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Retrofitting SusCon 3 Domestic (CPD) G#356 N#357

By 9 June 2014January 25th, 2021CPD, Encyclopaedia, Files, Refurbishment
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Retrofitting SusCon 3 Domestic CPD

GBE > Encyclopaedia > Files > CPD > Topics > Refurbishment > G#356 N#357

Retrofitting SusCon 3 Domestic CPD

GBE CPD Metadata

  • File Name: Retrofitting SusCon 3 Domestic CPD S48 PDF show
  • File Type: PDF of PPT
  • File Size: PDF Show: 353 kb
  • Number of Slides/Pages: PDF Show: 48 Slides
  • Course: Retrofitting Practical Toolkit for Architects CPD 2010 Programme Sustainable Construction
  • Course Authors: Brian Murphy of GBE and Cath Hassell of ech2o…
  • Created for: Retrofitting Course SusCon RIBA S/SE Architects CPD
  • Sponsored by SEEDA, ESF, BSSP;
  • Presented to: Retrofitting Course SusCon RIBA S/SE Architects CPD
  • Author: BrianSpecMan aka Brian Murphy ONC HNC Construction BSc Dip Architecture (Hons+Dist)
  • © GBE GBL GBC NGS ASWS 2010 – 2014
  • Created: 18/05/2010
  • Revision: 5
  • Updated: __/__/2014
  • Previously published on Scribd: 20/05/2010
  • Scribd reads: 511 @06/01/2013
  • Tags: CPD Course, Retrofitting,
  • ProductSets: Methods of Construction, Materials, Building Elements,
  • UserGroups: Students, Architects, Assistants, Technicians, Structural Engineers, Constructors
  • Scope: Retrofitting Domestic Property
  • Course: Retrofitting Practical Toolkit for Architects CPD 2010 Programme Sustainable Construction

GBE CPD Content

(without images; See the slide show for the pictures)

Retrofitting Practical Toolkit for Architects

GBE SusCon Course

3 Retrofitting Domestic Properties

  • Winchester: 19th May 2010 & Guildford: 20th May 2010
  • Brian Murphy of NGS
  • Cath Hassell of EcH2O

Retrofitting: Domestic Properties

  • Design issues: Building Performance:
  • ‘Sarah Beeny effect’
  • Domestic use patterns and design response
  • Conservatories v Solar spaces
  • Glazing issues
  • Materials and methods,
  • Insulation: Internal or external
  • Party walls & Party floors, Internal walls
  • Airtightness
  • Heating
  • Case Study
  • Flood Risk

Domestic use patterns: impact on fabric & services

  • Demands: morning and evening
  • Aged population: 24 hours heating
    • Winter: cheap Spanish holidays
  • Fuel poverty: 0 hours
  • Insulation, Insulation, Insulation
  • Smoothing out the peaks and troughs
  • Morning sun
  • Collect heat in day for use in evening
  • Expose thermal mass
  • Avoid drafts

Design issues:

  • 80% reduction in carbon consumption
  • Passive solar design:
    • Capture heat in winter
    • Ventilate in summer
  • Exploit thermal mass
  • Passive solar roofs with Renewables

‘Sarah Beeny effect’

  • TV presenter:
  • Series: doing houses up for profit
    • Setting up business to do more in future
    • Never go beyond the basics
    • Or profit margins eroded
  • We have to get beyond her then philosophy:
    • Profit before Planet
  • Moving on from Sustainable enterprise
    • to Sustainable outputs
  • Now does ‘love match-making’ website
  • But wrote a ‘Beeny Greenie’ guide

Achieving 80% is easy!

  • Usable Buildings Trust Bill Bordass
  • See Slide

GBE Link

Whole House Plan

  • 80% reduction target at end
  • If it can’t be done in one hit:
    • Phased/zoned approach
  • Phases:
    • Insulation first, EcoBling last
    • Supports & Pipes in first phase for EcoBling in later phase
  • Zoned: room by room
    • Spare room for decanting: room by room
  • Early services:
    • But insulated linings, before kit, complete linings later

Space for insulation?

