To BuilD Back - Have Your Say

Your chance…
to Build Back
Many houses in Canterbury have been
damaged by earthquakes. Recovering from
this damage presents a unique opportunity
to make homes better for you, better for the
environment and cheaper to run.
Repairing earthquake damage is the ideal time to consider
improving your home and the benefits it can bring:
A warmer, drier, more comfortable home
Reduced energy bills and less water use
Improved health with fewer visits to the doctor
A more resilient and valuable home
The purpose of this guide is to help you when talking with
builders and in making decisions about repairing your
home. It provides tips for repairing your home and gives
indicative costs and savings that could be made for an
average sized, three to four bedroom home.
Before you do anything...
Make sure that you have made a claim with the Earthquake
Commission and that your house has been assessed (www., 0800 326 243). Once you have a better idea of
the type of repairs needed, do some further research and
make a checklist of the improvements specific to your home
so that you can discuss them with the relevant insurer,
builder, and tradespeople.
In most cases you, as the homeowner, will have to fund the
additional cost of the improvements set out in this guide.
The good news is that government grants are available for
insulation, clean heating, solar and heat pump hot water,
and chimney replacement. Plus, best of all, you can enjoy
the benefits of these improvements.
Where to start
Use the list below to decide where to start and in what order
to undertake home improvements
1. Thermal envelope. First, stop draughts around windows
and doors, insulate the ceiling and under the floor,
and install thermal curtains; then insulate south walls,
double glaze south windows, and finally, the rest of the
walls and windows.
2. Dampness control. First, check and maintain rainwater
drainage and wastewater pipes; then install a ground
vapour barrier, bathroom ventilation, and kitchen
ventilation; and finally install a vapour barrier in the
walls along with wall insulation.
3. Efficient sustainable heat source. Make the most of
warmth from the sun; then choose efficient heating
systems for living spaces (heat to a minimum of 18°C
when occupied); then bedrooms (heat to a minimum of
16°C when occupied).
4. Water efficiency. Choose the easy and simple measures
first, such as water saving devices placed in existing
toilet cisterns, low flow showerheads, and the purchase
of water efficient appliances; then install aerated taps
and dual flush toilets.
5. Efficient sustainable water heating. First, insulate pipes
with lagging and wrap hot water cylinders; or if thinking
about replacement, consider solar or heat pump hot
water systems.
6. Supplementary water supply. Rainwater tanks for
watering gardens and flushing toilets; consider greywater
systems in areas with well-draining soils.
Heating and Chimneys
Fallen or damaged chimney or fireplace
Replace your old heating system with a new, efficient and clean one.
Remove or repair damaged chimney and consider more efficient alternative
heating options such as heat pump or low emission wood or pellet burner.
Block or remove open fireplaces. If retaining chimney for aesthetic or heritage
purposes, an inset wood or pellet burner with a central flue up the chimney can
assist structurally but you may also need to have it strengthened in case
of future earthquakes - see EQC flyer, Easy Ways to Quake Safe Your Home.
Build Back Smarter...
Cost estimate:
Varies depending on situation, level of damage, and option chosen.
Chimney removal between $500 - $1,000.
Heat pump of an average size would have an installed cost of approximately
»» Low emission wood burner or wood pellet burner between $3,000 – $4,000.
»» Subsidies of up to $500 or more are available from EECA to support the
installation of clean heating devices, provided the house is well insulated.
Further subsidies are available to replace chimneys.
Keeping your home warm (18°C in living rooms and 16°C in bedrooms as
minimums) is vital to your health and comfort, so proper insulation and an
efficient heating system are a must. The typical New Zealand home uses about
35% of its energy on heating – so getting it right can save you money. Putting in
an efficient system can save an average household up to $500 per year compared
to standard electric heating.
Household running cost savings
Improved comfort and better health
Increased capital value of the home
Improved Homestar™ rating
Improved Homestar™ rating
Talk to your builder about…
»» Ways to move the heat around the house – if you are having work done
up in the ceiling, this could be a good time to think about installing a
simple ducted heat transfer system to move heat from the living room to
the bedrooms. They should be between $300 and $1,000 depending on the
number of rooms you wish to connect.
»» Making sure you have good insulation in the house to trap in the heat.
Next steps:
1. Discuss options about removing the chimney and blocking off any
open fires.
