Makatoa-Lietz family home
Katja Lietz and Maka Makatoa turned their two bedroom bach at Huia, on the shores of the Manukau harbour west of Auckland, into a four bedroom family home.
The original (1940s or 50s) bach was just under 70 square metres and had two bedrooms. A concrete-floored garage, which had been added after the bach was built, provided extra space which they used as an office and rumpus room. The home was sunny and cosy, had sea views, and its bush surroundings meant it wasn’t visible from the road. But, with four children aged from two to 13, it just wasn’t big enough.
“We wanted to retain the cosiness and the feel of the old bach,” says Katja. “But we also needed two more bedrooms and a home office, and space for members of the family to get away from each other.”
To make the most of the sea views and to minimise impact on their north-sloping site, they decided to build up. After talking to an architect friend, they realised they couldn’t rely on the bach’s structural strength to take a second storey, so they opted instead to build on top of the garage – with an overhanging extension to provide extra living space and a covered outdoor living area.
“We knew that we wanted a home that was energy and water efficient and that had as little impact on the planet as possible,” says Katja. “So we set some priorities early on to know which battles to fight. Luckily we had a great builder and with his help we managed to achieve many of the things we set out to do.”
Heating and cooling
The main glazing in the living area in the original bach faced north-west and west, which was ideal for the sea views and also provided good access to sun. In winter, it was light, cosy and easy to heat, while in summer it could get quite hot.
With the renovations, they:
- turned the garage into a kitchen which faced north-east for morning sun
- put a living area on top of the garage, facing north-west for views and afternoon sun
- kept the existing bach living room as a second living area, also facing north-west.
On autumn and winter mornings, the sun pours in to the kitchen through large bi-fold doors. This heats the tiled concrete floor, which stores the heat throughout the day. The heat is released in the evenings, warming the kitchen area. In summer, the sun is kept out by the eave formed by the overhanging upper story. “This also keeps our shoes dry outside the front door,” says Katja.
Because the other living areas face north-west, they get good sun in the afternoons.
To ensure the upstairs living area doesn’t get too hot in summer it has sloping ceilings and high windows that provide ventilation and allow warm air to escape. These windows are kept slightly open all summer. Wide eaves also provide shade in summer. “If it does get too warm we can sit in the kitchen which is lovely and cool in summer,” says Katja.
Backup heating in winter is provided by a woodburner, which is located centrally and downstairs. “We find that this heats the whole house quickly because the heat rises. We have quite a few fruit trees on our property and there is generally enough wood from pruning for heating.”
Katja and Maka installed high levels of insulation in all of the new parts of their home – far higher than the Building Code required. They also retrofitted the underfloor of the old bach with polystyrene insulation. There was already insulation in the ceiling.
They considered double glazing but, because the climate is relatively mild, decided the money would be better spent on insulation and solar water heating. Instead, they made thermal roman blinds out of duvet covers. “There are lots of fun designs available and they are cheap. We slipped lining inside and sewed them up into blinds. Pockets of still air are formed between the three layers of material and this provides good insulation.”
Energy efficiency
As well as using the sun’s energy for heating, Katja and Maka:
Installed a solar hot water system in combination with a wetback.
- use bottled gas for cooking – they like cooking on gas, but also regard it as more energy efficient to use the gas directly than to use electricity that has been generated from gas
- use compact fluorescent bulbs, and avoided recessed ceiling lights which can compromise the performance of ceiling insulation
- have a washing line in a covered area and don’t have a drier – Katja says they have found this “quite manageable” even with two children in cloth nappies at times.
The solar water heating has an electric booster which they turn on manually when required. “We hardly have to,” says Katja. “We have a large corner bath that fits all the children and its nice to have a guilt-free bath after a sunny winter day when there is plenty of free hot water.”
Water efficiency
Katja and Maka are on town supply but not on the town sewage system in Huia. They decided to install a 5000-litre rainwater tank to supply everything in the house except for the cold kitchen tap and one outside tap. They have low-flow showerheads and a 6/3-litre dual-flush toilet, and they don’t have an in-sink waste disposer – they compost instead.
The kitchen tap provides drinking water. “We felt it was safer to use town supply for drinking because we have lots of trees close to the house and therefore quite a few leaves falling into our gutters. When we run out, we top the tank up from the town supply. Because it rains frequently in Auckland and even more on the west coast where we are, we find that we only run out a few times in summer.”
On-site sewage treatment is via a sand filter system. “We picked this because it has few moving parts and uses little power, but cleans the water to a high standard.” They wanted to install composting toilets, but found that even though they had support from their local council (Waitakere) the Auckland Regional Council would have made it difficult and costly.
Materials
To minimise environmental harm and protect their family’s health, Katja and Maka were careful about their choices of building and finishing materials. They:
- used no tropical timber or other timber from unsustainable harvesting – most of the timber used for framing and so on was radiata pine, and eucalytpus was used for their new deck
- used Environmental Choice certified paints – these are lower in volatile organic compounds which ??(fumes can contribute to asthma and other health problems)
- used second hand materials where practical (“We like old things, and we were on a budget,” says Katja); this included a second-hand back door and a second-hand kitchen which cost just $500 and had the benefits of a steel bench, a double sink, and being made from timber rather than MDF
- used second hand furniture such as an old kauri school table that they use as a dining table
- sold many of the things taken from the old batch – this earned them some money and meant the items sold would be re-used instead of being dumped
- used sea grass carpet
- used tiles on the kitchen and bathroom floors that were made locally and laid by a local artist
- used materials that would last and were largely maintenance free, such as tiles for the bathrooms, ceramic basins and toilets and fibre cement sheet and batten cladding.
Blending in with the environment
The house is designed to blend into the slope, rather than stick out. The roof slopes the same way as the ground, making it less intrusive – it is hardly visible from the road. “We like bright colours and the old bach was bright yellow,” says Katja. “However, we decided to paint the new part green to blend into the surrounding bush. We will eventually repaint the old part to match.”
By building a two-storey house, less land was taken up. This reduces stormwater runoff, as does their use of a rainwater tank.
Flexibility
Though people suggested that Katja and Maka should design open plan living areas, they decided not to. Keeping living areas separate has given them more flexibility about how each room is used. “We still have the old bach lounge which has a woodburner and is a cosy place to read while others are watching TV in the upstairs lounge,” says Katja. “Or, the kids can play with their friends in the downstairs living area, while we have peace and quiet upstairs.”
The large kitchen/dining room provides a third living area where people can sit and read or children can do homework.
A loft, accessible off the upstairs lounge, is used as a home office, but can double as a guest room.
Getting help
Katja works in the sustainability field so had quite a bit of prior knowledge about eco building – but still relied on others’ help and expertise – including an architect friend, their builder, the Waitakere City Council which helped them work out what to do about wastewater and also provided a subsidy for the rainwater tank, the solar water heating installer, and the artist/tiler “who did a fantastic tiling job”.
