Project: Knockrabo, Mt. Anville Road
Developer: Maplewood Residential
Contract Start Date: May 2016
Contract End Date: December 2018
Contract Location: Goatstown, Co. Dublin
No: of Housing Units: 50 houses

Knockrabo is an exceptional new development of 3, 4 & 5 bedroom houses and 1, 2 & 3 bedroom apartments and penthouses positioned on a stunning elevated site with views of the sea and the city. Knockrabo has a rich heritage. It is built on the site of Mountanville House, a demesne that was the home of Henry Roe who is famous for having paid for the restoration of Christchurch Cathedral.

The name Mountanville House was later changed to Knockrabo. The attractive house of Knockrabo, which stood opposite Mount Anville Convent, was a Victorian house of exceptional quality being located on high ground overlooking much of South County Dublin and a rooftop belvedere was added in the 19th Century to take advantage of these views.

Design Team

Architect: O’Mahony Pike Architects
Structural Engineer: DBFL Consulting Engineers
Civil Engineer: DBFL Consulting Engineers
M&E Consultant: O’Connor Sutton Cronin (OCSC) Consulting Engineers
Landscape Architect: Dermot Foley & Associates
Main Contractor: Capami Construction Ltd

PKOB Duties

Attend design team meetings, Provide advice on efficient Part L compliance, Value Engineer proposals, Prepare Order of Magnitude Costs, Preparation of Bill of Quantities, Dispatch tender documents, Report on tenders received, Draw up contracts for signing, Attend monthly progress meetings, Check monthly payment applications, Issue Recommendations for Payment, Check and agree all variations and additional works, Issue Cost Update Reports, Agreement of Final Account with various sub-contractors.

Abnormal Site Conditions

Due to the location and exclusivity of this site the apartment design is of a very high standard. The Architects have designed a façade with brick, aluminium curtain walling to match in with existing buildings in the surrounding areas. The balconies also contain glazed balustrades. The internal specification and finish will also be of a very high standard in order to compete with neighbouring developments.

The main cost driver in terms of abnormal costs associated with this development are the existing ground conditions. We are currently carrying out a site investigation report consisting of trail holes and boring probes to ascertain the content of the sub-soil. Initial reports have shown the presence of solid rock at depths as shallow as 300mm below existing ground level.

The drainage works are fully designed and the main drainage trenches are deep and vary between 2.00 – 3.00m. This will require heavy machinery and slow progress in breaking out this rock.

The lands were previously used as a sports complex and an area to the rear of the site contains made ground. Samples of this made ground have been sent to be for tested for contamination. We would envisage at a minimum that this made ground will need to be excavated and removed off site under licence and replaced with acceptable material.

There are a number of specimen trees on-site and the services of an arborist have been acquired for advice on how to route the drainage works to outfalls in the neighbouring Ardilea Downs. It has been agreed that microbore tunnelling will be required through solid granite to protect the roots and specimen trees. There is approx. 150m of tunnelling required for both the foul and the surface water drainage. The services of an ecologist have also been acquired and a full report has been carried out on the site. This report has highlighted the presence of Japanese Knotweed throughout the construction zone. The eradication of this Japanese Knotweed is a condition of the planning and will be carried out by a specialist contractor with experience in this area.

Due to the historical nature of the site a conservation architect has been employed to oversee and implement a safe sequence of conservation work to the various structures. One of these structures is an existing stone wall that bounds the site. Exploratory work will need to be carried out to enable the Engineers to design protective works to these structures. We would also envisage that temporary sheet piling and shoring works will be required prior to any construction works to safeguard any protected structures. There is also a steep gradient across the site which also requires stepped foundations and step details to roofs and retaining walls etc. The site gradient impacts the drainage works, footpaths, roads and driveways with retaining wall structures required to provide level access to houses.

There is also significant off-site development works with approx. 885 meters of a new 450mm diameter foul sewer to be installed within the existing road carriage on Roebuck Road. A new watermain is also to be installed along Mount Anville Road. We would consider all of the above conditions to be abnormal and are usually not encountered on many sites and certainly not all on one site. The site development works costs on this site will be well in excess on any benchmark green field site.

Additional Information

If you require more information on any of our services please do not hesitate to call us on 01 424 2168 or email

Some of Our Happy Clients


Close & Lasting Relationships