ABBE Level 3 Diploma in Domestic Green Deal Advice 6

Report
ABBE Level 3 Diploma in
Domestic Green Deal Advice
6. Building Fabric - Advice
Presented by [Name]
① Insulation Materials
⑥ Solid Wall Insulation
② Loft Insulation
⑦ Draught-Proofing
③ Insulation at Rafters
⑧ Energy-Efficient Windows & Doors
④ Flat Roof Insulation
⑤ Cavity Wall Insulation
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The Measures
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Insulation Materials
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Insulation Materials
Insulation is often the cheapest and most affective solution to heat loss
in the home.
Insulating the building envelope will allow the reduction in the U-values
for the specific building elements:
• Roof
• Walls
• Floor
The energy bills and burden on the occupier will be reduced by not
having to continually renew the heat inside the dwelling, making
insulation an effective way to save energy.
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Types of Insulation Material
There are different types of insulation available to insulate the home.
Common types of insulation are:
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•
•
•
•
•
Air-based
Foam
Foil
Aerogel/ Nano gel
Recycled cellulose
Thermal linings
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Air-Based Insulation
Air-based insulation works primarily by trapping air.
Mineral wool is the most commonly used insulation
of this type:
• e.g. rock wool, stone wool, glass wool, glass fibre
However there is also a range of natural materials that work in the
same way:
• e.g. sheep’s wool, hemp, cellulose
All are available as quilt, batts or blown fibre.
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Air-Based Insulation
Air-based insulation products are available in
rolls of different widths and thicknesses for
quick and simple DIY installation - for
example, between the:
• Rafters in a roof; or
• Joists in a ceiling or floor.
It can also be produced as lightweight 'slabs'
for installing into the cavity walls when
building new houses.
Loose mineral wool can also be used to fill
cavity walls, and is blown in through a hole
drilled in the wall after it is built.
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Cellulose
Cellulose is perhaps the best example of
recycled material use in insulation. Most
cellulose insulation is approximately 80%
post-consumer recycled newspaper by
weight; the rest is comprised of fire retardant
chemicals and, in some products, acrylic
binders.
The biggest long-term performance concern
with cellulose insulation is possible loss of
fire-retardant chemicals. Because borates
are water-soluble, they can leach out if the
insulation gets wet.
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Damp spray cellulose
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Foamed Insulation
The alternative to air-based insulation
materials is foamed insulation. Foamed
insulation can perform significantly better
than air based insulation, but generally has a
higher capital cost.
High performance insulation boards
There are four common types:
• Polystyrene expanded/extruded
• Polyurethane
• Phenolic insulation
• Polyisocyanurate
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Phenolic insulation
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Foamed Insulation
Expanded polystyrene foam (EPS) is
usually white. Some new innovative EPS
products are grey due to the inclusion of
graphite, which substantially increases the
insulation performance. EPS is safe, nontoxic and inert. The most important
properties of EPS are:
•
•
•
•
•
•
Excellent thermal performance & high
compressive strength
Outstanding impact absorption
Low weight
Imperviousness to moisture
100% recyclable
Commonly used as insulation to floors, walls
and roofs. Also used in bead form for loose fill
applications.
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Foamed Insulation
All 4 foam insulation materials are available as rigid foam sheets or as
a spray-on product.
Benefits: Foam insulation provides a number of benefits over other
types of insulating materials. It has a relatively high R-value per inch,
and can insulate effectively in small spaces. It is also easy to cut and
install, and does not produce itchy fibres like those in fiberglass batting.
Foam also tends to hold its shape over time, so fewer gaps form where
air can leak through.
Drawbacks: It is one of the most expensive insulating materials,
especially when compared to fiberglass. It is not fireresistant, and must be covered by drywall to reduce fire
risk.
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Foamed Insulation
Rigid Foam - Uses
• Existing solid wall
• New build cavities
• Ceilings or on top of roof sheathing
• Pitched roofs.
• Footers and foundations (used to keep cold air from reaching
the basement or floor slab)
Spray Foam – Uses
• Loft insulation
• Existing wall cavities (the foam quickly expands to fill the
entire space)
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Spray Foam Insulation
Polyurethane insulation is also available as ‘spray foam’.
This is most commonly encountered as insulation for hot water cylinders
but may also be used to insulate walls or roofs.
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Multi-Foil Insulation
Multiple low emissivity surfaces separated by
foam. To be effective, the outer layers must
face an unventilated cavity.
Performance achieved is controversial –
generally recommended to be used with
conventional insulation.
Local Authority Building Control guidance
indicates that a maximum resistance of 1.7
m2K/W should be used in U-value
calculations for this.
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Multi foil insulation
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Thermal Linings
Thermal Linings are a thin material specifically
developed for energy conservation up to 10mm.
