Historic House - Oxford Green Week · 2018-12-06 · Professor Rajat Gupta Director of Oxford Institute for Sustainable Development ... Greening your historic home event, 21 June

Historic House Oxford Retrofit

21 June 2017

Adrian Kite - Ridge

Oxford Retrofit Project

Prof Rajat Gupta – Oxford Brookes

Measurement, Modelling and Monitoring

Introduction to Technology Strategy Board

(TSB) Retrofit for the Future

Retrofit for the Future

• Government target to reduce greenhouse gas

emissions by ....80% by 2050

• 80% of Houses in the UK by 2050 are the existing

....houses we have now

• Limited affect of Carbon Neutral New Build

• Technology Strategy Board competition challenge

....how to achieve 80% reduction in CO2 of the

....existing housing stock from 1990 levels

Retrofit for the Future


Oxford City Council house

66% reduction from fabric improvement,

increased to 75% from appliances and lighting

increased to 85% solar thermal and PV

Fuel bills reduced from £600/yr to £150/yr

Fit and Forget, low maintenance focus

Practical tried and tested technologies

User centred approach

Improve health and comfort

Identify learnings and apply to wider social housing


• Jericho - Oxford City

• SE – NW orientation

• Decorative brickwork on front elevation

• Victorian 2 bed solid walled end-terraced house

• Gable wall / party wall

• Rear cavity wall / flat roof rear extensions

• Existing Double Glazing

• Cold House – Especially First Floor Extension

• Cold internal masonry walls

• Tenant at home full time





Construction Phase:

• Strip out

• Mould / Damp

• Rotten roof / floorboards

• Knock through wall

• Insulation

• Windows

• Airtightness

September - December 2010

• MVHR

• PV’s

• Heating / Hot Water

• Internal drying rails

• Monovent / Sunpipe

• Wet Room

• Monitoring

.


• External Insulation

• Internal air tightness





• PV’s & Solar Thermal

Evacuated Tubes

• Triple glazed

windows

Result

• Warm

• Quite

• Bright

• Good air quality

• Happy Occupants

• 2 Years Monitoring


Insights and learning from the

monitoring and evaluation of the

Oxford Whole House Retrofit project

Professor Rajat Gupta Director of Oxford Institute for Sustainable Development

[email protected]

Greening your historic home event, 21 June 2017, Oxford

Case study dwelling: Victorian terrace

Victorian solid wall end-

terrace

Year built Pre-1919

Area 78 m2

Occupancy 2 adults

Unique issues Difficult to heat, poor daylight,

preserve street façade

Retrofit focus High efficiency fabric, increase

natural light

Fabric

upgrades

Internal, external, and cavity wall

insulation; floor and loft

insulation; triple glazing

Heating & low/

zero carbon

tech.

Condensing combi-boilers, solar

hot water, PV

Ventilation MVHR

Retrofit

process

Tenants decanted

Occupant feedback: in-use characteristics

Garden and central location of the house were positive

features.

Space heating: Occupants complained about a 'cold'

house which was difficult to heat due to lack of

insulation and rising fuel costs.

• Heating system responsive, but inadequate

• Occupants adapted by wearing extra layers of clothes

indoors

Future adaptability - occupant with health/ mobility issues

How did the Pre-refurbishment M&E

impact the interventions?

Pre-refurbishment analysis results Interventions

Poor levels of daylight;

Average daylight factors < 1

Roof lights incorporated in design

with good low U-values to

minimise heat loss

Poor indoor air-quality in the house Refurbishment will lead to a well

sealed house, further reducing

natural air pathways; Incorporate

mechanical ventilation; monitor

MVHR

Windows were monitored for 28 days

and found to be opened on an

average for only 4 days

Un-insulated fabric Highly insulated fabric;

Triple glazed windows;

Efficient heating systems

Difficult to heat house to comfortable

temperatures

Lower than average gas bills –

careful occupants

Post-refurbishment monitoring and POE

Evaluation of energy consumption

56

57

143

45

43

121

56

17

83

23

16

32

0 50 100 150 200 250

Post-retrofit actual (2011)

Design target (SAP)

Pre-retrofit actual (2008)

Post-retrofit actual (2011)

Design target (SAP)

Pre-retrofit actual (2008)

Mo

de

rnV

icto

ria

n

kWh/m2/yr

Gas

Electricity

(75% reduction over TSB baseline)

Occupants, activity pattern and energy use

Questionnaire survey

Occupant feedback: What works?

Occupant Feedback from interviews & questionnaires

“Comments” – Positive aspects Key highlights

House warms up very quickly. We set the

thermostat much lower now.

No noise problems from neighbours or the

outside.

We don’t notice the difference in size

caused by the insulation in the ground

floor;

Brilliant for drying the washing; The wet

room in the ground floor is very useful

No draughts; cheaper bills; this room is a

lot lighter; it used to be terribly dark.

Excellent lighting all around, especially in

kitchen.

Nicer environment to live; close to

hospitals, shops and school.

• House retains heat; heating

system responds fast;

• Reduction in noise concerns;

• Change in room size not

noticeable due to increased

light levels & improved design;

• Clothes dryer – success;

• No draughts;

• Cheaper bills;

• Good location

Occupant feedback: What hinders? Occupant Feedback from interviews & questionnaires

“Comments” – Problem areas Key highlights

If we’re reading or doing any craft work, we

use two lamps (self-bought) which are quite

bright and can be dimmed.

Still learning the best way to use some

systems like cooling & heating other than

opening windows/doors.

Having lost the attic storage, the spare

bedroom has now become the store and we

haven’t had space to have visitors over.

The MVHR vents are very noisy and it can

change pitch on a windy day.

No display for PV.

Two windows (in the sun) get heated up

during the day in summer and they expand;

making it impossible to close till it cools

down!

Narrow kitchen; rain shelter above main

door would have been useful.

• Energy efficient lighting not suited to

specific tasks

• Ventilation controls – learning in

progress

• Lack of storage space – design issue

• MVHR – noisy, confusion on control

• PV – no display systems

• Issues with opening/closing of windows

• Rain shelter above main door

The deep retrofit reduced energy consumption and carbon

emissions, while improving comfort and satisfaction for the

occupants. Occupants were more engaged-which led to

greater success

Monitoring & Evaluation is a tool for continuous learning and

improvement. Helps to realise actual energy savings.

Helps to reduce the performance gaps between ‘as designed’

and ‘in-use’ performance

Lessons and challenges

Think of the user interface

issues with new

technologies.

Sustained occupant

motivation towards reducing

energy consumption is

important (involve them in

the process).

Thank you for listening

Documents

Historic House - Oxford Green Week · 2018-12-06 · Professor Rajat Gupta Director of Oxford Institute for Sustainable Development ... Greening your historic home event, 21 June