Delivering Cost Effective Passive House in Ireland

I no longer feel the need to loudly extol the virtues of Passivhaus. Whilst they are far-reaching in terms of energy, health and comfort, these are not the factors that make the sale for budget-driven projects. The question on the lips of those holding the purse strings is “what does it cost?”. This is the case for any project, Passivhaus or not.

The workshop, Delivering Cost Effective Passive House in Ireland, presented the opportunity to reconcile sustainable solutions with the realities of a capitalist industry.

A diverse range of speakers promoted Passivhaus as a cost-effective solution at the workshop held in August 2016 and organised by Ireland’s Passive House Academy. To repeat the pun used by Tony Bamford, Planning Consultant at Bamford and Bonner:

“Passive House makes perfect ‘cents’ for Ireland.”

– Tony Bamford

Representatives from two Contractor-Developer firms gave their insights at the workshop: Seamus Mullins who is a Quantity Surveyor at Michael Bennett Group and Patrick Durkan of Durkan Residential. They each have their own approach to ensuring that they can successfully build a Passivhaus with zero net additional cost.

“I firmly believe that the next generation of housing will be Passivhaus.”

– Seamus Mullins

Mullins emphasised the speed and efficiency borne out of building to the Passivhaus standard, citing a 12-week build duration for the construction of a pair of semi-detached houses. The construction techniques used result in minimal embedded moisture and the quality control of Passivhaus Certification results in very few snags upon completion. The faster turnaround minimises cash exposure, which consequently, reduces risk. Lower risk = lower cost.

Mullins advised that knowledge is essential in ensuring that Passivhaus projects can be delivered to budget. Staff should be trained up with at least one Certified Passivhaus Designer and a couple of Certified Passivhaus Tradespeople on each project. The knowledge should then transfer to the homeowners through a user-friendly operator manual. Michael Bennett Group has found that this formula has increased the client satisfaction ratings of their homes.

“Relying on renewable technology alone to meet energy standards is like putting Ferrari wheels on a Mini”

– Patrick Durkan

Patrick, Kevin and Barry, the Durkan brothers, run Durkan Residential. They believe that Passivhaus should be available to the masses. The houses they build are for first-time buyers and consequently, their primary question tends to be: is this affordable?

Durkan Residential invested in creating a set of standard thermal bridge free details, along with their corresponding calculations. This means that they are now able to guarantee the thermal integrity of all future builds without additional expense. By getting this crucial factor right, they have eliminated the need for gas mains and radiators. This lowers the cost of utility connections and eliminates the need for distribution pipes for the heating system. The ventilation and hot water demand can all be managed with one fridge-sized unit per property: Nilan Compact P. This product provides the ventilation, heat recovery and domestic hot water.

Whilst recognising the ethical benefits of Passivhaus, neither Michael Bennett Group nor Durkan Residential could utilise the standard for affordable homes unless the margins were favourable. This is a key factor to acknowledge for Passivhaus to be fully available to the masses. This workshop went a long way to encourage a frank dialogue about real-world methods of delivering cost-effective Passivhaus homes. We must now continue the conversation so that we can improve the accessibility of sustainable design, making it a viable option no matter the budget.

Signage on a Durkan Residential construction site: “Built it Tight, Ventilate it Right”