Social skills - The A1 rapid build council homes that are sustainability all-rounders

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Building: Scheme of 12 x 85 sqm social houses Location: Dún Laoghaire, Dublin Completed: 2018 Budget: €2.57m (ex VAT) Standard: Nearly zero energy buildings (NZEBs)
Up to €155 per year for space & water heating (estimate, see ‘In Detail’ for more)

Dún Laoghaire-Rathdown County Council’s recent development of twelve social housing units at George’s Place in Dún Laoghaire is just around the corner from the waterfront. It also lies at the intersection of a long list of diverse objectives, some of which give every appearance of being contradictory.

The houses are rapid build yet sufficiently well-built to have achieved an A1 BER.

They are high-density yet each retains its own front door and avoids overlooking its neighbour. The site itself is a brownfield site and came with a list of conditions that had to be carefully negotiated before the first sod was turned. The design and build team, led by Dún Laoghaire-Rathdown’s architects department, manoeuvred their way through a maze of restrictions and criteria to deliver exemplar houses in record time.

Schools, healthcare, parks, shops, amenities and public transport are all close at hand.

Susan Corcoran and her two sons moved into their new home in George’s Place in June, just twenty-one months after the planning phase began. “We had a cottage in Dalkey that was over a hundred years old,” says Corcoran. “You walked in the front door and you were in the main living areas. It was cold and it was drafty.”

“What I love about our new home is that as well as being warm, there are no drafts.” She also loves the fact that despite the fact that it is a relatively compact two-bedroom unit, her house feels bigger. “The windows are huge,” she says, “we get brilliant light.”

The best thing about her house, however, is the location. Everything is a walk away. Bob Hannan, senior architect with Dún Laoghaire-Rathdown County Council explains that a variety of factors led to the designation of the George’s Place site for social housing.

“One of the high-level themes of the Dún Laoghaire-Rathdown urban framework plan centres on connecting the town centre to the waterfront. Dún Laoghaire has that dichotomy between a main street which has underperformed and a waterfront which is buzzing with people. One of our strategies is to create as many links as possible between the two.”

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A second ‘high-level theme’ in the plan promotes the idea that increasing the residential population of the town is the best way to boost its vitality and economic performance.

With these themes guiding developments in the area since 2004, individual site strategies were drawn up to unlock their potential, while remaining within the parameters of the framework plan.

The next challenge was to find a way to deliver own-door, high-density urban dwellings in keeping with the character of the area. Bob Hannan puts it like this: “If you’re going to create family housing, how are you going to do it in the most efficient way possible using precious urban land?”

The shallow, railed-front gardens so prevalent in the area offered a neat example of how to limit each house’s external footprint, as did the small courtyard back garden. Splayed windows at the first floor also minimise direct overlooking of neighbours.

Surprisingly, each house even manages to get its own car-parking space, and there are what the architects describe as ‘home zones’ – informal play and amenity areas – which are passively overlooked by the houses themselves.

Hannan says that while the houses were still in the planning stage, the local authority received an invitation from the government to submit developments to its rapid delivery programme. George’s Place became the council’s response to that call.

Planning permission for the twelve houses was submitted to the local authority’s internal planning process in September 2016. The project went out to tender the following February and contracts were signed in October 2017. Susan Corcoran and her family, along with all of the other tenants, moved in last June.

“We wanted to unravel the idea that rapid build is lower quality,” says Hannan, explaining that the decision was taken to move large elements of the construction offsite not alone to speed things up but also to ensure higher standards.

“With a traditional build, you’d have a guy on a wet November night trying to cut insulation. It’s dark and raining, and he’s freezing. It’s very hard to keep high quality in something like that."

Increasing the residential population of the town is the best way to boost its vitality.

Manufacturing in factory conditions, by contrast, ticks two boxes – speed and quality. To further facilitate offsite construction, the designs of the two types of houses deployed were kept simple. Both are two-bedroom; one narrow fronted with double aspect front and back, the other a wide-fronted shallow unit. To the same end, the design team restricted itself to a small palette of good quality, robust and easily maintained construction materials.

Though rapid build methods may be comparatively new to the construction industry, at George’s Place they were delivered by Sisk Living, a new division of John Sisk & Son – one the oldest and most trusted builders in Ireland.

1 Two courses of Quinn Lite AAC blocks used in subfloors at perimeters and party walls to reduce thermal bridges; 2 the ground floor also features 150mm XT Xtratherm insulation and a radon control membrane; 3 panels being lifted into place for the timber frame structure; 4, 5 & 6 the Kingspan Century Ultima wall system takes only between three and four days to erect once it arrives onsite, and delivers high levels of thermal performance and airtightness; 7 Airtight Pro SCL membrane on the internal side of ceiling; 8 Kingspan PIR insulation to the inside of the roof construction; 9 windows & doors in place, and work begins on fitting the external brickwork over a Protect TF200 Thermo breather membrane.