  • Victorian
    • Generous rooms sizes,
    • small rear extensions for bathroom & kitchens
  • Peabody estate
    • Generous flat and room sizes
  • Parker Morris (PM) standards
    • Rooms fit required furniture with no slack
    • Stores took all the slack
  • Post Parker Morris
    • Too small for most things
  • LTH, CfSH, DDA, PM+10%
    • Generous + dictated layouts, difficult

Space for insulation?

  • LTH, CfSH, DDA:
    • Bathrooms & Kitchens:
    • difficult if not impossible to lose space for insulation
  • Staircases not easy to move away from external walls
  • Difficult & very disruptive to add internal insulation
  • External insulation may be dictated

Whole house replanning

  • If there is an opportunity to re-plan the use of the rooms of the house take it
  • Consider orientation
    • Consider which rooms what to be on the east, south and west
    • Bedrooms east not west
    • Living rooms south to south west
  • Simplify bathroom and kitchen plumbing
    • Reduce hot water supply distances
  • Make room for insulation

Whole house insulation

  • Insulation continuity: No compromises
  • Thermal bridging
    • Heat will find a way out of there is one
    • Add thermal breaks
    • Remove thermal brides
    • Wrap up thermal bridges
  • Thermal bypass
    • Cavities are places for heat to escape to
    • Insulate all cavities
    • Insulate all ducts/housings/boxing in

Whole house weather tightness

  • Draft lobbies on all external doors
    • Front, rear and side
  • Internal or external?
    • External if possible
    • Internal may create a cold bridge
  • Combine lobby with solar space?
    • Add solar gain absorbing walls and floors
    • Add thermal mass to those walls
  • Glazing to trap the heat in winter
  • Ventilation top and bottom to vent in summer

Conservatories v Solar spaces

  • Conservatories
    • Add to living space and get used all year
    • Often create a redundant space behind
    • Add to heating demands in winter
      • Most (80%) in UK are heated
        • Squandering energy
      • Often open to house
        • despite the building regulations
        • Big energy drain
    • No ventilation
      • Must be top and bottom
    • Add to overheating in summer
      • Many are offering opaque roofs now

Conservatories v Solar spaces

  • Solar spaces
    • Are solar traps
      • Insulating glass to trap heat in winter
      • Once warm then let heat into house
    • Surrounded by thermal mass
      • Absorb heat and store until evening
    • Windows in sloping and vertical faces
      • Cooling ventilation in summer
    • Can serve upper and lower floors
      • Used as weather sheltered outdoor space in winter

Window & Doors

  • New windows & doors to align with insulation
  • New insulation to wrap to windows & doors
  • External Insulation required windows set at outer face or reveals insulated as well as walls
  • Internal Insulation required windows set at inner face or reveals insulated as well as walls
  • A good window placed badly can perform as badly as a poor windows placed well

Glazing issues

  • Thermal comfort
    • Aim for 17 degrees inside face of glass
    • Close (3 degrees) to room temperature
    • No discernible coolth down draft
  • Warm feet:
    • warm and happy people
  • Passivhaus accredited windows will achieve this

Upgrading windows

  • Secondary glazing
    • Improved U value
    • Improved thermal comfort
    • Improved airtightness
    • Improved acoustics
    • Improved security
    • Improved utility
  • Allow original window to perform as intended
    • Air leaky

Refurbish windows

  • Replacement glazing
  • Improved U value
    • Modify beading
  • Improve airtightness of sashes and casements
  • Refurbish ironmongery
  • Refurbish counter weights
  • Redecorate: Whilst out of opening, all round
  • Remove years of paint jamming sashes

Services & Void Insulation

  • As heating demands tumble
  • Hot water heat losses become very important
  • Cold water being warmed becomes important
  • Lagging of pipes seems to be difficult for plumbers
  • Labour intensive cost cutting opportunity
  • So fully insulate the voids they run in
    • not the pipes
  • Every opening up must be insulated before closing

