n/a

Named individual from developer appointed as 'sustainability champion' responsible for delivering verified 'as-built' performance and demonstrating

this to Whitehill and Bordon

Ongoing confirmation of who the sustainability champion is and of their

standing within the developer

The sustainability champion is expected to be the main point of contact with W&B regarding compliance with W&B Housing Performance Verification Policy

2

To ensure it is clear to all stakeholders what performance indicators the finished homes will be judged on:

• Regulated energy use• Annual space and water heating cost


n/a n/a

Target housing performance indicators for every plot (minimum of: regulated energy use, space and water heating cost and resultant CO2 emissions) must be prominently displayed on all design stage information and published literature or advertising related to the

development.

Copies of planning submissions with stated performance indicators shown. Copies of any marketing information published to show housing performance.


development process.Ensuing wide public awareness of the performance of the homes in W&B will promote the sustainability credentials of the town and empower buyers to choose homes that will be comfortable and have

low running costs

3

To ensure that knowledge and understanding of 'as-built' performance

gained from recent projects and research programmes informs design and delivery of homes in Whitehill and

Bordon

n/a n/a

Undertake a review of past experience, from published case studies of existing developments and ensure that the design and detailed design has been informed

by earlier findings.

Show how past learning has been incorporated into the design of each dwelling, include detailing around

feature known to cause underperformance such as thermal bridging, air leakage, thermal bypass etc. - to be reviewed at the design

workshop with NEF(?)

Produce log sheet of 'Design Risks'* (These to be developed as part of WPC1) for each house type based on details present in each type and previous issues that have occurred with that detail (informed by review), and what must be done to ensure the detail performs as

intended.

There is a growing body of evidence that has been published that provides useful information that could be incorporated into detailed design, for example the poor buildability of in order to ensure as

built performance is delivered.

To incorporate good practice passive

Demonstrate how each dwelling has been designed to provide a good daylighting and useful solar gain into

main living areas. Demonstrate

A passive design strategy report is required that cover both site layout and

Solar gain can provide approximately one third of space heating in well



Construction Stage Requirement Evidence Required Guidance on Issue

1

To ensure that there is someone in the project team who is accountable for the final energy performance of the

completed homes.

n/a n/a

In addition to the named individual from developer appointed as 'sustainability champion' with overall responsible for

delivering verified 'as-built' performance, an 'as-built performance champion' should be appointed who is based on site. The individual appointed should have both design and site quality control experience and be provided with sufficient time and seniority to enforce quality issues that impact as-built

performance.

Confirmation of who the 'sustainability champion' and 'as-built performance champion' are, their standing within the developer and in the case of the latter, that a significant portion of their job role is to enforce as built performance.

The 'as-built performance champion' is responsible for ensuing that the design intent is accurately built on site and thus the buildings have the potential to perform as designed. For any but the smallest site it is unlikely that this could reasonable be added to the numerous existing duties of the overall site

manager.

2

To ensure it is clear to all stakeholders what performance indicators the finished homes will be judged on: • Regulated energy use• Annual space and water heating cost


n/a n/a

Target housing performance indicators for every plot (minimum of: regulated energy use, space and water heating cost

and resultant CO2 emissions) must be stated on all house type drawings and marketing in relation to development

sites in the EcoTown

Copies of house type drawings with stated performance indicators shown. Copies of any marketing information published to show housing performance.


development process.Ensuing wide public awareness of the performance of the homes in W&B will promote the sustainability credentials of the town and empower buyers to choose homes that will be comfortable, sustainable and have low running costs

3

To ensure that knowledge and understanding of 'as-built' performance gained from recent projects and research programmes informs design

n/a n/a

Check that known 'construction under-performance risks' list developed at the design stage have been constructed

Completed plot specific checklists to confirm details constructed as per

designs

There is a growing body of evidence that has been published that provides useful information that could be incorporated into housing designs in order to better

Construction

Design

AS-BUILT verification of building energy performanceMeasurement Notes Sampling Rate Problems SolutionsAir tightnessAir tightness testing as part of forensic investigation, in conjunction with thermography and or smoke

Sample of house types in early stages of overall delivery to understand detailing risks in each design

Requires completion of dwelling including services. Potentially time consuming

Uncalibrated blower door type machine for depreasurising building in oder to falut find.

Air tightness measurement intermediate stages

Optional, only needed as part of quality management when high level of airtightness is required (e.g. Passivhaus)

Time taken for testing, must be sequenced into build programme.

Possible use of pulse measurement technique?

Air tightness measurement on completion

All dwellings - standard for speculative developers

Possible use of pulse measurement technique?

ThermographyThemograpic survey of junction performance

Sample of house types. Sampling rate increased in types with more complex detailing - in line with risk mitigation approach

Requires completion of dwelling including heating system. Restrictions on time of day, time of year. Possible liaison with airtightness testing.

Themograpic survey of element performance

Sample of homes, not house type dependent. Reduced sampling rate for construction types with less risk of underperformance (factory manufactured panels, ICF). Increased sampling rate for higer

Requires completion of dwelling including heating system. Restrictions on time of day, time of year. Possible liaison with airtightness testing.

Themograpic survey of services performance

Sample of homes, not house type type dependent. Increased sampling rate for non standard services (heat pumps, solar thermal, MVHR, underfloor heating etc.) - in line with risk mitigation approach

Requires completion of dwelling including heating system.

