HPH297 : Why retrofit a Victorian terraced home to Passivhaus standard? – with Guy Hargreaves

Guy Hargreaves explains why he wanted to renovate his Victorian terraced house to Passivhaus standard and how this is going to be achieved.

Interview with Guy Hargreaves

Guy Hargreaves is originally from New Zealand, but he met his wife Susan in Australia.

While living in Sydney they bought and renovated a Federation style house in which to bring up the family. When the children were in their early teens, they relocated to Hong Kong with Guy's work. And after 11 years there, they followed their children to the UK (where they had gone to university and settled).

As Susan was doing a masters in Oxford that became the obvious place to set up home and in October 2019 they bought a Victorian terraced house. Initially they planned to live in the house for a couple of years to get a feel for it, but it quickly became clear that it would need a lot of work to make it liveable. So they started planning a renovation straight away.

The building is set over four floors and includes a self-contained basement flat and converted loft.

A visit to the National Self Build and Renovation Centre was a great starting point

While Guy and Susan were able to lean on the experience of their previous renovation, they were keen to upgrade this property to be a high performance home.

After seeing several Passivhaus homes on Grand Designs over the years they had become interested in the concept, but it was a visit the National Self Build and Renovation Centre (NSBRC) that acted as a catalyst for targeting Passivhaus standard. This is also where they met Alan Budden from Eco Design Consultants, who they would later hire as the project's architects.

Having studied mechanical engineering at university, Guy felt that discovering the Passivhaus standard was a bit of a homecoming.

“The Passivhaus concept itself really grabbed my imagination, to be honest, and I was hooked.”

Working remotely caused minimal delays

Having gained planning consent (in January 2020) with help from a more ‘traditional' architect, Guy realised that they needed a specialist for the Passivhaus refurbishment. So they hired Eco Design Consultants to take over the project.

This coincided with the beginning of the global pandemic and consequently the project was progressed during lockdown.

Despite this challenge Guy believes it made little impact on the project's timeline.

Preserving the ‘period' feel is important

As part of a three terrace development, Guy was keen to keep the heritage feel of the property at the front.

“We don't want to replace Victorian sash windows with anything that doesn't look like the Victorian sash windows that are there now.”

The rear of the building is less important because most houses have been extended over the years and they all look different.

Passion is a driver for targeting the Passivhaus

This renovation will be to Passivhaus standard rather than the slightly less stringent retrofit standard, EnerPHit.

Guy is hoping that it's not going to be a much heavier lift.

“It's the passion I have for the Passivhaus certification more than anything. I'm not sure that the internal feel of the property will be much different if it was renovated to EnerPHit certification.”

There are different insulation strategies for different elements of the building

The historic brick facade will remain at the front and back, but it will be insulated internally.

At the back of the house the ground floor will be dug out and a new concrete slab will be set on top of insulation.

In the basement, the top of the floor will be taken off and a Diathonite screed will be laid down.

Interestingly, the party walls will not be insulated at all.

The windows need to be replaced

All windows and doors need to be high performance, so these will be upgraded to triple-glazed products.

The whole building will also be ‘wrapped' internally for airtightness layer. This layer will come in the form of various materials.

‘Futureproofing' the building justifies the cost

Guy admits that there are significant costs attached to a renovation of this quality and performance.

However, he bought at a price that reflected that the property needed a full renovation. Also, part of retrofitting this home is to futureproof it against the impact of climate change and rising energy costs.

On top of that, there is no doubt that the comfort levels of the house will be vastly improved and this too, along with Passivhaus certification, may be reflected in what the property will be worth in future.

Their builder was keen to develop skills

Finding a builder with Passivhaus experience was really hard.

So Guy has hired a firm who have considerable renovation experience but also demonstrated a desire to tackle a project of this nature.

PHPP adds another dimension to the project

In addition to balancing cost, quality and speed, Guy says you must always think about performance.

“You're always trying to balance what you want to do stylistically with what the PHPP model will let you do! So that becomes a fourth dimension. Everything you do has an impact in terms of, will the building perform the way you want it to perform?”

Find out more

Visit the website of Eco Design Consultants

Follow Eco Design Consultants on Twitter

Transcript

National Self Build and Renovation Centre

Guy and Susan started their renovation journey at the UK's only permanent exhibition centre for self-builders and renovators – the National Self Build & Renovation Centre.

Located just outside Swindon it's a one-stop shop for learning about the build process and sourcing potential suppliers.

They also offer a range of courses and workshops. Find out more by visiting their website.

A tour of Carrstone Passivhaus Plus project

Eco Design Consultants were also behind Carrstone Passivhaus.

Check out this video tour for more information about the house and its design.

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