Improving Energy Performance of New and Existing … · Improving Energy Performance of New and Existing Buildings ... • Commissioning –buildings fully commissioned ... • Lighting

Improving Energy Performance of New and Existing Buildings

Dr Kerry J Mashford, Chief Executive,

National Energy Foundation

CIBSE Building Performance Conference

- October 2014

Improving the use of energy in buildings

NEF – improving the use of energy in new and existing buildings

• Management –

existing buildings

• Retrofit and

refurbishment

Making better buildings

• Procurement – new

building

Making buildings better

Dr Kerry J Mashford, CIBSE Building Performance Conference – October 2014

• 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 1

• 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

















InnovateUK– 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


Non-Domestic Building types

The BPE programme buildings fall into 13 building types. Schools and offices are most prevalent.

Courtesy – InnovateUK


Composition of the Performance Gap


Emerging themes – courtesy InnovateUK

• Non-standard hours & unregulated loads (TM22)

• Commissioning –buildings fully commissioned

• Sub-meters and 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

…..what do these tell us?


What can we do about it?

Emerging Themes

Root cause

analysis

Actions to

mitigate


New Building Process Standards

• Respond to relevant emerging themes

• Building Performance Exchange – please share! http://www.nef.org.uk/building-performance-exchange/

• Address root causes

• Implement smart mitigation actions

• Embed in practice; contracts; client ‘pull’


Core Aim Planning 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 CO 2 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 CO 2

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.

4 To 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.

Process standards – New Build


Building

Regulations Design Stage Requirement Evidence Required Guidance on Issue

1




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






• Resultant CO2 emissions

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














homes that will be comfortable and have

low running costs

3






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.




into detailed design, for example the

poor buildability of in order to ensure as

built performance is delivered.


low energy design n/a n/a

Demonstrate how each dwelling 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.


Building

Regulations Construction Stage Requirement Evidence Required Guidance on Issue

1




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






• Resultant CO2 emissions

n/a n/a

Target housing performance indicators

for every plot (minimum of: regulated

energy use, space and water heating cost

and resultant CO 2 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














homes that will be comfortable,

sustainable and have low running costs

3






Bordon

n/a n/a

Check that known 'construction under-

performance risks' list developed at the

design stage have been constructed

correctly.

Completed plot specific checklists to

confirm details constructed as per

designs




into housing designs in order to better

ensure as built performance


low energy design n/a n/a

Applicable at the planning and

design stages only


design stages only


design stages only

AS-BUILT verification of building energy performanceMeasurement Notes Sampling Rate Problems Solutions

Air tightness

Air 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?

Thermography

Themograpic survey of junction

performance

Sample of house types.

Sampling rate increased in types

with more complex detailing - in

line with risk mitigation

approach


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






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



Heat loss measurement

Flux testing of building elements Sample of homes, not house

type dependent. Reduced

sampling rate for construction

types with less risk of

underperformance (factory

manufactured panels, ICF)






Whole dwelling co-heating testing May only be possible for very

small sample of homes. Test

tends to show the impact of the

various contributors to the

perofrmance gap that can be

itentified by other means.

Very time consuming and

therefore expensive. Requires

completion of dwelling.



airtightness testing. Lack of

industry aggrement over

standard testing procedure.

Construction process (is this really a test?)

Photographic record of key concealed

detailing

All dwellings.

OR sample that is increased for

housetypes that require more

complex detailing.

OR required of certain junctions

were ever they occur.

verification of what is depicted

in photos - may be fine for 1 off

Passivhaus but more for an

estate of 4500 dwellings.

Develop an app for tablets

similar to those available to

DEAs for conducting energy

audits? Would help to manage

information generated.

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

Fuel 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 dwelling

Space 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

Subtract DHW energy content

from measured energy reading

on heater meter

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)


circuit(s) supplying direct

electric point of use water

heaters (e.g. electric showers)

N/A - provides direct figure.