It is a remarkable material which, when applied
inside the property on external walls, reduces
heat loss resulting in warmer rooms. Thermal
Linings:
• Can be used in all residential properties flats, houses, bungalows and mobile homes
• Can be applied inside the property on
external walls and ceilings
• Provides a warm surface to combat
condensation
• Provides sound insulation as well as
outstanding thermal properties
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Aerogel
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Insulation Materials
This table shows the thickness of
each material that is required in
order for them to achieve the
same U value of 0.2W/m2 .
Illustration courtesy of the Architects Journal
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Loft Insulation - Advice
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Loft Insulation
Loft Insulation increase
0 to 270mm
Loft insulation increase
100 to 270mm
Savings per annum
Up to £180
£30
Installation cost
£100 to £350
£100 to £350
Pay back time
Up to two years
From four years
C02 per annum
720kg
110kg
Heat rises, and in an un-insulated home a quarter of heat is lost through the roof.
Insulating the loft, attic or flat roof is a simple and effective way to save waste and
reduce heating bills.
Loft insulation is effective for at least 42 years, and it will pay for itself over and over
again in that time.
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Installation
Installer Requirements/DIY Practicalities
Loft insulation is a excellent EEM if it can be effectively installed, but
there are several issues to be considered, if the installer is to maximise
the benefits of the installation for the customer. These include:
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•
•
•
•
•
Loft access
Loft condition
Infestation
Avoiding fire hazards
What is in the loft
Using the loft as storage after the installation
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Installer Requirements: Loft Access
Hatch size
• On the rare occasions where the loft hatch is not big enough to get the insulation into
the loft, a new loft hatch can be created at an additional cost by a professional
installer.
Hatch in a dangerous location
• There will be times when the loft hatch is in a place that is unsafe for the GDA to
access; this may not be the same for the installer who will have specialist equipment
and appropriate safety equipment to be able to complete the job on most occasions.
• The GDI must also comply with relevant heath and safety legislations,
e.g.
•
The Work at Height Regulations 2005 (as amended)
•
Safe use of ladders and stepladders - An employers’ guide
The DIYer must be competent to undertake the job and be aware of all of the
potential risks involved.
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Installer Requirements: Condensation
Condensation accumulates when humid air
makes its way into the loft and condenses on
the underside of a cold roof.
The problem can be so bad that in many
cases, it is assumed that a leaking roof has
caused the problem.
Condensation can saturate roof timbers, give
rise to mould and fungus growth, and
compromise the roof structure, and – in
extreme cases – soak into loft insulation
reducing its effectiveness and causing water
stains on the underside of the ceiling.
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Condensation
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Installer Requirements: Ventilation
A ventilation path of at least 25mm in width is required between the insulation and the
underside of the sarking.
Holes and gaps in the ceiling should be sealed to restrict the amount of moist air entering
the roof space.
For roofs over 35o pitch, or over 10m span, ridge ventilation is required equivalent to a
continuous 5mm gap.
The traditional ‘cold roof’ or ‘loft’, found in the vast majority of existing buildings, handles
moist air from inside the building by allowing it to diffuse through the ceiling into the roof
void from where it is removed through cross ventilation.
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Installer Requirements: Condensation
The latest Building Regulations summarises best
building practice as "build tight, ventilate right".
This refers to ensuring that all openings to the outside of the building
are closed up to ensure heat conservation, whilst providing ventilation
is present at points of moisture production, such as bathrooms kitchens
and lofts
Insulation stops heat escaping from living spaces, making the loft
colder - which could make existing damp or condensation problems
worse. You should seek professional advice before installing insulation,
to find the best solution to the damp problems first.
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Ventilation: Common Issues
Common ventilation issues that the installer should consider
include:
• Blocking of existing ventilation due to insulation being pushed into
the eaves, preventing air flow.
• Inadequate ventilation due to under-ventilation after insulation is
topped up/installed.
• Loft storage blocking the flow of air to parts of the loft, preventing air
circulation.
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Installer Requirements: Infestation
Scurrying and scraping noises from the attic are also a strong indication
that rodents or other wildlife have taken up residence in the roof space.
The first step is to inspect the attic and look for visible signs of
habitation, the most common of which are droppings.
The most common infestations are:
• Mouse/Rat
• Squirrel
• Bird
• Insect
• Bat
All these infestations will have to be resolved before an installation
takes place; a specialist pest control company would be best placed to
deal with the issues.
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Infestation: Bats
Bats are protected as an endangered species in
this country, and it is an offence to try to kill or
remove bats or to change or block their roosts.
Even if bats have left the attic, it is still an
offence to block the roost: bats return to the
same place every year and so even empty bat
roosts are protected.
