Design Case Studies with Altherm Window Systems: Drift Bay house by Kerr Ritchie Architects

Happy New Year everyone, and welcome to the first in our new series of Design Case Studies, which will run weekly here on our blog. 

The Design Case Studies are created to give you insight into the building process of some of the amazing homes in the magazine, so the owners can share some of the lessons they learned with you. The series is brought to you in association with Atherm Window Systems. 

The first Design Case Study visits Pete Ritchie and Bronwen Kerr of Queenstown's Kerr Ritchie Architects and talks to them about how they allowed themselves maximum flexibility and minimum fuss with the construction of their home at Drift Bay on Lake Wakatipu. The photographs are by Paul McCredie.

Pete Ritchie and Bronwen Kerr's home in Drift Bay, near Queenstown.

Architects often say that when they get to design their own homes they have a duty to experiment, and Pete Ritchie and Bronwen Kerr’s home on the shores of Lake Wakatipu is no exception. When architects are their own clients, they also tend to leave their documentation until the last minute. For both of these reasons, Pete and Bronwen decided to hire a builder on a labour and materials arrangement, instead of a fixed-price contract (in which the builder agrees to complete the work on a house for a previously agreed price). “It seemed like a fair way to build and there was flexibility along the way,” Pete says. “Plans don’t have to be quite as tied down, so there’s more scope to move throughout the project. There was a certain amount of experimentation going on, and the builder enjoyed that – although it's not always what we would recommend to our clients, as many want more price certainty.”

Pete Ritchie and Bronwen Kerr of Kerr Ritchie Architects.

This arrangement allowed for small but important changes along the way, changes that would have involved potentially time-consuming renegotiation of a fixed-price building contract. For example, what was intended to be a large storage cupboard in an area at the centre of the house was changed into a room containing a pellet boiler to heat water for the underfloor heating system after Pete and Bronwen investigated heating options and decided a boiler was essential. In another case, they decided not to clad an external wall in cedar, but were able to arrange with the builder to use the leftover timber indoors instead. This flexibility minimised the potential stress of making big decisions a long way in advance. Instead, Pete and Bronwen had the luxury of refining details as the building evolved.

A view of the home with The Remarkables rising behind.

The couple started out with the intention of designing a “lean” house containing enough room for them and their three children, as well as a studio to allow them to run their architecture practise from home. Initially, they hoped to complete the house for somewhere around $2000 a square metre, a target they’d achieved on a home they had previously designed for themselves in Wellington.

The home's studio (where Pete and Bronwen work) and guest bedroom is in the volume at left, with the living areas and three additional bedrooms at right. The eastern courtyard, shown here, connects with the kitchen and catches the morning sun.

By the time building started on their Queenstown house in 2006, prices for building and materials had increased, meaning the cost of the new house came in closer to $2500 a square metre. Fortunately, the increase in the value of their lakeside land in the years between their purchase of it and the erection of their home gave them the ability to borrow more money to cover the extra cost.

The home's main living area looks north across Lake Wakatipu towards Queenstown.

Some decisions they made along the way helped keep costs down, but these choices were always made with the overall aesthetic of the building in mind. Inside, they made the economical choice of strandboard panels for doors, joinery and some walls, instead of the more expensive hoop pine they were initially considering. Now that the strandboard is installed, it feels perfectly in keeping with the home’s casual aesthetic.

The kitchen looks out to the courtyard. The staircase at left is
clad in Strandboard panels, which helped keep costs down
and fit the home's casual aesthetic.

The home's living area features cedar detailing that is also used on the exterior.

The other decision they made in order to save money was for Pete to become the builder’s labourer. The couple had just relocated from Wellington to Queenstown and didn’t have a great deal of local work on at that time, so the arrangement made financial sense and also gave Pete valuable insight into the building process (as well as making it clear that working outside in the middle of a Queenstown winter can sometimes be a bit grim).

 

One of the home's bathrooms features a sauna and a sliding door that opens to the garden. The walls feature 'Vixel' glass mosaic tiles.

Now, with their own home and a number of other commissions completed, the couple say they have a good handle on budgetary matters, but they also emphasise the role the client must play (along with a quantity surveyor or builder) in managing their expenditure. “We’ve found that a lot of clients want to manage projects themselves, and they call on us as required,” Pete says. “Some clients are very hands-on and have the time and capability to get involved in aspects of the building process, while others would rather keep more of a distance.”

A view through the house from the entry to the studio.

Q+A
Bronwen Kerr and Pete Ritchie

HOME Why did you decide on a labour and materials arrangement (in which a builder is effectively paid by the hour and for the materials used) with your builder instead of a fixed-price contract? 

Pete Ritchie: We had a good friend who was the builder, and because we know the industry we could source some materials ourselves. We were our own project managers, and to work like that you need a builder who you trust. A labour and materials arrangement is a pretty open and honest kind of system. We didn’t want to pay a huge premium for a fixed price, and nor did we want the builder to make a loss on the job. So it seemed like an appropriate way for us to work. Architects do have experience and expertise that not everyone else has. This gives them more confidence to work this way. 

HOME You worked as the builder’s labourer. Is that an experience you’d like to repeat? 

Pete Ritchie: On the whole I enjoyed it – I also painted the house myself and stained all the weatherboards. That saved quite a bit of money. But in the middle of winter weeks can go by without you seeming to make much progress, and it’s a bit grim and very cold and you have smoko around a campfire. 

HOME Was the process of building your own place helpful in knowing about budgets? 

Pete Ritchie: It gives you a good idea of where clients are coming from. We naturally tend to be conservative with budgets, and we don’t try to extend clients. The process gave us a really good foundation of understanding where costs lie and how to work within a budget. 

HOME When you learned the house would cost more than you originally intended, did you think about revising the plan, and reducing the home's size? 

Pete Ritchie: We didn't really feel we had any option but to carry on as we had originally planned. We had certain needs and requirements which included the studio we work from. It's not a particularly fat house, so there wasn't much to trim off. We weren't in the mindset of creating a house that was oversized anyway.

The home is clad in dark Colorsteel.