Build Back Smarter is a free service providing homeowners with face to face advice on making their homes warmer, drier, healthier and cheaper to run.

Request your healthy home assessment

Cover of the Home Renovation guide [PDF, 1.4 MB]

Home renovation guide

The Build Back Smarter advice service is available to all homeowners and landlords in Christchurch and neighbouring parts of Selwyn and Waimakariri Districts.

It provides free, expert advice about home improvements and is particularly relevant for people undertaking earthquake repairs.

How it works

Build Back Smarter provides free, no obligation, expert advice.

Request your healthy home assessment by calling a provider listed below or complete this online booking form.

  • Community Energy Action phone: 0800 438 9276
  • Energy Smart phone: 0800 777 111
  • AirCon NZ phone: 343 3049 or 0800 161 162

A friendly Build Back Smarter advisor will visit your home and help you prepare a Healthy Home Improvement Plan tailored to your needs and budget. All our advisors wear photo identification.

The advisor will give you practical and specific advice on how to make your home warmer, drier, healthier and cheaper to run.

You have no obligation to undertake any of the recommendations provided by your assessor.

If you choose to undertake work you may like to compare prices from several different companies. Ask your assessor about any funding support or product discounts that may be available. 

Build Back Smarter is an advice service only - the Council does not endorse the products or installation services of the providers listed.

Your Healthy Home Improvement Plan will cover

  • Insulation
  • Heating
  • Ventilation and moisture management
  • Dampness control
  • Lighting
  • Windows and curtains
  • Draft stopping
  • Water heating and water conservation
  • Smoke alarms

New Government regulations require rental properties to have working smoke alarms and insulation, where practicable. A Build Back Smarter assessment can also help check compliance with these new regulations.

Case Study

Where to start

When renovating, make your home warmer, drier, healthier and cheaper to run - it’s your chance to build back smarter.

  1. For a healthy home, you need good: Insulation, Orientation, Heating, VentilationReduce heat loss 
    Stop drafts around doors and windows, boost ceiling, underfloor and wall insulation, use two layers of thermally-backed curtains and when possible double glaze with low-emissivity glass.
  2. Efficiently heat your home
    Capture free heat by improving access to winter sun through north-facing windows, choose an efficient heating system that can heat living areas to a minimum of 18°C and bedrooms to 16°C.
  3. Control moisture at the source
    Remove damp air from your home with an extractor fan in all bathrooms, a range hood in the kitchen and vent your clothes drier outside. Laying a plastic sheet over the ground beneath raised floors also provides an important moisture barrier.
  4. Be water-wise
    Insulate all hot water pipes and hot water cylinders, check your cylinder thermostat is set to 60°C, then choose water-efficient taps and low-flow showerheads, dual flush toilets, and a water-efficient washing machines and dishwashers.
  5. Regularly ventilate your home
    Open windows and doors for a few minutes each day to remove moisture and allow fresh dry air to circulate throughout your home.

How healthy is your home?

temperature gagueCheck the temperature and humidity of each room in your home throughout the year. To meet world health standards, living spaces should be a minimum of 18°C and bedrooms a minimum of 16°C when occupied. Relative humidity should be between 40% and 60%.

The risk of respiratory disease and mould growth in your home significantly increases if household temperatures are consistently below 16°C and humidity is greater than 70%. Home sensors are available from most electronic retailers for less than $40.

Ceiling and roof

drawing of heat loss of uninsulated home

Opportunity Description and Benefits Value
Boost ceiling insulation

Improving your ceiling insulation is the best way to make your home warmer and healthier. Up to 35% of heat can be lost through an uninsulated ceiling.

Boosting insulation by adding another layer over old insulation will help to trap more heat in your home. Fit insulation between and completely over ceiling joists so it looks like a thick continuous blanket across you roof space (provided no downlights are in place). Aim for an R value of 4 or at least 17 cm of insulation depth.

Be aware of gaps. Even small gaps can dramatically reduce the performance of your insulation.

Avoid 35% loss from your home – saving up to $500 per year.

An insulation top-up for an average home can cost $1000.

Insulating an uninsulated ceiling can cost $3000.