If a homeowner is aware that bats are in their
attic, they should consult with the Bat
Conservation Trust before carrying out insulation,
remedial timber treatments, insect control or
rodent control that may cause harm to bats.
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Infestation: Bees
Protected Species are as designated by the
Wildlife and Countryside Act 1981 and in the
case of insects by Schedule 5 of the Act.
Neither honey bees, bumble bees or any
other species of bee is included as a
protected species or offered any
protection as a protected species.
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What’s in the Loft?
In many lofts there are obstacles which will need addressing before an
effective installation can take place, such as:
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•
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•
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Storage
Boarding
Water tank
Pipes
Cables
Spot lights
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Storage/Boarding
Insulation depth
Thermal resistance
270mm
6.11m2 k/W
100mm
3.09m2 k/W
Compressing insulation after it has been fitted will degrade its thermal
efficiency, by up to 50% and increase payback times, as a large part of
its insulant value comes from the air trapped within the fibres.
However, it is possible to arrange for joists to be extended and floor
boarding to be fixed to help maintain the storage area.
If you already have a boarded area of no more than a third of the loft
area the installers will work around it and leave it uncovered.
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Pipes/Tank
Any company who carries out loft insulation is responsible for insulating
any tanks and pipework that are in the roof space to ensure they do not
freeze during the winter.
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Cables
A cable that feeds a shower unit is usually a 30amp. The installers will
identify this and make sure this cable is not covered by the insulation,
by either laying the cable on top if there is enough flex, or leaving a gap
in the insulation around the cable to ensure it does not overheat.
Other cables in the loft tend to be lighting cables, which are less
affected by the insulation derating them.
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Recessed Lights
The installers will cut the insulation away from recessed lights, leaving
a gap of approximately 2” around the lights to prevent overheating.
Alternatively,
An Intumescent Downlight Cover can be fitted.
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Existing Loft Insulation
Existing insulation can be left in the loft and an additional layer added
to it to bring it up to the required minimum thickness.
It does not matter how long the existing insulation has been in the loft; it
still retains its insulant value, providing it has not been compromised.
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Loft Insulation: Cost
Rockwool vs. Sprayfoam for lofts
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Loft Insulation: Summary
There are four basic types of insulation used in insulating lofts:
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•
•
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Air based
Loose fill
Blown insulation
Ridged board
Air Based will be used for the default
calculation in the Occupancy Assessment
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Insulation at Rafters - Advice
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Insulation to Sloping Ceilings
Where there are rooms in the roof, insulation can be added to the
sloping ceiling areas either:
• Between the rafters; and/or
• Above or below the rafters.
The best option depends on what other work is required to the roof (if
any).
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Insulation to Sloping Ceilings
Insulation between the rafters is the most straightforward to install, and
avoids any loss of room height.
(Diagram shows a section through
the sloping ceiling looking up or
down the slope)
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Ventilation space limits insulation
thickness – air gap must be at
least 50mm
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Insulation to Sloping Ceilings
Breathable
sarking
membrane
Ventilation space can be reduced but not eliminated if a breathable
membrane is present.
Alternatively, an additional set of battens can be fitted along the top of
the rafters so that the insulation thickness can equal the rafter depth.
(The diagram shows a section through the sloping ceiling looking up or
down the slope.)
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Insulation to Sloping Ceilings
Due to:
• The need to maintain the ventilation space
• The cold bridging effect of the rafters; and
• The fact that the rafters are rarely more than 100mm deep
It is usually necessary to add an additional layer of insulation above or
below the rafters to achieve a reasonable target U-value.
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Insulation to Sloping Ceilings
Sarking Insulation
If insulation is added above the rafters, it is sometimes known as
‘sarking insulation’.
(Diagram shows a section through the sloping ceiling looking up or
down the slope.)
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Room in Roof Issues
If a ‘Room in Roof’ (RIR) is not heated from the fixed heating, the DEA
software will assume portables (which will be more expensive).
Ventilation will need to be maintained in a residual area when insulation
is topped up; cross flow ventilation may need to be installed.
Insulation in RIR may not be appropriate even if the software has
specified it, for example due to access issues.
Stud walls within the RIR the stud walls will need to be insulated to the
required standards 0.25w/m2k for all elements, around about 210mm
with mineral wool or 100mm with foil faced foam insulation.
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RIRs not identified in RdSAP
If the RIR has been identified as being outside the RdSAP
methodology, e.g. no staircase:
• The software will underestimate the heating needs for the
property.
• The software may also make an inappropriate insulation
recommendation.
These issues will put finance for the unidentified RIR beyond the scope
of GD funding.
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Flat Roof Insulation - Advice
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Flat Roof Insulation
Flat roof insulation is often done when the roof covering is being
replaced. Insulation may be installed above or below the existing
“deck”.