John Sisk & Son CEO Stephen Bowcott spoke to Passive House Plus about the company’s motivation: “For generations Sisk have been at the centre of house building in Ireland and particularly at times of social need. With the onset of the housing crisis and in support of Rebuilding Ireland, we set up Sisk Living as a specialist residential building division with a clear vision: to become the premier house building contractor in Ireland in terms of size, speed and quality with the lowest possible cost to the end user. George’s Place was one of our earliest projects and we are very proud of our achievement in delivering it.”

According to Sisk Living director of housing, Norman Higgins, the project was a perfect fit for them. “With near zero energy building (NZEB) soon becoming mandatory for all new housing stock, we wanted to test ourselves to deliver this standard as early as possible. George’s Place was a very attractive proposition for us, not only because of the NZEB factor, but also because it was an extremely fast build on a technically challenging city centre site which allowed us to bring our expertise to bear.”

It may sound contradictory but while this was a busy city centre location, it was also, a quiet and thriving residential area. Poor relationships can develop quite quickly between a very busy contractor and neighbours in a location such as this. Managing this aspect of construction was about the smaller things like keeping neighbours informed of what was happening and reacting to any query promptly and respectfully.

One significant sustainability initiative that Sisk Living brought to the project was to register it with the Irish Green Building Council’s (IGBC), Home Performance Index (HPI). Sisk Living then made continuous submissions to HPI through construction and last May, George’s Place was awarded a silver certification under the exacting scheme. The HPI label was developed by the IGBC to encourage excellence in the development of new homes. In addition to the sustainability of a dwelling, HPI assesses its impacts on wellbeing and the costs associated with living in these homes. Drilling down through the HPI documentation, you uncover some interesting results. For example: George’s Place received the highest ever score for ‘walkability’. Schools, healthcare, parks, shops, amenities and public transport are all close at hand, reducing car dependency and boosting the health and financial wellbeing of those who live there.

Dún Laoghaire-Rathdown County Council architects appointed A2 Architects as ‘enabling architects’ to undertake the detailed tender package after planning had been approved and to manage the project during the construction phase.

Peter Carroll of A2 says that the site itself was very challenging.

“You wouldn’t think that it would lend itself to rapid delivery construction,” he says. “We had difficulties with Japanese knotweed, there were more than a dozen boundary conditions, and we had to deal with existing buildings onsite that had to be remediated to hold onto their integrity.”

The build team also had to take into account the fact that they were surrounded by busy roads, and that the site lay at the centre of a thriving residential area.

“We had to ensure that our tender drawings and detailed design were as accurate as possible, and as specific as possible. This was a government contract that didn’t allow any slack.”

Everything, from the pressings of the sills to the ridge details, railings and hard landscaping were closely specified by A2 in collaboration with Dún Laoghaire-Rathdown architects well in advance. Having said that, Carroll notes that a number of tolerances were built into the tender to allow participating parties to suggest rapid delivery systems. Sisk Living selected the Kingspan Century Homes rapid build timber frame system, which takes between three and four days to erect once it arrives onsite.

It was originally envisaged that the houses would be certified passive, and while they don’t quite meet certification thresholds, passive principles are embedded in the design.

What I love about our new home is that as well as being warm, there are no drafts.

As Bob Hannan asserts, Dún Laoghaire- Rathdown is one of the most progressive local authorities in the country when it comes to energy standards.

“It may not be certified but it does have fabric-first principles – very high levels of insulation and airtightness, combined with mechanical heat recovery ventilation. The development is an exemplar in terms of pushing high performance building to its limit, and that is driven by the council itself, and our department in particular.”

For the record, air permeability tests report values of between 1.24 and 3.2 m3/hr/ m2 at 50 Pa, with all bar two units clocking scores of under 2.0 – while U-values are within passive house ranges, as are thermal bridging details. The units also blitzes Ireland’s new nearly zero energy building standard (NZEB), which only came into force at the start of this year.

Peter Carroll says that during the tendering process, the passive house strategy was retained in order to attract like-minded contractors who would not be intimated by exacting standards. And that explains how the development secured such a high score in the Irish Green Building Council’s HPI scheme.

The fact that these houses were built for €249,000 (incl. VAT) each also gives the lie to the idea that a fabric-first, low energy build is an expensive build. And because each house carries an A1 BER, running costs for the tenants should not exceed €200 per year. Susan Corcoran points out that because we’ve had such a mild winter – so far at least – her house has not been seriously tested by the elements. Indoor air temperature over the last eight months has remained steady, warm and comfortable. She likes the fact that she has constant hot water, that yearly maintenance of the system is built into her rent and that the controls for the Nilan Compact P combined heat pump and ventilation system are so easy to use.

“It’s a touch screen with an up and a down arrow,” she says. “Couldn’t be easier.”