Financial help is available depending on personal circumstances.

Check insulation does not cover down lights. If your recessed down lights are labelled non-IC or CA (see lighting section), they must not be covered with insulation otherwise they are a potential fire hazard. Heat can build-up around lights and ignite ceiling material. Most down lights require a gap around them to release heat.

Avoid a fire risk.

No cost to check down lights.

Replace all non-IC-rated down lights Choose pendant lights that hang from your ceiling or IC and IC-F-rated down lights to avoid heat loss through your ceiling. Further cost savings can be achieved by using LED bulbs (see lighting section). Less heat loss through your ceiling and lower running costs for lights.
Change to lightweight durable roofing material. Consider replacing heavy roofing materials such as concrete tiles, with light-weight and durable materials such as coloured steel. A light-weight roof will be more earthquake resilient. Improved resilience to earthquakes and less maintenance.

Windows and Doors

Diagram showing heat loss through doors and windows

Opportunity Description and Benefits Value
Stop drafts

Stopping drafts is one of the simplest and cheapest ways to make your home warmer. Gaps around windows and doors allow cold air to enter and leak warm air outside.

Self-adhesive foam, rubber or V Seal tapes can easily be attached around the frames of doors and windows. Brush strips can be screwed to the bottom of doors and flexible silicon-based sealants can fill gaps.

Less cold drafts from doors and windows.

Typically 10% of home heat is lost through gaps.

$40 for 10 meters of adhesive draft stopping.

Two layers of curtains

Good curtains can dramatically improve your comfort and lower heating costs.

Use two layers of full length thermally backed curtains. A second layer can simply be attached to the inside of your existing curtains.

Choose close-fitting curtain tracks, which act like small pelmets above windows, to stop warm air at the ceiling being drawn onto cold windows and circulating cold drafts round the room.

Close your curtains early to trap in the day’s heat and to block out cold through the night.

Typically 35% of home heat is lost through windows.

Stops cold drafts across the floor. Second layer of curtains $30 per linear meter.

Free from the Community Energy Network Curtain Bank.

Secondary glazing

Secondary glazing is a relatively low-cost way to improve the thermal performance of your windows and reduce condensation.

Plastic film window kits can be taped onto wooden window frames or hard acrylic sheets can be cut to size and attached by magnet to the inside of your windows. Both options work well to improve heat loss and eliminate condensation but have a shorter life than glass double glazing.

Typically 35% of home heat is lost through single glazed windows.

Plastic window kit – $10 per window Magnetic acrylic secondary glazing – $250m2.

Double glazing Double glazing is a long-term solution to reducing heat loss and condensation. A gap of at least 12 mm between window panes is recommended. Double glazing can almost halve the heat lost through windows in comparison to single glazing. Choose Energy Star-labelled windows for the most efficient options.

Typically 35% of home heat is lost through single-glazed windows.

Double glazing – $400m2.

Low-emissivity glass Low-emissivity glass (Low-E) is an invisible coating that lets in light and acts like a mirror reflecting radiant heat back into your home. Low-E glass can reduce heat loss through glass by a further 20% with relatively minimal cost.

20% less heat loss through windows.

5% cost increase over standard glazing.

Window frames

Window frames made from insulating material like wood or plastic (PVC) reduce heat loss and condensation.

Because aluminium transfers heat and cold extremely well, a small thermal break is needed to make the frames work properly reducing condensation forming on the frame and around the edges of windows.

15% less heat loss and less condensation.

25% cost increase over standard frames.

Capture the sun through windows

Aim to maximise the sun’s warmth during winter and limit overheating in summer.

Appropriately size and locate windows and doors - most on the northern side and least on the southern sides of your home.

Use eaves, trees or external shading to reduce overheating in summer especially on the north and western side of you home. Ask your builder about passive solar design or refer to www.level.org.nz(external link) for more information.

1m2 of north facing window is equivalent to a 1 kilowatt heater in winter.