Multi trades

  • Insulation
    • Renderers must learn insulated render
    • Plumbers must learn insulating pipes or voids
    • Electricians must learn insulating cable or voids
  • Air tightness
    • Kitchen fitters must learn air tightness
    • Bathroom fitters must lean air tightness

Wall Insulation:

  • Cavity walls: “easy to insulate”
    • insulation is easy but wholly inadequate
  • Solid walls: “difficult to insulate”
    • Internal and/or external insulation
    • Internal insulation and dry-lining
    • External insulation and render or cladding
    • Not difficult, just less easy

Materials, k values and thicknesses

  • See Slide

Insulation Thickness

  • Different k values
    • Reducing thickness
    • High cost of thin insulation
  • Reasons for choosing worse k value materials
    • Carbon Sequestration: plant based
    • Decrement Delay: dense materials
    • Moisture management: plant & wool based
    • Wind and Air Tightness: dense materials
  • T&G jointed
    • Acoustic performance: dense materials

Building Performance Current/Recent Construction

Recent Building Principles pre 1919

  • See Slide

Recent construction

  • Basic cavity wall
    • Absorbent brick
    • Cement mortar joints
    • Thin outer leaf, cavity, inner leaf
    • Ties between leaves with drips
  • Wind driven rainfall hits wall
    • some runs down surface
  • No shedding details except sills

Recent construction

  • Some absorbed
  • –Some drawn through runs down inner face of external leaf
  • –Some evaporates inwards
  • –Cavity ventilated and drained
  • Damp proof course in wall leaves and membrane in floor, linked
  • Ground water not drawn upwards
  • Wall absorbs internal moisture,
  • –Drawn through and evaporates into cavity
  • –Heat consumed to dry building

Current Building Principles

Current Construction with Insulated cavity

  • Partial Fill
    • Permeable insulation needs breather membrane in cavity
    • To maintain insulation performance
    • Closed cell or foil faced traps moisture
  • Full fill
    • Outer face is moist
    • Must be hydrophobic
    • And not offer moisture transport

Current Building Principles

  • See Slide

Recent Building Principles

Recent Constructions

  • Timber framed cassette panels
  • Vapour barriers inadequately sealed at services and abutments
    • Moisture enters the panels
  • Rock or glass wool insulation
    • Hydrophobic insulation
  • Moisture goes to timber until it escapes
  • Moisture goes to unfilled cavity
  • Thermal bypass:
    • heat into cavities,
    • air movement heat loss
    • ventilation heat loss

Now Constructions if you want a Future

  • Breathing walls
    • Airtightness layers
      • not vapour barriers
      • Moisture permeable
    • Wind tight outer layers,
      • moisture permeable
    • Resistance 5:1 Inner : Outer
    • Hygroscopic insulation
      • Absorbs moisture into fibres not into insulation trapped air space
      • Absorbs moisture aways from timber

Where to thermally insulate External wall?

  • Cavity walls: in the cavity,
    • but not enough needs much more
  • Solid walls:
    • Outside: optimum exposed thermal mass inside
      • if architecture permits
      • If T&CP permits
      • If not too many services and signs attached
    • Inside: hides thermal mass
      • If plan layouts permit
        • Kitchens and Bathrooms
        • If staircase not at external wall


  • Older properties may have architectural merit
  • Terraces may be designed to be seen as a terrace
  • Crumble details at eaves, corners and openings may discourage over cladding and external insulation
  • Internal skirting, cornice, dado, wall linings may discourage internal insulation

Where to thermally insulate Roof?

  • Lack thermal mass: risk overheating
    • Add decrement delay to protect from summer radiant heat from sun
  • Insulation between rafters: cold bridge through insulation
    • Add insulation above the rafters
  • Avoid insulation below the rafter
    • Prevent cold bridging through insulation close to inside face

Where to thermally insulate Suspended Ground floor?