• A “cold roof” or “cold deck” has the insulation below the existing
“deck”.
• A “warm roof” or “warm deck” has the insulation above the existing
“deck”.
• An “inverted roof” has the insulation installed above the
waterproof covering.
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Cold Roof (or Cold Deck)
Alternatively insulation can be installed between the joists, although this
is less effective due to the cold bridging due to the joists.
A ventilated air space of at least 50mm should be retained above the
insulation waterproof.
Waterproof covering on
roof deck
Insulation between joists
Plasterboard
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Cold Roof (or Cold Deck)
If the reduction in room height is not a problem, insulation can be
installed below the roof joists.
The air space between the joists should be cross-ventilated to avoid
any risk of condensation.
Waterproof covering
on roof deck
Joists
Insulation
Plasterboard
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Warm Roof (or Warm Deck)
In a warm roof, the insulation is installed above the roof deck but below
the waterproof covering.
This is usually considered to be the best option as it eliminates any risk
of condensation but is only cost effective when the roof covering is
being replaced.
Waterproof covering
Insulation
Joists
Plasterboard
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Inverted Roof (or Inverted Warm Deck)
In this case the insulation is installed above the waterproof covering,
avoiding the need to disturb the existing roof structure.
It may also prolong the life of the waterproof covering.
However, rainwater penetration may reduce the thermal performance of
the insulation.
Gravel or other ballast
Insulation
Waterproof covering
Joists
Plasterboard
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Insulation to Flat Roofs
Measure
Annual Saving
Installation
Cost
CO2 saving per Pay Back Time
year
Flat roof
£180
£3500
800kg
19 years
Installing flat roof insulation could save you around £180 and 800kg of
carbon dioxide a year
If half your roof area is flat - the savings will vary depending on how
much of the property has a flat roof.
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Cavity Wall Insulation - Advice
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Cavity Wall Insulation
If a house was built after 1920, the chances are that its external walls
are made of two layers with a gap or cavity between them.
Cavity wall insulation fills that gap, keeping the warmth in to save
energy. It can also help reduce condensation inside the house if this is
a problem.
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Cavity Wall Insulation
Houses with cavity wall insulation have the following benefits:
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•
•
•
•
Reduced fuel bills.
A warmer house that stays warmer longer.
Reduced condensation.
Fewer draughts.
Benefits to the environment.
Cavity wall insulation can reduce the heat loss through cavity walls by
up to 40 per cent. It can also lead to reduced heating costs and
improved comfort levels.
Payback (savings against costs) times are estimated at
2 to 3 years.
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Cavity Wall Insulation
Cavity Wall Insulation is a simple process by which insulation is injected into this cavity
through a carefully designed pattern of holes.
There are a number of different products, or systems, each of which must pass stringent
technical requirements laid down by the British Board of Agrement (BBA) or alternative
independent approvals body
All systems are "fit and forget" and require no servicing, maintenance or
adjustment.
Cavity Insulation Guarantee Agency CIGA has registered installers, and offers
Guarantees for, all 3 products for 25 years.
•
•
•
Mineral wool
Polystyrene bead
Foam
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Cavity Wall Insulation: Materials
Mineral Wool
Mineral Wool insulation is a cotton wool like material produced from either rock wool or
glass wool, and is used in the majority of installations.
Polystyrene Bead
Bead is made up of small expanded polystyrene beads normally injected with a binder.
Foam
Urea Formaldehyde cavity wall insulation was introduced into the UK in the late 1960's
and involves the injection of a water based chemicals system that produces an insulating
foam in the cavity.
Polyurethane foam is now used as both a cavity insulation material and wall stabilisation
material where the wall ties have failed, as an alternative to wall tie replacement.
However, where work is carried out purely for thermal insulation purposes either mineral
wool or polystyrene beads would normally be used.
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Installer requirements
Is the House Suitable for Cavity Wall Insulation
Before the installation, the installing firm will undertake an assessment of your property to
confirm that it is suitable for insulation. This assessment may be undertaken by a
surveyor or the Technician before installation using a boroscope.
How long does it take
Cavity wall insulation normally takes around two hours to install, but the time does
depend on the size of the house and other factors, such as access.
What about filling the holes
All the holes through which the insulation is injected are filled with mortar to match the
existing colour and texture as closely as possible. On pebbledash finishes, pebbles are
added to the surface to match the existing finish. After weathering, the holes are difficult
to see.
Access
Site access will also be needed for the installer equipment usually they will need
to be able to park a lorry. Scaffolding may be required to access difficult to reach
areas around the property, over extensions, conservatories, garages etc.