Home Heating

Close fitting curtain rails reduce drafts and heat loss

Home heating is often the largest contributor to your energy bills (making up 35%). Choose the most energy-efficient source of home heating you can afford, sized and located appropriately for your house. Options include a heat pump, electric heater, gas fire or a clean air-approved log burner or pellet fire. Energy Star-labelled appliances are the most energy efficient, so will cost you less to heat your home. Aim to warm living spaces to a minimum of 18 degrees and bedrooms to a minimum of 16 degrees. 

Comparative heating costs for a range of home heating options

Fuel Appliance Energy Efficiency Output (kw) Installed Cost ($) Heating Cost ($/hr)
Electricity Fan heater 100% 2.4 30 0.57
Electricity Oil column heater 100% 2.4 170 0.57
Electricity Raidant bar heater 100% 2.4 80 0.57
Electricity Night store heater 80% 3.4 1,400 0.61
Electricity Heatpump 370% 5.4 2,750 0.34
Electricity Heatpump central heating 330% 14.0 15,000 1.00
Electricity Ground source heatpump central heating 400% 15.0 32,000 0.89
Gas Flued gas heater 80% 7.0 5,400 1.66
Pellet Pellet fire 82% 9.5 5,100 1.16
Wood Free standing log burner 70% 16.0 3,500 0.86
Wood Enclosed log burner 65% 14.0 3,500 0.81

Source: Environment Ltd, heating choices and costs for Christchurch 2013

Portable gas heaters are not recommended

The continual use of a portable gas heater is not recommended. Portable gas heaters burn LPG, but have no chimney to carry away emissions. This releases into your home harmful gases such as carbon monoxide and nitrogen dioxide and significant amounts of moisture contributing to condensation. Because of this, gas heaters should only be used with an open window and at times of emergency such as during a power cut.

Appliance Advantages Disadvantages Best used for
Heat pump

Very efficient form of heating.

Wide range of sizes and outputs.

Quick to heat a room.

Able to heat and cool.

Highly controllable with built in settings.

Safe form of heat.

Able to filter the air.

Performance can drop when very cold outside.

Need to clean filters.

May need multiple units to heat whole house and large external unit.

Requires qualified installer.

Relatively high purchase price.

Drafty air circulation.

Primary source of home heating Background heating for large rooms.

Summer cooling.

Oil and convection heaters

Often has thermostat and timer.

Portable - often wheeled. Quiet.

Slow to heat up.

Heat rises to the roof.

Can’t heat large spaces well.

Fire risk if covered.

Background heating of a bedroom or small living space.
Radiant heaters

Instant heat.

Portable.

Direct radiant heat feels warm even if the room is cool.

Quiet.

Fire risk if it falls over or is placed too close to furniture or clothing.

Hot surface could burn if touched.

Often limited in size / output.

Spot heating of a person for a relatively short time.
Panel heater

Thin wall mounted panel.

Takes up little space.

Often has a thermostat and timer.

Quiet.

Very low heat output.

Relatively high cost for heat.

Not to be placed on an uninsulated wall because of heat loss.

Background warmth for small well insulated rooms.
Fan heater

Low cost.

Instant heat.

Often has thermostat.

Limited in size / output.

Drafty with air circulation.

Noisy.

Heating small spaces quickly.
Flued gas fire

Fast to heat.

Easily controlled, often has thermostat and timer.

Provides both radiant and convection heat.

Provides aesthetics of fireplace.

Relatively expensive.

Requires electricity to run.

Uses non-renewable fossil fuel.

Good if house already connected to mains gas supply.
Wood burner

Provides radiant and convection heat.

Large heat output range 8 kW to 30 kW.

Affordable form of heating.

Can run without electricity.

Can combine with wetback in some areas.

Can combine with heat transfer to heat whole home.

Relativity low running costs.

Requires effort and space to store and cut wood.

Ash and chimney cleaning can be messy.

Contributes to air pollution.

Requires building permit.

Creates a fire risk.

Needs a fire safety guard.

Relatively high purchase price.

Heat large areas.

Where wood is readily available.

When power cuts are possible.

When difficult to insulate home.

Pellet fire

Very clean burning.

Easily controlled - with timer and thermostat.

Less handling of wood. Can combine with wetback in some areas.

Requires electricity to run (although some come with batteries).

Mainly convective heat.

Smaller heat output 8-15kW. Pellets can be relatively expensive.

