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</