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Potential Savings
Measure
Annual
Savings
Insulation
Costs
Payback Time Co2 per year
Cavity wall
insulation
£150
£500 - £1000
Less than 5
years
Around 550kg
These are estimated figures based on insulating a gas-heated, semidetached home with three bedrooms.
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Cavity wall insulation
6 million homes in Britain have now had cavity wall insulation installed,
it's the smart way to save money.
The Government regards cavity wall insulation as one of the most
effective energy savings measures that people can carry out on their homes
and apart from saving money it's a major contributor to reducing emissions
External walls account for 35% of heat loss from the average house, and
studies suggest that every square metre of Cavity Wall Insulation will save
more than a tonne of Carbon Dioxide over the average life of the building. For a
semi detached house with an external wall area of 80m2, this equates to
savings of 80 tonnes or more.
The insulation present in a filled cavity reduces this heat loss,
making the house warmer or reducing the amount of fuel
required to maintain a comfortable temperature.
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Reasons Not to Install
Issues that might impact on installation
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•
•
•
•
•
•
•
•
Rain penetration/severe exposure
Access issues
Narrow cavities
Blocked cavities
First floor properties
Partially filled cavities
Poor pointing/cracked render
Cladding or render
Cost
How are they dealt with?
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Reasons Not to Install
Air bricks and flues
Air bricks maintain ventilation to the under floor area, lofts, kitchens and
bathrooms. To prevent condensation and reduce damp within the
property.
Properties with a cavity built before 1995 may not have had a cavity
sleeve fitted; this can be addressed by the installer so the insulation
material does not block the flow of air. Care should be taken to avoid
cold bridging.
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Reasons to not install - CW
Often 1983-1995 dated properties will not have had any cavity wall
insulation, due to the specifications of the time being more concerned with
the thermal comfort of the property:
•
e.g. the builder wouldn’t install cavity insulation, but to comply
with thermal comfort regs would install an up-rated heating
system;
However, the software will assume there is insulation and not recommend
it.
You would need to inform the customer that the EPC would not make the
recommendation and that they would need to seek specialist advice to
ascertain whether or not CWI is present.
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Solid Wall Insulation - Advice
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External Wall Insulation
To insulate a solid wall from the outside, a layer of insulation
material is fixed to the walls with mechanical fixings and adhesive,
then covered with protective layers of render or cladding.
The finish can be smooth, textured or painted, tiled, panelled, pebbledashed (for easy maintenance) or finished with brick slips to provide a
real masonry brick finish.
The finish will cover the whole of the outside of the property, including
existing brickwork, and may change its appearance. Therefore,
planning permission may be required.
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External Wall Insulation
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External Wall Insulation
Insulating the outside of a property will:
•
•
•
•
Provide a new weather-proof layer
Protect the property from penetrating damp
Increase the temperature of the internal surface of the wall
Reduce condensation problems on internal walls
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External wall insulation
External wall insulation is most cost effective when re-rendering, or
other measures to prevent rainwater penetration, are required.
Any other repairs needed to the walls should be carried out first.
There are two common methods:
• Wet render systems
• Dry-cladding
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External Wall Insulation: Dry-Cladding
Cladding comes in a variety of attractive
colours and forms: timber panels or shingles,
stone or clay tiles, aluminium panels or a
brick finish.
In these systems insulation is also fixed
directly to the existing wall but instead of
render, a range of alternative ‘dry’ cladding
materials can be used, e.g.
•
•
•
•
Timber
Ceramic or clay tiles
Brick slips
Metal panels
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External Wall Insulation: Wet Render
Render can be either a thick sand and cement
mix applied over a wire mesh, or a thinner,
lighter cement over a strong fibre mesh. It is
generally less expensive than cladding.
In these systems, insulation batts or boards are
fixed to the existing external wall, covered by a
wire mesh and then an outer coating of
sand/cement render to provide a waterproof
finish.
Rendering
Most commonly the render is painted, but a
‘pebbledash’ finish can be used to reduce
maintenance costs and/or improve the
appearance.
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Eternal Wall Insulation
All external pipework and other fittings will have to be
removed and replaced, and it may be necessary to extend
electric boxes, window sills and even the roof
overhang(soffit) to protrude beyond the new layer. It is often
possible to fit additional sills to avoid replacing any of the
original structure.
To prevent condensation, recessed areas around windows must
be insulated as well as the walls – with the depth of insulation
depending on the width of the window frame.
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External Wall Insulation
Benefits
• Can be applied without disruption to the household inside.
• Does not reduce the floor area of the home.
• Renews the appearance of outer walls.
• Improves weatherproofing and sound resistance.
• Fills cracks and gaps in the brickwork, which will reduce draughts.
• Increases the life of walls by protecting the brickwork.
• Reduces condensation on internal walls and can help prevent damp
(but will not solve rising or penetration damp).