Requires building permit.

Heating large areas.

People who want a wood burner but without the effort of handling wood.

Water Heating

Opportunity Description and Benefits Value
Choose efficient water heating Hot water heating can make up 30% of your home’s energy bill. Choose the most efficient form of hot water heating you can.
graphic of efficient water heating optionsSource: Home Performance Advisor Manual
Various purchase prices and running costs.
Install seismic restraints for cylinders and tanks Many water header tanks and hot water cylinders were affected by the Canterbury Earthquakes. Adding strapping and bracing around these heavy tanks should be considered to prevent future damage.

Future-proofing your home.

Minimal cost.

Insulate all hot water pipes Wrap insulation or lagging around all hot water pipes. This is especially important for pipes nearest to your water cylinder because this is where the greatest amount of heat is lost.

Less time waiting for hot water to reach your tap or shower.

$5 per meter.

Insulate your cylinder Most hot water cylinders, even new ones, give off heat. By placing an insulation wrap around the cylinder you can trap in heat meaning you will spend less on heating water.

Save on average $100 per year.

One-off cost $70 for a cylinder wrap.

Consider solar hot water Solar hot water systems are ideal for larger families or for people who use lots of hot water. You can typically save about 70% of your hot water heating costs by using a solar system. $7000 - $10,000 for a solar hot water system.
Ask about night-rate water heating Electricity is substantially cheaper overnight when there is less demand. If you have a large hot water cylinder, you can enjoy the benefits of this cheaper electricity by heating water overnight. Check with your electricity supplier to see if night-rate water heating will work for you. Night time electricity rates can halve your water heating costs.

Ventilation and moisture management

A damp home is much harder to heat and can lead to condensation and mould problems. It is best to control moisture at its source rather than treat the symptoms of a damp home. Using a dehumidifier or mechanical ventilation system could be considered only after all other options to prevent moisture in the home have been taken.

Opportunity Description and Benefits Value
Install a kitchen range hood Install a kitchen range hood to remove unpleasant cooking odours and moisture from your home. Cooking is a significant source of moisture and odour in the home. Regular cleaning of the filters also helps maintain good air flow. Avoid cooking odours and three litres per meal of moist air saturating your home.
Install extractor fans in all bathrooms All bathrooms should have an extractor fan (minimum 120mm in diameter) vented to the outside. Fans should be left on for at least five minutes after showering. An open bathroom window is seldom used over winter when moisture problems are exacerbated by cool, wet weather

Avoid 0.5 litre per shower of moist air saturating your home.

$120 plus installation.

Consider a shower dome Eliminate bathroom condensation by placing a plastic lid over your shower cubical. Shower Domes trap in moist air and give you a warmer shower. You will still need to ventilate the bathroom and shower to manage mould that may grow on damp surfaces.

Avoid 0.5 litre per shower of moist air.

$250 includes installation.

Vent your clothes dryer outside Ensure your clothes dryer expels the moist air to outside your home.
Avoid drying clothes inside on clothes racks or in front of wood burners which significantly adds to dampness in your home.

Avoid four litres per wash of moist air saturating your home.

$90 for ducting plus installation.

Dry your clothes outside

Drying clothes outside is a great way to avoid moisture in the home and natural UV from the sun helps to purify clothes.
Place your clothes line in a convenient sunny location and, if possible, take clothes in before the evening gets cool to avoid the need to finish drying damp clothes inside.

Avoid four litres per wash of moist air saturating your home.

Free, once an outdoor clothes line is set-up.

Open windows and doors everyday Opening windows and doors for just a few minutes each day is a great way to remove moisture and allow fresh air to circulate throughout your home.
Windows that have ventilation latches or security stays are useful to securely allow fresh air to circulate through your home.

Fresh dry air replaces damp stale air making the home easier to heat and healthier.

Free.

