THE HEALTHY HOME DESIGN GUIDE

 

HEALTHY HOMES CASE STUDIES

Joseph Lyth: Lower Saddle House, Tahekeroa, Makarau

Project Type Single Residential Passive House Certified Home

 

Project Location Dates: Lower Saddle House Tahekeroa, Makarau 10/2018 – Ongoing (Scheduled completion Feb 2021)

 

Architect: Joseph Lyth

 

GFA: 100m2 Ground Floor 69m2 First Floor 56.5m2 Covered Deck

 

TFA: 122.3m2

 

Cladding Structure: Stained Board & Batten, Trapezoidal metal roofing

Formance SIPs – 115mm walls, 215mm roof

3604 suspended timber floor on piles. 2 x 115mm R2.9 Mammoth insulation

 

Windows: Bertrand timber/ aluminium triple glazed

 

Ventilation: Stiebel Eltron LWZ 180 Ducted HRV System

 

Hot Water: Stiebel Eltron WWK302H hot Water Heat Pump

 

 

Lower Saddle House is the future home of Architect Joseph Lyth, his wife, and two daughters.

 

The Lyths moved from the UK in 2016 and spent several years living in typical NZ code homes, with no designed in heating or ventilation, high energy bills, interior condensation & mould issues, and sleepless nights listening to their girls coughing every winter.

 

Like most people, they slowly built up a small deposit with which to buy a home, however they were loath to purchase an existing building due to their experience of existing homes, and Joe’s knowledge as an Architect of the failings of the current building code, and his experience of issues with existing housing through his work.

 

With some knowledge of Passive House Certification from his time in the UK, and after undertaking a Passive House Designer introduction course, Joe decided that a Passive House Certified home was the way to go, to provide a healthy home for his family to grow up in. Despite having a low deposit they managed to purchase a rural section 45 minutes north of Auckland with a 20% deposit, subject to an agreement with the bank that they’d begin building a property within 12 months. Subsequently, the deposit would be 10% of the overall land & build cost. Due to the low deposit, the bank stipulated that only a fixed price contract would be accepted, and that Joe (despite his role as a registered Architect) would not be permitted to project manage the build.

 

Construction in New Zealand is often prohibitively expensive, a factor that contributes to the low quality of our homes, as any increase in performance is often perceived to come along with high cost premiums. Joe and Sarah decided that they would be guinea pigs, and would use their project to show that you can build quality homes in NZ at more reasonable prices, by putting your money into the areas that count.

 

The philosophy behind the project is that it’s easier to upgrade your bathroom or kitchen than your windows or walls; so the majority of the budget is allocated to a high performance envelope, with the key aims being:

 

● High levels of insulation to minimise heat loss & gain through the envelope.

 

● High levels of airtightness to minimise heat loss through air leakage.

 

● High quality windows to allow light in while preventing too much solar gain.

 

● A heat recovery ventilation system, to retain heat while ensuring the quality of the interior environment.

The interior is simple and functional, with the interior finishes consisting of exposed painted SIPs, plywood walls and strandboard floors. This removed the cost of finishes from the project, while still allowing them to be applied at a later date. The bathrooms and kitchens too are simple, with basic fittings and finishes which can all be upgraded at a later date when budgets allow.

 

The form of the building is intentionally simple to keep costs down, and ensure a compact form factor to aid the buildings performance, with a carefully planned interior layout that provides generous spaces in a compact footprint. Initially the project consisted of a single storey with 3 bedrooms and one bathroom, with the structure designed to accommodate extending into the roof to provide a further bedroom and bathroom at a later date when costs permitted; however due to a low valuation, the end result was an open plan kitchen/ living/ dining space overlooked by a first floor snug area, 4 bedrooms, 1 bathroom with separate WC, 1 ensuite, several storage areas and a large laundry/ utility room all in 169m2 gross floor area.