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External Wall Insulation
Restrictions
• Is not recommended if the outer walls are
structurally unsound and cannot be
repaired.
• Best installed at the same time as
external refurbishment work to reduce the
cost.
• May need planning permission.
• Requires good access to the outer walls.
• Lots of older houses have an attractive frontage
which wouldn't be suitable for external insulation, but
a much less impressive rear where external
insulation could be just the thing. The front wall can
then be insulated internally, one room at a time.
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Internal Wall Insulation
Internal wall insulation is sometimes referred to as ‘dry-lining’, but
technically dry-lining might only consist of plasterboard with an airspace
behind it, i.e. not necessarily including any insulation material.
There are two ways to insulate a solid wall internally:
• Rigid insulation boards
or
• Insulated stud wall
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Internal Wall Insulation
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Internal wall insulation
Rigid insulation boards
Plasterboard backed with rigid insulation is fitted to the inside of
your walls. The insulation is usually made from one of several forms of
foamed plastic. It should normally be at least 60mm thick, and can be
up to 100mmm. The actual thickness required will depend on the
material used.
Insulation boards are fixed straight onto the wall using continuous
ribbons of plaster or adhesive. Extra fixings hold the boards firm, and
joints between boards are sealed to prevent air leaking out.
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Internal wall insulation
Stud wall
A metal or wooden studwork frame is attached to the wall and
filled in with mineral wool fibre. It can then be plastered over,
ready for redecoration.
Mineral wool insulation is less effective than rigid insulation boards, so
the filling needs to be at least 120mm thick.
Instead of applying plaster, the frame can be covered with rigid
insulation boards for even more effective insulation, reducing your
running costs even further.
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Internal Wall Insulation
A
Dot and dab
(no insulation)
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B
Stud wall
(Insulation in
between studs)
C
Ridged Board
(insulation
backed board)
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Internal Wall Insulation
Disruption for internal insulation
External walls will need to be removed and reattached, so that they are flush with your
new ‘wall’. So will features such as:
• Light fittings
• Radiators
• Pipe work
• Skirting boards
• Door frames
• Coving
• Cornices
Areas around windows must be insulated at the same time as the walls, to prevent
condensation.
It is therefore also easier if the property is unoccupied, although one room
could be done at a time.
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Internal Wall Insulation
Benefits
•
•
•
•
•
•
is generally cheaper to install than external wall insulation
will slightly reduce the floor area of any rooms in which it is
applied (the thickness of the insulation is around 100mm)
is disruptive, but can be done room by room
requires skirting boards, door frames and external fittings to
be removed and reattached
can make it hard to fix heavy items to inside walls – although
special fixings are available
needs any problems with penetrating or rising damp to be
fixed first.
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Internal Wall Insulation
Flexible thermal linings
These are typically 10mm thick and applied like wallpaper
They are not thick enough to meet the standards of Part L1B but
they can be useful to:
•
reduce the effect of thermal bridges, e.g. on window reveals
•
in cold corners where condensation occurs
•
where space is limited, e.g. around dormers
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Hybrid insulation
Hybrid systems are combination of both external and
internal wall insulation installed on the same property.
Care must be taken during installation to reduce cold bridging an
overlap of the two insulation methods (internal & external) must be
achieved to minimise the effect so condensation patches are not
created.
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Damp and Condensation
Insulating walls internally will make the inside surface of the wall
warmer, making it less likely that moisture in the air will condense
on the wall.
If a property currently has condensation problems then internal wall
insulation could help reduce the problem.
It is difficult to insulate every square centimetre of the house, and there
are almost bound to be some areas that remain cold - for example,
where an internal wall meets an external wall. There is then a risk of
condensation collecting in these areas and perhaps going unnoticed
until a problem develops. This problem can generally be minimised by
insulating carefully around window recesses, doors and the edges of
internal walls.
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Damp and Condensation
If insulation is incorrectly fitted, there is also a risk that moisture will migrate from
the warm air in the room through the insulation until it meets the cold solid wall
(interstitial condensation)..
It can then condense inside the wall structure and cause problems. This issue can
be avoided by adding a vapour control layer on the inner surface of the insulation
and ensuring that any breaks in this layer are carefully sealed.
And as with all wall insulation, it is important to make sure that any existing problems of
rising damp or penetrating damp are fixed before insulating, otherwise there is a risk of
the problem getting worse over time as the moisture gets trapped within the structure.
For all these reasons, internal wall insulation must be fitted by an experienced
professional who can ensure that any existing damp issues are resolved and no new
ones are created.
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Regulations
If you insulate a solid wall, you have to make sure it complies
with the current Building Regulations.
•
insulated wall - if you live in England or Wales then it must
have a U-value of no more than 0.30 W/m2K.
as a rough guide you will need around 60mm to 120mm of
insulation to achieve this, depending on what insulation material
you use.