Figures may need to be

combined to give total where

point of use heaters co-exist

with central system.

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.


circuit(s) of interest

Deduce energy use figure by

subtracting sub metered

building services use from main

utility meter

Scenario 2 only: Subtract sub

meter(s) on heating system from

main utility meter

Ventilation system energy use

(kWh)

Electricity sub meter N/A - provides direct figure

Heating system efficiency

Overall 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

Calculate ratio of boiler heat

energy output (heat meters) to

energy content of gas supplied

to boiler.

Overall heat pump efficiency in

use (% conversion to heat)

Not essential to measure in order to verify fabric

performance but found to be significantly less than

manufacturers stated figures in EST study - will be a

contributor to the performance gap in terms of fuel

use and thus running cost. Should be confirmed as

measure of installation / commissioning quality

Electricity sub meter on

monoblock heat pump system

Electricity sub meters on all

components of split heat pump

system including immersion

heaters

Calculate ratio of total system

heat energy output (heat

meters) to electrical energy

supplied to system.

Renewable energy system contribution

Electricity generation (kWh) Main utility generation meter for

FIT

Built in system generation meter N/A - provides direct figure

Heat generation (kWh,

deduced from ΔT and flow)

Heater meter across heat

generator flow and return

N/A - provides direct figure

Internal environmental conditions

Internal temperature (°C) Essential to measure in order to normalise measured

space heating energy use back to a standard set

point temperature. Ideally need an indication that

temperature in dwelling is reasonably uniform, i.e.

multiple loggers.

One or more temperature

loggers, initially in the room

containing (main) heating

system thermostat


Internal Relative Humidity (RH,

%)

Proxy for ventilation strategy (system) performance

and indoor air quality.

One or more RH loggers, initially

outside rooms where moisture is

generated


Internal CO2 concentration

(ppm)

Proxy for ventilation strategy (system) performance

and indoor air quality.

One or more loggers, initially

living rooms, then bedrooms


Window and door opening (%

of time, hours)

Required to identify additional ventilation losses

caused by occupant behaviour.

Sensors on each window and

door

N/A - provides direct data

Mechanical ventilation system

flow rates (m3/hour)

Required to identify ventilation losses so that they

can be separated from fabric losses and verify

performance of the system.

High end systems can confirm

flow rate, otherwise difficult to

measure and may need to be

taken as commissioned flow

rates

N/A - provides direct data

External environmental conditions

External temperature (°C) Essential to measure in order to normalise measured

space heating energy use back to a standard set of

climate data.

Single temperature logger. N/A - provides direct figure

External Relative Humidity (RH,

%)

Can be used to explain internal RH under certain

conditions.

Single RH logger. N/A - provides direct figure

Solar radiation (hours) Can be very site specific, useful to determine likely

level of passive heating and the reasons for

overheating.

Improving Energy performance in Existing Buildings - VolDEC

• Legal & General, Building Energy Solutions, National

Energy Foundation

• Not for profit scheme to benefit whole industry

• Separates landlord and tenant energy

• Piloted on 16 multi-tenanted offices – extending to

retail next

• Uses same methodology as statutory DECs with

extended G ratings for greater differentiation


VolDECs – Why?

• Provides landlords and tenants with comparative energy performance of

the areas they control

• Highlights building energy performance

• Provides a clear driver for improving performance

• Gives reputational and financial value to energy performance

• Provides a simple soft-start, leading building operators towards more

sophisticated benchmarking

• Encourages greater retrofitting and energy related improvements,

resulting in better buildings, economic activity and jobs

Aims – • to established a consistent methodology and QA across the industry • to support the development of improved and relevant building energy

benchmarks – e.g. type 4, scenario 5, office.


VolDEC - Method and benchmarks


www.nef.org.uk

[email protected]

Improving the use of energy in buildings

Documents

Improving Energy Performance of New and Existing … · Improving Energy Performance of New and Existing Buildings ... • Commissioning –buildings fully commissioned ... • Lighting