  • Insulation between joists: cold bridge through insulation
    • Add insulation below the joists
  • Avoid insulation above the joist
    • Prevent cold bridging through insulation close towards inside face
  • Wind/air tightness important

Where to thermally insulate Ground Bearing floor?

  • Insulation below floor:
    • Disruptive for occupants
    • Expensive and Wasteful
    • New concrete floor: high carbon content
    • Keep insulation dry: use DPM to wrap it up
    • Exposes thermal mass
      • But what follows?
      • Does it cover it up?
    • Expanded PS or Cellular Glass in bitumen

Where to thermally insulate Ground bearing floor?

  • Insulation above floor:
    • Potentially disruptive for occupants
  • Relay carpets & other floor finishes?
    • Thickness is an issue
  • Thresholds or door modifications?
    • Hides thermal mass
  • Needs to insulate well to compensate
    • VIP Vacuum Insulated Panels
  • Modular: needs cut insulation at perimeter
    • Aerogel quilt or bonded to board

Party Floors

  • Hot air rises
    • Air-paths bad for airtightness, acoustics, thermal and fire
  • Thermal conduction all directions
    • Thermal bridges are bad for heat transfer and acoustic transfer
    • Thermal breaks are better
  • Acoustic isolation and insulation
    • Offers some thermal breaks and thermal insulation

Party walls

  • Are not neutral
    • Building Regulations: Assumes they are,
    • Acoustics takes priority
    • No U value required
  • this is going to change
  • Solid walls
    • One person does not heat home
      • Steals heat from neighbours
  • Large Surface Area
    • Thermal mass potentially exploited if not insulated

Party walls

  • Timber frame
  • –Building Regulations Part L permits insulation in only one leaf
  • –No insulation from 50% of flats or houses
  • –Blown cellulose fibre into stud zone
  • Cavity walls
  • –Stack effect chimney to roof, thermal bridge at roof level
  • –Heat could be collected and used

Internal Partitions

  • Insulate them
    • To stop excess heat from one side warming the other
    • To stop ‘kept cold’ room(s) cooling adjacent ‘kept warm’ room(s)
    • Fill hollow partitions (blown cellulose fibre)
  • Fit internal door closers
    • Manage heat flows


  • Dry trade:
  • –Plasterboard and skim can be airtight
  • –But provides cavities for air to flow around in
  • –Also air leaky at skirting and ceiling level
  • Wet trade
  • –Plaster has greater prospect for being airtight
  • Wet and dry
  • –Plaster parge coats are used before plasterboard

Plasters: Material choices

  • Gypsum: lightweight, insulating, low thermal mass, low hygro-scopicity
  • Cement: tough, high density, acoustic mass, thermal mass, impermeable, water and frost resistant, high carbon & energy
  • Lime: moisture vapour permeable,
  • Clay: natural, hygroscopic, high moisture mass, high density, high thermal mass, absorbs smells, absorbs moisture, absorbs radiation

Airtightness Approach

  • Brown envelops wont achieve 80% reduction
    • Testing comes too late
  • Testing should occur before finishes
    • Test the building fabric
  • But airtightness awareness starts on day one
    • Design it: Specify who fixes it
    • Educate the trades
  • Blower in user throughout the works that affect the external envelop and hollow constructions
  • Every drill or cut: air in your face
    • You made it, you fix it


  • ‘Build tight ventilate right’
  • Open windows in summer
  • Uncontrolled ventilation: loses heat in winter
  • Mechanical ventilation: constant low power during winter <100 watts
  • Heat recovery: efficient is essential >85%
  • Passivhaus accredited MVHR is suitable
  • Whole house
  • Whole house retrofit available too
  • Supply via hall ceiling into rooms
  • Return via hall, WC, bathroom and kitchen

Heating: Radiators

  • Radiators
    • Existing radiators: below windows
      • External Insulation:
        • Add reflective foil panels to wall
        • Or heat up the thermal mass too much
      • Internal Insulation:
        • Radiators come off and pipes move
        • Opportunity to move
        • To internal partitions
        • But if they are well very insulated external walls it may not make much difference