If you are planning to remove and replace more than half of the
internal plaster or external render of a wall, or if you are dry
lining a wall, then you must insulate to this standard whether
you were planning to insulate or not.
This is a consequential improvement.
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Costs
Type of
insulation
Saving per
Year
Cost
Co2 per year
Internal
£445
£5500 - £8500
1.8 tonnes
External
£475
£9400 - -£13000
1.9 tonnes
Values based on a 3 bedroom house
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Keeping the Costs Down
Internal insulation can be installed at the same time as other works – for
example when a new kitchen or bathroom is fitted, or when rooms are
redecorated.
External insulation can also be combined with other works. For example if
scaffolding is already erected – perhaps as a new roof is being fitted, or
windows are being redecorated, or solar PV panels are being fitted – then
choosing to fit the insulation then could save a bit on the costs. And if rendered
walls have damaged render, or brick walls need re-pointing, external insulation
may not cost much more than the cost of basic repairs.
Lots of older houses have an attractive frontage which wouldn't be
suitable for external insulation, but a much less impressive rear where
external insulation could be just the thing. The front wall can then be insulated
internally, one room at a time.
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Floor Insulation - Advice
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Ground Floor Insulation
Ground Floor Insulation
Insulation to ground floors has been required by the Building
Regulations in new homes since 1996.
(This applies to England and Wales –1992 for Scotland and Northern
Ireland.)
Floors to be considered:
• Ground floors
• Exposed floors
• Floors over unheated space
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Suspended Timber Ground Floors
Sometimes there is access below a
suspended timber floor, e.g. from a cellar.
In these cases insulation can be installed
between the joists. This is a simple process
(and could be done by a DIY enthusiast).
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Ground Floor Insulation
One way of doing this is to insert insulation quilt between the floor joists
and hold it in place with netting stapled to the joists.
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Ground Floor Insulation
Alternatively you can use rigid insulation boards and hold these against
the underside of the floor boards with battens nailed to the side of the
joists.
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Floor Insulation
If there is no space to access a timber floor from below, insulation
can only be added by taking up the floor boards.
The same methods as described above can then be used.
This is usually only cost effective if the floor boards need to be taken up
or replaced for another reason, e.g. as part of a full refurbishment
project.
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Floor Insulation
The simplest way of improving the thermal performance of an existing
concrete ground floor is to add insulation and a new floor deck on top of
the existing floor.
Though simple, raising the floor level through added insulation will
usually require:
•
•
Skirting's
Radiators
To be removed and re-fixed and doors to be
increased in height
Ensure that any remedial work is undertaken on the slab ahead of
installing the insulation.
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Ground Floor Insulation
An existing concrete floor can only easily be insulated by adding
insulation and new flooring on top of it.
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Ground Floor Insulation
Concrete ground floors
If a concrete floor needs to be replaced for any reason, the new floor
should be insulated. The insulation can be above or below the concrete
slab –insulation below the slab has the advantage of including thermal
mass.
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Ground Floor Insulation
Retrofitting insulation to the ground floors of homes is rarely considered due to:
•
•
Relatively low heat loss from ground floors compared to external
walls or roofs, due to the insulating effect (Thermal Mass ) of the
ground.
The cost and practical difficulties of installing ground floor
insulation in most cases.
Where insulation is specified, ensure that it does not come into contact with
cabling.
A fire-resistant board should be used beneath the joists if the floor is above a
garage or basement.
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Draught-proofing - Advice
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Where to look for draughts
Draughts happen where there are unwanted gaps in the construction of
your home, and where openings are left uncovered.
You’ll find draughts at any accidental gap in your home that leads
outside, such as:
•windows
•doors – including keyholes and letterboxes
•loft hatches
•electrical fittings on walls and ceilings
•suspended floorboards
•pipework leading outside
•ceiling-to-wall joints.
You should block most of these but be careful in areas that need good ventilation:
•areas where there are open fires or open flues
•rooms where a lot of moisture is produced, such as the kitchens,
bathrooms and utility rooms.
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Draught-proofing
Draught proofing is a cheap and efficient method of saving both
energy and money.
Draughts are similar to ventilation in that they supply the home with
fresh air. However, draughts are uncontrolled and can let in too much
cold air as well as allowing heat to escape. Draught proofing blocks up
any unwanted gaps that let cold air in.
Types of draught proofing can include:
• Self-adhesive sealant strips
• Brushes
• Spray foams (sprayed into gaps around windows)
• Sealants
• Weather strips (door and window reveals)
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Examples of Draught proofing
Examples of draught proofing include that can be
financed through Green Deal.
• Windows
• Doors
• Loft hatch insulation (loft insulation)
Examples of draught proofing include that also
can be financed through Green Deal.