2. Investigate the potential for grants / loans assistance from EECA.
3. Investigate suitable heating systems with suppliers.
4. Seek advice from a heating specialist (e.g. your local Eco Design Advisor).
Talk to your builder, plumber or hot water specialist about…
»» Your house set-up, the overall site and the best options for heating
water. How much sun lands on your roof? Is there a suitable place for
a heat pump hot water cylinder?
»» Ensuring that the system you are considering is designed to work
at low temperatures. Ask to see performance results to make sure it
works efficiently in the Christchurch climate.
»» Ensuring location of outside unit for heat pump water heaters is
suitable. Consider efficiency (the warmer spot the better), as well as
the potential noise of the unit (away from bedrooms and neighbours).
»» installing high pressure water systems to eliminate the need for
header tanks which are susceptible to falling or damaging the
building during an earthquake.
Next steps:
1. Check out EECA’s solar and heat pump hot water grant information to
see if you qualify.
2. Discuss options with your builder or hot water specialist – assessing
the whole house and site for the best approach.
3. Make sure that your installer is well qualified and has a lot of
experience - research shows that the quality of installation is the
biggest factor in how well your system will perform.
Broken or poorly fitting windows and joinery
Replace damaged windows with more efficient double-glazing or ‘low-e glass’
options; consider reducing window size on the southern and western sides of
the house.
If your frames are undamaged and only the glass is broken, install double
glazed inserts or high performance ‘low-e glass’ into your existing window
frames. The ‘e’ stands for ‘emissivity’, which means that it lets light in but stops
heat escaping as quickly as normal glass.
Materials and Finishes
Damaged paintwork, joinery, and carpets
Replace damaged materials and finishes with healthier and more
environmentally friendly options.
If replacing entire window frames, aim for thermally broken aluminium or
wooden/PVC frames as these perform the best at keeping the heat in and
stopping condensation forming on the windows. This is also a good time to
reassess the necessity for windows on colder, less sunny sides of the house
(typically southern and south-eastern). Walls lose much less heat than
windows, so consider the option to resize the glazed area, replacing it with a
smaller window and a well-insulated wall.
Improved comfort and better health
Increased capital value of the home
Improved Homestar™ rating
Talk to your builder and window manufacturer/supplier about…
»» Which windows need full replacement of frames and which might just
require new glass.
»» The difference in costs between single and double-glazing solutions.
»» Options for reducing window size on the colder southern sides of the
building and positioning windows on the warmer northern sides to make
the most of the sun’s warmth in winter.
Next steps:
1. Prioritise double-glazing in those windows that need to be replaced on the
colder southern sides of the house as well as main living areas.
2. Investigate double glazing options and benefits.
3. Investigate pricing options for different types of higher performance glazing.
Remove the old damaged system and upgrade with either solar or heat
pump hot water heating. Both systems are significantly more efficient
than the usual electric hot water cylinder and, despite the higher up-front
costs, this will save you money in the long run. Solar works best where
you have a sufficient area of roof exposed to northerly sun throughout
the year. If your house is heavily shaded by trees or other buildings, or
if you don't have any north-facing roof space where solar panels can be
mounted, a heat pump hot water system might be preferable – but make
sure that it is capable of operating efficiently in Christchurch’s climate.
A well installed and efficient system will significantly reduce your daily
water heating costs – by as much as 75%.
Increased capital value of the home
Household running cost savings
Install seismic restraints (straps) around the hot water cylinder, or if badly
damaged, replace with more efficient solar hot water or heat pump hot
water system and upgrade piping and lagging (insulation around pipes).
Cost estimate:
Solar hot water and heat pump hot water system costs vary depending on
size and set-up. An average system could be expected to cost about $5,000
- $6,000 installed. You may be eligible for a grant of up to $1,000 towards
this from EECA.
Improved comfort and better health
Double-glazing will reduce your heat loss in winter and help to stop overheating
in summer, adding to the value of your home.
Broken or damaged hot water system
If replacing the entire system, it could be a good time to reconsider how
efficient your piping is. Try to avoid long lengths of hot water pipe runs
and make sure all hot water pipes have good levels of lagging (insulation)
around them.
Household running cost savings
Cost estimate:
If the window glass or frames need to be replaced due to damage, this is the best
and most cost effective time to upgrade to a more efficient window type. Costs
vary widely due to the difference in size and type but, as a guide, double glazing
is about $80 - $110 more per m2 to replace compared to single glazing. So a small
extra cost for much added comfort.
