Somerfield 1

Back to Existing Homes

Somerfield homeowners Rex and Susan have come home to a substantially warmer and drier home after their earthquake repairs included Build Back Smarter upgrades.

Prior to the earthquakes, the homeowners had taken what they thought were the best steps to reduce the dampness of the house and installed the positive pressure ventilation system, even though there was only a low level of insulation in their ceiling.  The homeowner reported this had a slight improvement on the overall level of dampness in the house but that there was still mould growing in some rooms. 

“The house was so damp that if I brought papers home from work, they would absorb so much moisture they wouldn’t go through the fax machine any more” said Susan.

As part of Build Back Smarter, the family had ceiling, wall and floor insulation, a ground vapour barrier, new wood burner and heat transfer system, and an externally vented range hood intalled while their home was repaired.

Rex and Susan  immediately noticed the reduction in moisture in their home, a notable improvement in warmth, and the absence of condensation on the windows.  In particular, the lack of draughts and improvement in temperature of the floor was noticed.  The house was also noticeably easier to heat with the heat transfer system giving good results.

“It’s great no longer needing to wear socks to bed - or having to put slippers on to get up in the morning.“

The delays experienced leading up to the repair process (which commenced 2 years following the earthquake damage occurring), and then in the timeframe for repairs - the repairs took 21 weeks instead of the 14 expected - were very stressful for the household of two adults two children.  They lived in 2 rental units, and then for the last week in a caravan on site during the repair process, all of which was disruptive to both work and the children’s schooling.

Susan and Rex saw significant value in the Build Back Smarter approach, and found the house assessment useful, wishing that they had had this done prior to getting the positive pressure ventilation system installed. 

The homeowners spent approximately $45,000 incl. GST themselves on the upgrade of the kitchen, laundry, hot water system and wood burner, the maximum amount that they could afford to add to their existing mortgage. If they had to have funded the upgrades themselves, they would have reduced the scope of their kitchen upgrade to pay for the insulation.

In terms of actions which weren’t taken but were recommended, the homeowner indicated that they would have liked to get the bathroom extract vent ducted so that it went directly out the wall, rather than the current inefficient arrangement.    


Earthquake damage

The house suffered from significant damage to foundations from the earthquakes.  Ground movement caused uneven settlement of ring foundation and piles, damage to sewer and stormwater drains, the concrete terrace, external paths and the driveway.  All interior lath and plaster ceiling and wall linings were badly cracked.  Because of the foundation failure, repair also required the removal of the internal brick chimney.

In terms of the scope of the earthquake repairs:

  • The house was jacked up and the concrete ring foundation replaced with timber piles and baseboards
  • Lath and plaster ceiling linings were replaced throughout
  • Lath and plaster wall linings replaced throughout
  • Doors and windows were eased and adjusted throughout
  • The concrete deck was replaced with a wooden deck
  • Driveway, paths and patio paving were replaced
  • Sewer and stormwater drainage was checked and minor repairs were made
  • The house was re-wired at the insurer’s cost.


The upgrades

Pre-upgrade condition


  • Thin (<70mm) fibreglass ceiling insulation
  •  R 3.2 blanket overlaid on top of existing insulation. 
  • No wall insulation or building wrap
  •  R 2.8 Wall insulation installed in whole house with building wrap segments inserted between the frames 
  • No underfloor insulation
  • Damp under floor
  • R1.6 underfloor insulation installed
  • Polythene vapour barrier installed
  •  Draughty external doors 
  •  Draught excluders installed
  • Old (1960s) hot water cylinder with wrap and lagged pipes
  • New hot water cylinder installed by homeowner 
  • Old inset woodburner in lounge.  Electric heaters used in bedrooms.
  • New low emission woodburner installed as part of earthquake repairs.
  • Heat transfer system installed taking heat from lounge to bedrooms.

  • Old ineffective extract vent in kitchen window.
  • New rangehood externally vented installed by homeowner.
  • Ineffective bathroom extract vent - combined vent/light unit with long duct and bad location.
  •  New bathroom extract ventilation was supposed to be installed in better location.  Builder didn’t replace unit because contractor felt it was adequate. 

  • 30-Oct-2013 (Report BBS/11)

    Somerfield 1: Build Back Smarter Case Study (PDF 526KB)

    Lois Easton

    Using the case studies of ten homes, the Build Back Smarter pilo project is exploring and demonstrating how homes can be upgraded as part of earthquake repairs.  This report documents the fourth completed case study - the upgrade of a house known in the project as Somerfield 1. 

‹ Back: Spreydon 1

Next: Mt Pleasant 1

Somerfield 1 raised for foundation repair

Raising the house for foundation repair (above) meant underfloor insulation could be installed (below)

Underfloor insulation

Uninsulated walls

Replacing the lath and plaster linings (above) was the perfect time to install wall insulation (below)

Wall insulation

Logo, Homestar

The upgrades took Somerfield 1 from 2 stars to 5 stars

Logo, BBS

Living in Christchurch?

Make the most of the new Build Back Smarter Service

Christchurch   City Council has launched a free service for Christchurch people   rebuilding or repairing their earthquake-damaged homes to provide   advice about insulation,  heating methods and energy saving measures   such as double glazing,  ventilation and lighting.

Homeowners   can contact one of the service’s assessment providers who will prepare a   healthy home improvement plan tailored to the needs and budget of the   home owner.