•
•
•
•
Brushes
Sealants
Adhesive sealant strips
Spray foams
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Draught proofing
How much could you save by draught-proofing?
Full draught-proofing will save you on average £55 per year. Draughtfree homes are comfortable at lower temperatures – so you’ll be able to
turn down your thermostat. This could save you even more
Generally draught proofing is a measure that can be
considered for most Dwellings
Part F (Ventilation)
Approved Document F of Schedule 1 of the Building Regulations covers the
requirements in respect of ventilation.
The Domestic Ventilation Compliance Guide contains the principal guidance for air
bricks for open flued appliances, trickle vents, etc…
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Energy-Efficient Glazing and
Doors - advice
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Energy-Efficient Glazing
All properties lose heat through their windows, but energy-efficient
glazing reduces this. That might mean double or triple glazing, or
secondary glazing.
Energy-efficient windows come in a range of frame materials and styles. They
also vary, depending on:
•
•
•
How well they stop heat from passing through the window.
How much sunlight travels through the glass.
How little air can leak in or out around the window.
If a property does not have 100% energy-efficient windows, think about
upgrading.
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Energy-Efficient Glazing
Advice
Glass: The most energy-efficient glass for double glazing is low emissivity (Low-E)
glass. This often has an unnoticeable coating of metal oxide, normally on one of the
internal panes next to the gap. This lets in light and heat but cuts the amount of heat
that can get out.
In between: Very efficient windows might use gases such as argon, xenon or krypton
in the gap between the sheets of glass.
Pane spacers: These are set around the inside edges to keep the two panes of glass
apart. For maximum efficiency, look for pane spacers containing little or no metal –
often known as ‘warm edge’ spacers
Measure
Savings
Cost
C02 per annum
Double Glazing
£180
3000 - 6500
680kg
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Energy-Efficient Glazing: Benefits
• Smaller energy bills: replacing all single-glazed windows with Brated double glazing could save around £170 per year.
• Reduced emissions: by using less fuel, a property will generate
less of the carbon dioxide that leads to global warming - typically,
680kg a year.
• A more comfortable home: energy-efficient glazing reduces heat
loss through windows and means fewer draughts and cold spots.
• Peace and quiet: as well as keeping the heat in, energy efficientwindows insulate the property against outside noise.
• Reduced condensation: energy-efficient glazing reduces
condensation build-up on the inside of windows.
The costs and savings for energy-efficient glazing will be different for
each home and each window, depending on the size, material and
installer. Double glazing should last for 20 years or more.
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Energy-Efficient Glazing
Secondary glazing
A secondary pane of glass and frame can be fitted
inside the existing window reveal. This won’t be
as well sealed as a double-glazing unit, but will be
much cheaper to fit, and will still save energy you could save about £100 a year on fuel bills.
Low emissivity glass will improve the performance
of secondary glazing.
Secondary glazing cuts down on costs and is a
non-intrusive way of insulating your windows.
It should be considered in Conservation Areas or
on listed buildings when there are regulations in
place restricting the change of a building’s
appearance.
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It is the best of what can be
achieved under the current
regulations
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Insulated Doors
Under the legislation, all new doors sold and fitted in England and Wales must have a U-value
of 1.8W/m2K (1.6W/m2K in Scotland) or less. The door’s U-value is a measure of its energy
efficiency, and the lower the U-value, the more energy efficient the door.
Features like:
• Keyhole cover
• Letterbox brush
• Weather and draft excluder strips
• A frame fit door
• Professionally fitted
Will all increase the door’s energy efficiency.
Doors can now be tested like windows for there energy efficiency and a simple A-G rating can
be applied to individual products. All Green Deal products, including insulating doors, will have
to be tested and must pass minimum standards to be used by approved Green Deal installers.
Installing insulated doors could save you £30 a year
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Conservatory's
Even the best-quality glazing loses heat more quickly than an insulated
cavity wall. This means that conservatories are not thermally efficient.
Provided they are never heated, and the doors between the
conservatory and the heated house are kept shut in cold weather, they
can actually reduce heat loss by acting as an extra insulating layer on
the outside your house. You can make the most of this by installing a
sealed sliding door,
If you heat your conservatory, any benefit you may have had will soon
disappear along with the heat that escapes into the outside air in winter.
Double glazing, blinds and shutters can all reduce the amount of heat
wasted, but it is not possible to bring a conservatory up to the thermal
standard of even an averagely insulated room. If you want to save
energy and money, save your conservatory for the summer.
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Questions?
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Web Links
www.stroma.com/certification
Contacts
Stroma Certification Ltd.
4 Pioneer Way, Castleford, WF10 5QU
0845 621 11 11
[email protected]
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