Floors and foundations

 

Insulated underfloor and ground moisture barrier

Opportunity Description and Benefits Value
Install a ground moisture barrier Homes with an enclosed subfloor space should have a heavy-duty plastic ground sheet laid over the soil and placed securely around foundations to prevent dampness entering the home from moist soil below. Rising damp is a particular issue for Christchurch because of the high water table and moist soils. Eliminate rising damp. 30% of household moisture can rise from the damp soil beneath the home.
$17 per m2 installed.
Install underfloor insulation Homes with sufficient space beneath raised floors should have underfloor insulation installed. Aim for an R value of 1.4 using bulk or ridged insulation materials. Silver foil insulation is no longer recommended because more durable and effective options are available. Up to 14% of home heat is lost through an uninsulated floor.
$18 per m2
Insulate the perimeter of concrete slab floors If you are pouring a new concrete slab foundation, talk with your builder about perimeter insulation. Most heat is lost at the edge of a concrete floor.
A range of options and products that use a thermal break within the edge material are available. This is essential if you are planning underfloor heating.
Significantly reduce heat lost through concrete floors.
Keep your underfloor vents clear If you have a raised floor, make sure any underfloor vents are clear of vegetation or building work to adequately remove moist air from beneath your home. Manage rising dampness.
Free.
Check for leaks Regularly check around and beneath your house for leaks, overflows or puddles. Poor site drainage and plumbing defects can be a major source of rising dampness and can damage your home. Maintain proper drainage.
Free.

Lighting

LED colour range

LED colour range

Opportunity Description and Benefits Value
Switch to LEDs LEDs (light emitting diodes) can be used in all modern light fittings. Most commonly, people prefer warm/soft coloured lights (3000k or less). White lights could be considered for your bathroom, kitchen, workshop or outdoor areas (more than 3000k).

Saving of $100 per year per LED bulb, plus up to 30-year life.

Purchase price $10 - $20 per bulb.

Use pendant lights Recessed down lights restrict the amount of light cast by each bulb meaning that you will need many more lights to adequately illuminate a room in comparison to pendant lights that hang from your ceiling. Fewer lights means less costs.
Use IC-labelled or IC-F-labelled down lights IC-labelled and IC-F-labelled recessed down lights are able to have insulation placed completely over the light fitting. This stops down lights acting like small chimneys sucking heat from the room and heat being lost through the gap in insulation required around non-IC-labelled lights.

Saves home heating costs.

Purchase price $70-120 per light fitting.

Personalise your lighting control Consider the location and zoning of light switches to enable you to turn off sections of lights when not needed. Consider dimming switches to allow you to change the mood of the room. Check that your LED bulbs are able to be dimmed if needed. More control of lights and lower running costs.
Capture natural light Allow natural light to enter your home with north facing windows, and limit the size and number of windows facing south. Consider sky lights or solar tubes to allow natural light to illuminate darker spaces in the house.

Brighter internal spaces using daylight.

Solar tube or skylight purchase price $600 - $2000.

Light entranceways, stairs and hallways. Lighting of entranceways, stairs and hallways is vital to avoid trips and falls. Ensure that these places are adequately lit and that a light switch is accessible from the top and bottom of stairs and each end of hallways. Improved personal safety

New Zealand Down light fittings Classifications

New Zealand down light fittings classifications

 Diagram of how non-IC labelled downlights cause heat loss

Garden and outdoor areas

Opportunity Description and Benefits Value
Face the sun Enjoy winter sun and cool summer shade. Outdoor areas and north facing windows should capture winter sun. In summer, use features such as overhanging eaves, deciduous trees, awnings or umbrellas to stay cool. Warmer home in winter and cooler in summer.
Escape the wind You will enjoy outdoor living more if spaces are sunny and sheltered. Use your home, structures or trees to provide shelter from cold prevailing easterly winds and if possible, orient outdoor living spaces toward the north or west. Enjoy outdoor living.
Grow edibles Enjoy fresh, healthy and delicious fruit, vegetables and herbs grown at home. Include edible trees, shrubs and raised beds in your garden. For information about what varieties are suited to Canterbury visit www.edible.org.nz(external link). Delicious home grown food.
Compost at home Feed your garden with compost made from your household food scraps, lawn clippings and garden trimmings. Why pay for fertilizer when you can easily recycle organic nutrients at home. More productive soils and less waste.
Go native Native plants are hardy, require less maintenance, less watering and attract birds. Choose a mix of plants that provide year rou