Features

Where award-winning Passive House architecture begins at home

27 Mar , 2023  

Passionate about sustainability, Peter Nickels is a Dublin-based, award-winning Passive House architect who creates sustainable, comfortable, healthy and beautiful places to live and work. Peter has brought his expertise to bear on a magnificent portfolio of projects across the capital, including a stunning deep retrofit on his own home / workspace – The Willows in Dublin 6.

As a certified Passive House designer, Peter Nickels is passionate about the benefits that designing and building to the Passive House standard can bring to individual homeowners and building users, to society as a whole, and to the environment.

Indeed, he lives and works in a multi-award-winning Passive House building that he designed for himself and his family in Dartry, leading by example and encouraging clients and others to embrace Passive House standard for themselves.

In 2022, The Willows was awarded the prestigious RIAI Architecture Award for Sustainability as well as the NetZero Ireland Construction Award for Retrofit. This inspirational, innovative and ground-breaking project was also shortlisted in the Climate Action & Sustainability category at the Property Industry Excellence Awards 2022.

For this comprehensive Passive House deep retrofit and extension, an existing two-storey house with a flat roof, built in 1972, was transformed beyond recognition by the addition of a third storey on top to create a spacious, striking 2,950 sq. ft., five-bedroom family home with large home office.

The entire house was refurbished to EnerPHit standard (the Passive House Institute standard for existing buildings), which is the highest standard of energy efficient construction. The whole envelop of the extended and refurbished building was wrapped in external insulation, with the shape of the roof creating a flat roof along the ridge, facing south, to ensure maximum efficiency of the roof-mounted solar photovoltaic panels.

The house has been reimagined as a modern, contemporary interpretation of the Victorian suburban villa, responding sensitively to the scale and context of neighbouring historic protected structures, whilst embodying Passive House design principles. The floor area of the original house has been increased by more than 50%, yet – due to a fabric first approach.- the overall energy consumption of the building decreased by an incredible 74%.

Boasting over thirty years’ professional experience working in the UK, Hong Kong and Ireland, Peter established Peter Nickels Architects to focus on high quality, high performance, sustainable residential projects. He believes that the choices we make when designing and refurbishing our houses have far-reaching consequences – for our quality of life, for our physical and mental wellbeing, and also for our planet.

Placing enormous stock on the importance of sustainability and performance, he is cognisant of the fact that The Willows – where he was in the unique position of doubling up as both architect and client – is a landmark project not just as a model Passive House property in Ireland but also within his own portfolio:

“It was the first fully-completed Passive House project I’ve done and once you have that learning on board you are then able to take on future projects. Once you’ve gone out and completed a Passive House project, you can’t unlearn it. We will now approach all future projects using these same standards.”

Peter Nickels Architects specialise in designing comfortable, healthy, low energy new build residential projects to the Passive House standard and whole house, holistic refurbishment/ retrofit projects to the EnerPHit standard, consistently creating bespoke design solutions that are tailored to each particular client / building to deliver contemporary design using high quality, beautiful materials and simple, robust details that will age well

Prior to setting up his own firm, Peter worked on largescale projects for large architectural practices, including Gilroy McMahon. “Once I went out on my own, I went back to doing smaller scale residential projects and you come to realise that this is the real coalface of where you need to be in terms of sustainability; upgrading the performance of the existing housing stock is a real issue.

“This project was a landmark deep retrofit project to Passive House standard, successfully delivered, which proves it can be done. I had all my Passive House training done but the last piece of the jigsaw was to actually complete a project to this standard. Passive House is the highest standard in terms of building performance and it wouldn’t make sense for us to aim for anything less than this now. Going forward, we will be aiming for Passive House on all future projects.”

In an ideal world, it would be fantastic to retrofit every existing property to Passive House standard, but this of course will not be possible: “Every property is different and you have to look at each on its own individual merits,” Peter states. “There are of course a lot of building types where Passive House would be very difficult to achieve, such as historic buildings, for example.

“And it’s not just down to the age of the property – it will also depend on the configuration of the building. It’s a very invasive process, with a lot of the work going right back to the very shell of the original building in some cases. Generally, it’s going to be more viable on modern structures. As this [The Willows] was a 1970s building, it was a lot more achievable in terms of what we needed to do.”

For the extension and retrofit of The Willows, Peter and his wife – both of whom work from home – and their four teenage children needed an additional bedroom, a home office, storage space, and to allow for potential future ground floor living. In addition, the thermal performance of the house had to be completely upgraded.

The original house was one of a pair of identical infill houses, which were completely out of scale and character with their surrounding context of three-storey Victorian redbrick villas.

Whilst it might well have been quicker and easier to demolish the house and start again, it was decided instead to retain the existing structure as far as was practical, working with it, modifying and upgrading it. This approach is far more sustainable and minimised the impact of embodied carbon emissions.

Additional space was created by extending upwards instead of outwards. A new second floor was added over the original flat roof, providing a spacious home office on the southern side (with views out to the surrounding trees and the Dublin mountains) and a master bedroom suite. This design solution provided the space required within the same footprint, without extending any closer to surrounding boundaries, and brought the house into scale with the neighbouring three-storey Victorian houses and 1990s townhouses.

At ground floor, the kitchen and living room were swapped – the kitchen was relocated to the brighter, southern side of the house whilst the living room was moved to the north / west side, where it would be bright in the evening. The kitchen, with full height glazing on two sides, feels like it is actually part of the garden and the movement of the sun throughout the day can be fully experienced here.

In addition to the new extension, the whole house was refurbished and upgraded to achieve the EnerPHit standard – the Passive House Institute standard for existing buildings and the highest standard of energy efficient construction. The decision to extend upwards on the existing footprint increased the building’s form factor (the ratio of external perimeter to internal volume) to 1.16, greatly improving the efficiency of the thermal envelope.

The main emphasis of the upgrade works was placed on the fabric first approach, i.e., high quality windows and doors, high levels of insulation and airtightness measures. These elements will ensure the ongoing high performance and low energy costs of the house well into the future, representing real value for money.

Furthermore, as the thermal performance of the envelope is so effective, there is no requirement for a central heating system, so the savings were offset against the costs of the high specification building fabric. The existing masonry shell, plus the new lightweight blockwork extension, were fully wrapped in external insulation to ensure very low U-values and limiting thermal bridging to a minimum.

Passive House standard triple glazed windows were designed to maximise the amount of glass and minimise the frame, for thermal efficiency, resulting in large, single pane windows which are deep set into the external insulation layer to limit thermal bridges

The end result is a completely unique, contemporary, future-proofed, ultra-low energy house that sits comfortably within an established, sensitive and historic setting, and is a beautiful, comfortable and healthy place to live and work.

Peter Nickels Architects,

The Willows,

Sunbury Gardens,

Dartry,

Dublin 6

Tel: 086 3158902

Email: [email protected]

This article was published in Building Ireland Magazine, March 2023, Vol 9 No 3