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Tas Approved

Retaining Walls

Roads Service N.I. Approval of retaining walls.

The Roads Service in Northern Ireland requires that all proposed retaining walls within 6m of a road boundary or which support a public road are subject to Technical Approval. The webpage below gives details of this procedure:

Roads Service Northern Ireland Technical Approvals

It is important that all developers and contractors make themselves aware of these requirements especially if they want the roads within their development to be adopted by Roads Service. There are many specialist and traditional systems that are not accepted by Roads Service. This can create serious problems when trying to finalise contractual arrangements for selling houses or retrieving road bonds.

Please be aware that even acceptable systems can take six months to a year for approval to be achieved. It is recommended that retaining walls are not started unless approval has been obtained. Even if you are using an approved system it is important to satisfy Roads Service with regard to your proposals for Vehicle Barriers above and below the retaining wall, pedestrian restraints above the wall and consent to discharge from any drains behind the wall.

Based on previous successful applications, the following guidance shows which Acheson & Glover blocks can be used but this should not be seen as a definitive guide to future approvals:

i). Walls up to 1.0m high - Approval not required
ii). Walls up to 1.5m high -BBA Anchor Vertica and Anchor Landmark Systems have been accepted.
iii). Walls up to 4.0m high (not directly retaining road) - Vertica has been approved on all applications to date as a departure from standard. Landmark is also acceptable but Diamond is definitely not acceptable.
iv). Walls up to 4.0m high directly retaining road - Only Landmark blocks have been approved in these walls.

Anchor Diamond does not carry any independent accreditation
Anchor Vertica carries a standard BBA Certificate
Landmark carries a Roads & Bridges BBA Certificate
As such only Landmark blocks can be used in retaining walls over 1.5m high requiring Technical Approval without a departure from standard.

Achieving technical approval from the Roads Service can be a long process and we recommend that you talk to a consulting engineer regarding this issue. Acheson & Glover have a comprehensive technical consultancy team which includes fully qualified engineers, who can help you with this issue. Contact us for further information.