 

As Passive House is relatively new in NZ the project has to navigate a fair few barriers. Despite sourcing a QS estimate, the initial pricing from a preferred contractor with Passive House experience came back at $780k - over double the initial $375k budget for the build. After a brief regroup, the project was put out to 4 different builders with a more in-depth description of the project aims and specification. Out of the 4, Kane Build Group came out on top due to their experience of SIPs and the quality of their work Joe had seen previously. The budget had had to grow, but luckily had been able to with the help of parents and a small inheritance, so the project proceeded to council consent.

 

Despite concerns due to the non-standard products, recessed window details, etc; the project flew through building consent, with the consenting officer exclaiming “I wish there were more projects like this!” and the only RFIs were querying the hot water system. With a builder and a building consent in place, the project approached the final hurdle – a valuation & approval from the bank.

 

Currently only one Passive House has been sold in New Zealand, so the valuer from Prendos NZ that was engaged found it extremely difficult to source statistics to back up the benefits of a Passive House – namely lower bills, higher durability and a better & healthier quality of life; things that often take second fiddle to a big kitchen and shiny taps in the NZ market! Due to this the initial 3 bedroom/ 1 bathroom proposal was valued at $75k less than it would cost to build due to ‘market factors’.

 

After some speedy redesign to incorporate the additional bedroom and ensuite in the roof space, some further reductions on specification such as uPVC water tanks opposed to concrete, some amazing accommodations by Kane; and some items reverting to ‘client finish’; the valuer reassessed the project. After considering evidence for price increases from Green Star, eco homes and similar higher performing buildings in NZ and abroad, the final contract value came in at $502k – only $2k over the resulting valuation.

 

With the bank funding in place and the contract signed, the windows were ordered from abroad (due to them coming in at less than half sourcing them in NZ) and the SIPs were ordered from Formance. The project is due to start on site the first week of September 2020, with a completion date in early February 2021.

 

The project was intended to be Joe’s pathway to certification as a Passive House Designer, however delays caused by Covid meant that he is currently undertaking the Passive House Designer Course alongside the build.  After over a year of two steps forward and one step back at every stage, Joe & Sarah are pinching themselves that they’ve got this far, but are well aware that the bulk of the work is yet to come!

THE HEALTHY HOME DESIGN GUIDE

Project Type Single Residential Passive House Certified Home

 

Project Location Dates: Lower Saddle House Tahekeroa, Makarau 10/2018 – Ongoing (Scheduled completion Feb 2021)

 

Architect: Joseph Lyth

 

GFA: 100m2 Ground Floor 69m2 First Floor 56.5m2 Covered Deck

 

TFA: 122.3m2

 

Cladding Structure: Stained Board & Batten, Trapezoidal metal roofing

Formance SIPs – 115mm walls, 215mm roof

3604 suspended timber floor on piles. 2 x 115mm R2.9 Mammoth insulation

 

Windows: Bertrand timber/ aluminium triple glazed

 

Ventilation: Stiebel Eltron LWZ 180 Ducted HRV System

 

Hot Water: Stiebel Eltron WWK302H hot Water Heat Pump

 

 

Lower Saddle House is the future home of Architect Joseph Lyth, his wife, and two daughters.

 

The Lyths moved from the UK in 2016 and spent several years living in typical NZ code homes, with no designed in heating or ventilation, high energy bills, interior condensation & mould issues, and sleepless nights listening to their girls coughing every winter.

 

Like most people, they slowly built up a small deposit with which to buy a home, however they were loath to purchase an existing building due to their experience of existing homes, and Joe’s knowledge as an Architect of the failings of the current building code, and his experience of issues with existing housing through his work.

 

With some knowledge of Passive House Certification from his time in the UK, and after undertaking a Passive House Designer introduction course, Joe decided that a Passive House Certified home was the way to go, to provide a healthy home for his family to grow up in. Despite having a low deposit they managed to purchase a rural section 45 minutes north of Auckland with a 20% deposit, subject to an agreement with the bank that they’d begin building a property within 12 months. Subsequently, the deposit would be 10% of the overall land & build cost. Due to the low deposit, the bank stipulated that only a fixed price contract would be accepted, and that Joe (despite his role as a registered Architect) would not be permitted to project manage the build.