Heat loss measurement

Construction process (is this really a test?)

IN-USE verification of building energy performanceMeasurement Notes Scenario 1 Scenario 2 Scenario 3 Data manipulationFuel Use

Gas consumption (m3, converted into kWh)

Potentially includes space heating, water heating, cooking. Can be used to avoid sub metering all uses downstream of the utility meter.

Main utility meter N/A - provides direct figure

Electricity use (kWh) Potentially includes space heating, water heating, cooking, lighting and appliances. Can be used to avoid sub metering all uses downstream of the utility meter.

Main utility meter N/A - provides direct figure

Energy use by application within dwellingSpace heating energy use (kWh, deduced from ΔT and flow if required)

Essential measurement required for comparison to design prediction

Heater meter across boiler main flow and return. Heat metering of DHW energy content.

Heater meter across heat pump main flow and return. Heat metering of DHW energy content.

Electricity sub meter(s) on circuit(s) supplying direct electric heaters

Water heating energy use (kWh, deduced from ΔT and flow if required)

May be essential to measure this in order to determine space heating energy use, depending on services configuration. Otherwise nice to have but largely dependent on occupancy and behaviour. Heat meter flow component can be used to measure DHW use.

Heater meter across rising main and DHW output from water heater (combi DHW feed, DHW cylinder)

Electricity sub meter(s) on circuit(s) supplying direct electric point of use water heaters (e.g. electric showers)

Lighting and appliance energy use (kWh)

This should be measured because it ultimately ends up as heat in the dwelling so should be added to measured space heating energy use during the heating season to determine 'real' space heating energy use for the dwelling.

Electricity sub meter(s) on circuit(s) of interest

Deduce energy use figure by subtracting sub metered building services use from main utility meter

Ventilation system energy use (kWh)

Electricity sub meter N/A - provides direct figure

Heating system efficiencyOverall boiler efficiency in use (% conversion to heat)

Not essential to measure in order to verify fabric performance but if significantly less than manufacturers stated figures will be a contributor to the performance gap in terms of fuel use and thus running cost

Main utility gas meter where boiler is only consumer of gas

Gas sub meter on boiler where gas cooking / fire is used

Renewable energy system contribution

Internal environmental conditions

External environmental conditions

In-use

As-built

Human factors


Sustainability and Occupants

• Productivity in offices, learning and concentration, recovery rates in hospitals, dwell time in retail etc. can all be impacted by:• inherently ‘good’ environments and

• good interfaces between the buildings and occupants


Early work – late 1990s

• Contributors to wellbeing• Feel - Thermal comfort, physical touch points

• Sight - Lighting levels, natural light, views

• Sound – Acoustics, noise

• Smell, taste - Air quality, drafts

• Perception – control, tolerance, safety, community

• Plants, water

• Colour schemes

• Proportions, layout


Metrics

• Indicators • Absenteeism

• Staff turnover

• Feelings of comfort

• Reported stress levels

• Recovery rates

• Medication levels

• Pride

• Self-worth

• Concentration and learning


BPE programme• Building Use Surveys

• Walkthrough inspections

• Occupant interviews

• Review of manuals and guidance

• Fully automated systems lead to frustration• Often don’t work as expected

• Difficult to adjust

• Susceptible to failure and its consequences

• Finely balanced / optimised – little forgiveness

• Local manual control preferred


Emerging themes 1– courtesy Innovate UK

• BMS –complexity; functionality; commissioning; training

• Controls – complexity; operating instructions; labelling

• HVAC – integration and control of multiple systems

• Portable devices


Emerging themes 2– courtesy Innovate UK

• Lighting – too much; zoning deficiencies; poor control

• Renewables and MVHR – installation; operation and maintenance

• Energy strategy - not properly implemented, e.g. lead and secondary heating


NEF project experience – occupant behaviour

• Less ‘community spirit’ in affluent neighbourhoods where residents work long hours

• Energy literacy varies across all sectors of society

• Access to open house examples improves action

• Visual comparators drive home the message

• Frequent(ish) reinforcement helps sustain

• Make it easier to do the right thing than the wrong thing – e.g. recycling


Using DECs to support behaviour

• Promotional device, clear indicator

• Enhanced when combined with promotional campaign

• Engagement and culture change

• Competitions between buildings

• Live dashboards

• Simple message easily included in reports and documents

• Clear indication of use and trends


The issue for Landlords and Tenants

• No split between Landlord and Tenant

• DEC shows whole building performance, one DEC.

• Cannot show improvements (or not) in what each control

• DECs use one benchmark for all offices, not a good match for many office types

• Many offices are ‘stuck’ at G, cannot show improvement


• DECC study concludes DECs can aid

behavioural change, but

• DECs would benefit from:

• better differentiated benchmark (not

one size fits all offices) and landlords /

tenants can’t see their energy use.

• more granular rating scheme

• VolDEC addresses these issues http://

www.nef.org.uk/service/existing-buildings/

energy-management/voldecs-voluntary-dis

play-energy-certificates

DECs and occupant behaviour


http://www.nef.org.uk/service/existing-buildings/energy-management/voldecs-voluntary-display-energy-certificates





www.nef.org.uk

[email protected]

Improving the use of energy in buildings

Documents

Building Sustainability Dr Kerry J Mashford, Chief Executive, National Energy Foundation Improving the use of energy in buildings