Hot Water Systems
Floors and Foundations
most heat is lost through the edges of the concrete, rather than through the middle of
the slab down into the ground. If a whole new slab is not required but works are being
carried out to level and repair the slab, investigate options to add insulation to the
Repairing your floor and foundations provides a golden opportunity to upgrade the
insulation, add a ground moisture barrier, strengthen the foundations and potentially
raise the floor level for increased flood protection.
Timber floors:
If suspended timber floors are being repaired or replaced, ensure that they are
insulated with a bulk insulation product of at least R1.4 under the floor. Provided there
is adequate access space under the floor (more than 40cm), take the opportunity to
install an on-ground moisture barrier (usually black polythene) to stop rising damp.
Fix any drainage issues or leaks under the house at the same time. Some people
have found new springs or moisture coming up beneath homes because of ground
movement. To improve performance of wooden floors in areas of ground instability,
ensure the piles are based below the liquefaction layer.
Damaged floors and foundations, cracked concrete slabs and un-level floors
This will vary depending on the type of floor and the extent of the damage. Some
floors will need to be re-levelled, some will require rebuilt foundations, and others
may necessitate a full house rebuild. Foundations are critical to a safe house and
several technical specialists may be required (such as geotech specialists, engineers
and builders). An example of an engineered solution is strengthening the foundations
with tied steel and using compacted hardfill, instead of tailings, underneath any new
concrete floor slab. Whatever the path taken to rebuild your home, the opportunity to
add insulation under the floor should not be missed.
Concrete floors:
Adding insulation under a concrete slab can only be achieved when a new slab is
poured. If this is required, talk to the builder about having a minimum of 50 mm ‘S
grade’ expanded polystyrene (EPS) board over the damp proof membrane prior to the
poured concrete slab. In addition, the perimeter of the slab should also be insulated as
Cost estimate:
Adding underfloor insulation to a suspended timber floor of an average 150 m2 house
would cost about $1,500 - $2,000; and grants are available from EECA to help pay for
underfloor insulation in houses built prior to 2000.
Upgrading floor insulation can keep you warmer and drier and save an average home
up to $250 per year in heating costs
Household running cost savings
Improved comfort and better health
Specify products labelled with an Environmental Choice tick which
have a lower environmental impact. There are a wide variety of building
products that are labelled with the Environmental Choice tick – these
include paints, insulation, plasterboard, carpets and floor coverings
and joinery. Where possible, choose sustainably sourced, recycled or
local products. Look for low or no VOC (Volatile Organic Compounds)
levels in paint, glues, polyurethane and carpets. Minimise resource use
by selecting quality products that are durable, repairable and easily
maintained and use local products and services to support our local
economy and to reduce transport emissions.
Cost estimate:
In most cases, products with Environmental Choice certification are no
more expensive than other similar products.
Environmentally friendly, and low VOC products are healthier.
Increased capital value of the home
Household running cost savings
Improved Homestar™ rating
Improved comfort and better health
Talk to your builder/engineer about…
»» The scope of the damage to the foundation and the potential to add underfloor or
perimeter insulation as part of the rebuild process.
»» The potential to raise the floor level as part of the rebuild in order to protect the
property from newly identified flooding risk in Christchurch.
Next steps:
1. Ensure that all the technical reports and specialist engineering advice relating to
the property are available to the builder.
2. Investigate the potential for financial assistance from EECA for adding insulation
under suspended timber floors.
3. Work out a budget for the work including the additional costs of adding the
underfloor insulation and moisture barrier.
Increased capital value of the home
Improved Homestar™ rating
Talk to your builder/tradesperson about…
»» Specifying Environmental Choice certified products and low VOC
paints and finishes.
Note: Keep invoices and supplier information for Environmental Choice
products used in your rebuild to claim points for a Homestar™ certified
Next steps:
1. Investigate using Environmental Choice products in your rebuild.
Ceilings and Roofs
Damaged ceiling or roof – external or internal
Upgrade ceiling insulation and remove recessed downlights (see
lighting section). Change to lightweight and durable roofing
material. Upgrade or install bathroom and kitchen ventilation.
Build Back
Standard ceilings / roofs (houses with an accessible ceiling
space): Remove damaged linings and any damaged ceiling
joists and replace. Remove and replace recessed downlights
(see Lighting section). Fit thick bulk ceiling insulation between
and over the ceiling joists (ideally as a blanket). Aim for R4.0
insulation or more if you want to be warmer (this may be installed
as a couple of layers and could be 175 mm or thicker, depending
on the type of insulation). Where roofing material is damaged,
replace with suitable new material – consider more earthquakeproof options such as long run steel, rather than heavy tiles, for
your roof covering. Ensure existing extractor fans in bathrooms
and kitchens are vented to the outside of the house (through the
roof or under the eaves), or fit extractor fans if you don’t already
have them.