Heating: Under floor or in-wall

  • Under floor heating
  • –Disruptive to install
  • –Opportunity to insulate the ground floor
  • In wall piped heating
  • –Insitu pipes and plaster
  • –Boards with pipes and skim
  • –Less disruptive to install
  • –Internal wall partitions,
  • –Non-domestic: screens, furniture


GBE CPD Case Studies

  • Refurbishment TSB Retrofit for a Future (CPD) N#329

GBE Projects

Flood Zones

  • Contrary to Government Instruction:
    • Don’t build in them
      • Build above them if you have to
  • Contrary to EA advice:
    • Don’t design in sacrificial materials
      • You rely on your insurers
      • You rely on the refurbishment sector
      • The refurbishment sector is busy for 3 or more months doing the neighbours repairs
      • You rely on waste sector & landfill capacity
  • Design to hose down and carry on as normal the day after the flood subsided

Flood risk:

  • Determine potential flood level
  • Site profiles to:
    • redirect water?
    • Defend against water?
      • EA Permitting
  • Raise above water levels
    • Jacking existing buildings up
    • Expensive

Flood risk: Site

  • Existing site boundaries: masonry walls
    • Add to make watertight
    • Removable Covers for gates
  • Bund earth banks: EA Issues
    • Visual barrier
    • Impact down stream
  • Whole building barriers:
    • Floatation or Fold up

Flood Risk: Building

  • Accommodation to upper floors
  • Construction:
    • Avoid hollow systems: dry-lining, timber frame
    • Use solid walls, bricks/blocks, render and skim
    • Avoid timber construction: vulnerable to moisture
  • Materials:
    • Avoid permeable materials: Insulation
    • Water and Frost resistance: important
    • Ability to dry out: permeable assembly
    • Avoid water soluble finishes: clay

Flood Risk: Services:

  • High level electrics above flood level
  • Flood valve to WC
  • Removable Covers for Air bricks
  • Removable Covers for external doors, gates and windows

© GBE GBC GBL NGS ASWS Brian Murphy aka BrianSpecMan **
9th June 2014 – 25th January 2021

Retrofitting SusCon 3 Domestic CPD


SusCon Sustainable Construction

SusCon Sustainable Construction

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GBE CPD Course

GBE CPD Retrofitting SusCon 1to6 PNG

GBE CPD Seminar

Retrofitting SusCon 3 PNG

Retrofitting SusCon 3 PNG

Presenters and organisations

Brian Murphy aka BrianSpecMan BRM @ Build4 CAPEM Showroom

Brian Murphy aka BrianSpecMan BRM @ Build4 CAPEM Showroom

NGS Business Card 2019 PNG

Cath Hassell Team, Water Champion, Carbon Champion,

Cath Hassell Team, Water Champion, Carbon Champion,


  • Show PDF to view
  • Retrofitting SusCon Series 1to6 PDF
  • Show PPTX to present go to GBE Shop

© GBE GBC GBL NGS ASWS Brian Murphy aka BrianSpecMan **
6th June 2014 – 25th January 2021

Retrofitting SusCon 3 Domestic CPD
See Also:

GBE Past Events


GBE Course

CPD Topics

Building Case Studies:



  • See CPD Topic list above

GBE Brainstorm

GBE Briefing



GBE In-House CPD

GBE Lectures

  • Refurbishment is not a hot topic in Architectural Education

GBE Lecture Courses

RIBA Part 2 Post-Graduate

RIBA Part 2 M Arch Lab 1 University of Hertfordshire 2019-2020

GBE Issue Papers

CPD Manufacturer’s

GBE Manufacturer

GBE System

© GBE GBC GBL NGS ASWS Brian Murphy aka BrianSpecMan **
13th November 2015 – 25th January 2021

Retrofitting SusCon 3 Domestic (CPD) G#356 N#357 End

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