 

Construction in New Zealand is often prohibitively expensive, a factor that contributes to the low quality of our homes, as any increase in performance is often perceived to come along with high cost premiums. Joe and Sarah decided that they would be guinea pigs, and would use their project to show that you can build quality homes in NZ at more reasonable prices, by putting your money into the areas that count.

 

The philosophy behind the project is that it’s easier to upgrade your bathroom or kitchen than your windows or walls; so the majority of the budget is allocated to a high performance envelope, with the key aims being:

 

● High levels of insulation to minimise heat loss & gain through the envelope.

 

● High levels of airtightness to minimise heat loss through air leakage.

 

● High quality windows to allow light in while preventing too much solar gain.

 

● A heat recovery ventilation system, to retain heat while ensuring the quality of the interior environment.

The interior is simple and functional, with the interior finishes consisting of exposed painted SIPs, plywood walls and strandboard floors. This removed the cost of finishes from the project, while still allowing them to be applied at a later date. The bathrooms and kitchens too are simple, with basic fittings and finishes which can all be upgraded at a later date when budgets allow.

 

The form of the building is intentionally simple to keep costs down, and ensure a compact form factor to aid the buildings performance, with a carefully planned interior layout that provides generous spaces in a compact footprint. Initially the project consisted of a single storey with 3 bedrooms and one bathroom, with the structure designed to accommodate extending into the roof to provide a further bedroom and bathroom at a later date when costs permitted; however due to a low valuation, the end result was an open plan kitchen/ living/ dining space overlooked by a first floor snug area, 4 bedrooms, 1 bathroom with separate WC, 1 ensuite, several storage areas and a large laundry/ utility room all in 169m2 gross floor area.

 

As Passive House is relatively new in NZ the project has to navigate a fair few barriers. Despite sourcing a QS estimate, the initial pricing from a preferred contractor with Passive House experience came back at $780k - over double the initial $375k budget for the build. After a brief regroup, the project was put out to 4 different builders with a more in-depth description of the project aims and specification. Out of the 4, Kane Build Group came out on top due to their experience of SIPs and the quality of their work Joe had seen previously. The budget had had to grow, but luckily had been able to with the help of parents and a small inheritance, so the project proceeded to council consent.

 

Despite concerns due to the non-standard products, recessed window details, etc; the project flew through building consent, with the consenting officer exclaiming “I wish there were more projects like this!” and the only RFIs were querying the hot water system. With a builder and a building consent in place, the project approached the final hurdle – a valuation & approval from the bank.

 

Currently only one Passive House has been sold in New Zealand, so the valuer from Prendos NZ that was engaged found it extremely difficult to source statistics to back up the benefits of a Passive House – namely lower bills, higher durability and a better & healthier quality of life; things that often take second fiddle to a big kitchen and shiny taps in the NZ market! Due to this the initial 3 bedroom/ 1 bathroom proposal was valued at $75k less than it would cost to build due to ‘market factors’.

 

After some speedy redesign to incorporate the additional bedroom and ensuite in the roof space, some further reductions on specification such as uPVC water tanks opposed to concrete, some amazing accommodations by Kane; and some items reverting to ‘client finish’; the valuer reassessed the project. After considering evidence for price increases from Green Star, eco homes and similar higher performing buildings in NZ and abroad, the final contract value came in at $502k – only $2k over the resulting valuation.

 

With the bank funding in place and the contract signed, the windows were ordered from abroad (due to them coming in at less than half sourcing them in NZ) and the SIPs were ordered from Formance. The project is due to start on site the first week of September 2020, with a completion date in early February 2021.

 

The project was intended to be Joe’s pathway to certification as a Passive House Designer, however delays caused by Covid meant that he is currently undertaking the Passive House Designer Course alongside the build.  After over a year of two steps forward and one step back at every stage, Joe & Sarah are pinching themselves that they’ve got this far, but are well aware that the bulk of the work is yet to come!