Internal or external wall damage
If you have to replace the wall linings or external wall cladding this is
the best time to add or upgrade the insulation in the walls.
In timber and steel frame walls, remove damaged linings or external
wall cladding as well as any damaged framing. Increase the bracing
where required. Add insulation and building wrap (building paper).
Replace with new linings or cladding. Add insulation that is at least
R2.6, the higher the better. Note that higher levels of wall insulation
beyond R2.8 may only be possible if you increase the width of the walls
or rebuild completely.
Cost estimate:
The insulation itself isn’t that expensive but fitting it will take the
tradespeople extra time. Allow between $2,200 and $2,800 for the costs
of the insulation for an average sized house, and $1,200 extra for fitting.
Wall insulation will stop heat being lost, keeping your home warmer
in winter and providing as much as $400 worth of savings per year
compared to a non-insulated house.
Skillion roofs (houses without ceiling space): If only the internal
linings are damaged, these can be removed and, if there is
enough room between the linings and the roof, additional
insulation can be added prior to new linings being put on. Your
builder may need to make additional room in the roof cavity by
packing or spacing it out with battens to get extra insulation in.
If the roofing material is damaged, it may be cost effective to have
it removed, upgrade the insulation levels, and have the roof put
back on at the same time. Again, aim for as high an R value as
possible – ideally at least R4.0.
Household running cost savings
Improved comfort and better health
Increased capital value of the home
Improved Homestar™ rating
Talk to your builder about…
»» The best insulation options for your home – and whether it is worth
doing the whole home at the same time.
»» Taking advantage of opening your walls for insulation to also check
your wiring and plumbing. In older houses, it may be cost effective
to re-wire at the same time.
»» Prioritising living areas, bedrooms and the south facing colder sides
of the house first as these will be the ones losing the most heat.
»» Ensuring that insulation is installed in accordance with the
appropriate NZ standards (especially NZS 4246:2006 – see www. ).
Next steps:
1. Find out about grants or loans assistance for insulation from EECA.
2. Work out a budget, including what your insurance will cover and
any financial support for additional costs.
Cost estimate:
The cost of adding ceiling insulation to a standard roof without
any previous insulation is between $2,000 and $2,500. Grants are
available from EECA for all houses built prior to 2000 and these
can cover a third or more of these costs.
Ceiling insulation will stop heat loss through your roof, keeping
your home warmer in winter and cooler in summer. This can
provide as much as $500 worth of savings per year compared to
a non-insulated house.
Household running cost savings
Improved comfort and better health
Increased capital value of the home
Improved Homestar™ rating
Talk to your builder / roofer / electrician about…
»» The damage to your roof and the best options available to get
more insulation installed.
»» Fixing other issues at the same time- such as putting in
ventilation to bathrooms and kitchens - and the order in
which these should be done to minimise damage to the new
»» Replacing downlights at the same time so there are no gaps in
your insulation.
»» Roof colour - lighter roofs reflect heat, keeping the house
cooler in summer.
Next steps:
1. Find out about grants or loans assistance for insulation from
2. Investigate opportunities to install extractor fans with
external venting, and remove downlights.
3. Work out a budget for the work including the additional costs
of better insulation, ventilation, lighting and more suitable
roofing material options.
Damaged light fittings and existing inefficient recessed downlights
Replace downlights and install energy efficient light bulbs while ceilings
and/or lights are being repaired or replaced.
Remove recessed downlights - these act as small chimneys sucking heat
through your ceiling and insulation. Replace downlights and fill holes in
the ceiling and insulation. Surface-mounted fittings could cover and seal
the downlight hole, or install surface-mounted or pendant lights and fill
any gaps in the ceiling plasterboard.
Ceiling or wall repairs offer a good opportunity to reconsider your lighting
needs and options. Consider whether the location, brightness and number
of lights could better meet your needs. Also consider greater control of
your lighting, so lights that you are not using can be switched off. Painting
walls and ceilings in light colours can also maximise the effectiveness of
natural and artificial light.
Switch to efficient lightbulbs, such as compact fluorescent bulbs - these are
easy to install, last longer and can save $100 each, over the life of the bulb.
