Rockbrook Apartments, Dublin

Around 11,000m² of Wraptite® – the Proctor Group’s external air barrier membrane – are being installed at Rockbrook Apartments in Sandyford, Dublin. The 428 apartments, built in two blocks and arranged around two courtyards, are all being certified to the Home Performance Index (HPI).

HPI certification includes enhanced levels of airtightness, as part of the overall aim “to produce great quality homes, healthy and comfortable, with efficient use of resources, minimising waste and destruction of the environment.”

Readers outside Ireland are unlikely to be familiar with HPI certification. Essentially, it is a residential equivalent to BREEAM or LEED. First trialled in 2016, the scheme is managed by the Irish Green Building Council.

Demand for the certification has grown in the years since and, according to the HPI website, many developers use the certification as “a symbol of quality assurance” in their developments. In part, that is because one of the five core categories assessed for HPI certification is quality assurance – alongside environment, health and wellbeing, economic, and sustainable location.

For areas of the scheme considered to be most important, mandatory requirements are set to ensure a particular level of quality and comfort is achieved. Examples of such areas include water efficiency, ventilation and thermal bridging, as well as the aforementioned enhanced airtightness.

It is in this context that Wraptite has been specified and, at the time of writing, is currently being installed.

Rockbrook Apartments features a concrete frame with SFS infill stud. The Wraptite membrane, which is both airtight and vapour permeable, is applied to the external face of the wall structure. In this position, the airtightness barrier is moved away from the internal services zone, which simplifies detailing and reduces the number of penetrations.

At the same time, Wraptite’s vapour permeability allows the passage of moisture vapour and helps to eliminate any condensation risk in the wall.

Wraptite has always been a feature of the facade specification at Rockbrook Apartments – and it was originally complemented by an internal membrane acting as a vapour control layer (VCL).

“There was a bit of to-ing and fro-ing about the need for both membranes,” says Gerard Butcher, Contracts Manager at Comer Group Ireland. “Because of how Wraptite performs, we could remove the VCL and save the time and cost of fitting two different membranes.”

Comer Group Ireland is the main contractor and developer, and this project represents their first time working with Wraptite. The apartments feature a lot of detailing, whether that is returning the membrane into window and door openings, sealing the ‘letterboxes’ where M&E services enter the building, or dealing with the external walkway terraces that are a feature of the design. Even with all that detailing, the installation work by specialist contractors BAMCO is progressing well.

Initial airtightness results have been very good as testing has been carried out on the first completed apartments. “It’s a matter of making sure everything is insulated and sealed,” Gerard explains. “The Wraptite is very, very good, and we’ve just got to make sure we keep on top of everything.”

The Proctor Group has been on hand to support the project from the beginning. Regional Sales Manager Tony Ruth has visited site multiple times, and Gerard is complimentary about the benefits of such comprehensive support.

“Tony is very good and very enthusiastic. We had a few detailing issues at the start but he really helped with getting technical information to us.” As a result, the project got off on the right foot and is on track to deliver the performance needed for the HPI certification.