Rachael O'Hagan > The Chambers of Alexander Nissen KC > London, England > Lawyer Profile

The Chambers of Alexander Nissen KC
Keating Chambers
Rachael O'Hagan photo


Recently described as: ”an extremely bright and effective advocate, and a real hit with clients”; “very intellectual, she gets to the heart of a dispute quickly and is very engaging”; and an “unflappable” barrister “who understands the issues straightaway”. Rachael specialises in high-value construction, engineering, technology, infrastructure, nuclear/energy along with professional negligence and insurance claims related to these sectors. She also acts in procurement disputes. She is instructed as a junior and in her own right, including acting as sole advocate in international arbitrations. Her clients are domestic and international, and she has experience in the English Courts and also representing parties under various international arbitral rules, including: ICC, LCIA, DIFC-LCIA, UNCITRAL and DIAC.

Rachael is recommended in leading UK and Global directories, including for her work in construction, professional negligence and international arbitration. She was nominated for International Arbitration Junior of the year at the 2019 Legal 500 UK Awards. She is recognised as a Future Leader in the WWL Global Guide.

Rachael advises clients on all forms of commercial dispute resolution and has represented clients in mediations (including under the Court Scheme), adjudications and disputes under the Railway Industry Dispute Rules. She has been appointed as the legal nominee on a Dispute Advisory Board and is also a TECBAR Adjudicator. Rachael has also represented a Corporate Core Participant as part of the Grenfell Inquiry.

Rachael has contributed to various construction legal texts, including: two chapters of Keating on Construction Contracts (11th Edition); and writing a Chapter for “Construction Law, Costs and Contemporary Developments: Drawing the Threads Together – A Festschrift for Lord Justice Jackson”, Edited by Julian Bailey.


TECBAR Adjudicator 2020
TECBAR Committee Member – (ongoing appointment)
Keating Chambers, Barrister 2019 –
39 Essex Street, Barrister 2009 – 2019
Called to the Bar 2006




Society of Construction Law


Bar Vocational Course, Nottingham Law School (Very Competent): 2005-2006
LLB, Law with French, Birmingham University (2.1 (Hons)): 2001-2005
Diplôme d’Etudes Juridiques Françaises, L’Université de Limoges: 2003-2004

Lawyer Rankings

London Bar > Construction

(Leading Juniors)Ranked: Tier 2

Rachael O’Hagan – Keating Chambers ‘Rachael is incredibly hardworking and has a great mind to get to the heart of the dispute. She is a real team player, gets to grips with detail quickly, and is good on her feet. Her approach is always commercial and practical.’

Known as a ‘go-to set for construction disputes’, Keating Chambers regularly act on complex disputes both domestically and internationally. Piers Stansfield KC and Rachael O’Hagan are representing Cundall on Standard Life v Gleeds, a matter relating to a multi-million pound professional negligence claim against the architects and engineers a large mixed-use development. Numerous members of chambers are instructed in Martlet v Mulalley, which will be the first post-Grenfell cladding case to reach trial and relates to whether the requirements of the building regulations have changed, including Simon Hughes KC and James Frampton for the defendants, and Jonathan Selby KC and Tom Coulson for the claimants. David Thomas KC and Matthew Finn are acting on Walter Lilly v Clin, representing the claimant on a case which has industry-wide implications for the construction and planning sectors in relation to building demolition. Vincent Moran KC leads a number of members from the set on Northumbria Healthcare NHS v Lendlease, a large multi-party dispute concerning widespread defects in relation to the construction of a new specialist emergency hospital, acting for Lendlease as the defendant. Keating also continue to be involved in Grenfell Tower Inquiry Phase 2, with Adrian Williamson KC, Abdul Jinadu and Emma Healiss all acting for the bereaved, survivors and former residents as construction counsel. Calum Lamont KC took silk in February 2022, and Alexandra Bodnar has recently joined from 39 Essex Chambers.

London Bar > Professional negligence

(Leading Juniors)Ranked: Tier 6

Rachael O’HaganKeating Chambers

London Bar > International arbitration: counsel

(Leading Juniors)Ranked: Tier 3

Rachael O’HaganKeating Chambers ‘Rachael is incredibly easy work with. She integrates fully into the legal team, and combines a sharp mind with excellent inter-personal skills. She is good on her feet, and excellent at building relationships with Tribunals.’

London Bar > Public procurement

(Leading Juniors)Ranked: Tier 3

Rachael O’Hagan – Keating Chambers

Keating chambers assists government bodies with both contentious and non-contentious work, and has been at the forefront of the development of procurement law. Keating Chambers is commended as ‘a chambers that has a number of excellent advocates in the field‘ including Sarah Hannaford KC who is acting for HS2 Limited in Siemens v HS2, a case revolving around the award of the contract for rolling stock used for HS2. Versatile silk Fionnuala McCredie KC regularly acts for interested parties in litigation, as does Rachael O’Hagan who since joining the set in 2019 has been involved in extremely high-profile procurement challenges as senior junior.