Cost estimate:
The cost of replacing downlights will vary depending on how many you
have and whether you are repairing your ceiling anyway. As a stand-alone
job, replacing a recessed light fitting with a simple pendant fitting would
cost in the region of $70.
Talk to your builder/electrician about…
»» The most effective lighting arrangement as part of your rebuild.
»» Rewiring for better control of lighting systems.
»» Adding more insulation to the ceiling once downlights have
been removed.
More efficient lighting will reduce energy costs, while removing downlights
will allow you to fill insulation gaps and keep heat inside the home,
potentially saving you as much as $250 per year.
Household running cost savings
Improved comfort and better health
Increased capital value of the home
Improved Homestar™ rating
Next steps:
1. Familiarise yourself with the ‘downside’ to downlights (see the
Consumer NZ report on downlights
2. Find out about efficient lighting options at
3. Draw up a budget to carry out the work.
Find further information on:
Homestar™ measures or rates the performance of your home,
in a similar way to the energy star rating for a washing machine
or fridge. The advice given here closely aligns with the Homestar™
rating tool – so making the effort to build back smarter can increase
the performance, value and comfort of your home. A trained
Homestar Practitioner can provide you with professional advice
about incorporating good environmental design and help you get the
appropriate Homestar rating. Use the free online version of the rating
tool to compare different options for your home
A note on waste
To reduce construction waste going to landfill, and to gain further
points in the Homestar™ rating tool, your builder and tradespeople
should be encouraged to follow REBRI (Resource Efficiency in the
Building and Related Industries) guidelines for waste management.
These provide information and advice on:
»» What materials can be recycled or salvaged.
»» How to develop a waste management plan and system.
»» How to separate and store waste.
For more information, visit:
Government grants for insulation and heating from the Energy
Efficiency Conservation Authority (EECA): www.energywise.govt.
Government grants on water heating:
Government grants for chimney replacement with efficient heating:
Christchurch City Council solar hot water consent rebate: www.
Consumer NZ reports on:
>> Downlights
>> Solar water heaters
>> Heat pump water heaters
Double glazing options:
Calculating your heating requirements:
Environmental Choice products:
Efficient lighting options:
You may also be able to find ways of using waste material around your
neighbourhood, e.g. your old bricks could be someone’s new paving.
Obtaining consent
For general information on
improving your home:
In most cases you will require a building consent to undertake
any major repair work. Talk to your builder or the Christchurch City
Council about obtaining building consent before starting any repairs.
For more information, visit:
Finding tradespeople
Look for membership with reputable associations such as Registered
Master Builders, Certified Builders, or Master Plumbers. Electricians should
be registered with the Electrical Workers Registration Board, and plumbers
and gasfitters with the Plumbers, Gasfitters and Drainlayers Board.
Solar water heater installers must be accredited by the Solar Industries
Association, and wood or pellet burner installers must be accredited by the
NZ Home Heating Association. Heat pumps use refrigerants and therefore
installers should have both electrical and refrigerant certification (HVAC
The Department of Building and Housing has just started a Licensed
Building Practitioner Scheme which has a list of all registered tradespeople
( ). Under new building laws,
tradespeople must be registered with this scheme in order to do certain
kinds of work. Christchurch City Council has also developed a list of
accredited contractors for earthquake recovery work (
Builders’ speak
What is an R value?
The effectiveness of insulation is measured by its R value. The higher
the R value on an insulation product, the more it slows down the
transfer of heat. Generally, the R value of insulation gets higher as
the product gets thicker. For example, an R3.0 product has greater
thickness than a R1.0 product of the same type. Using R values helps
you to compare the effectiveness of different types of insulation.
This pamphlet is a joint publication of:
Smarter Homes
Download two key publications: Your Guide to $marter Living and
Your Guide to $marter Insulation.
Beacon Pathway
Download an in-depth homeowner manual
Consumerbuild, a guide to the process of building and renovating:
Level, more technical detail on home improvements:
Department of Building and Housing website that provides
guidance and information on building code requirements.
Seek advice from:
Community Energy Action Charitable Trust’s free advice service:
for free advice on all home energy matters and associated
renovations. Call 0800 388 588, email
or visit
Community Energy Action Charitable Trust’s insulation and heating
installation service: For free insulation checks and free insulation
and heating quotes (with government subsidies).
Call 374 7222, email or visit
Your local Eco-Design Advisor, free and independent advice
on home design. Home designs can be emailed to advisors
and discussed over the phone or during site visits.
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