"Jonathan is very business-minded and pays great attention to the changes in the market. He continually and diligently provides support and is very responsive." He "is hugely experienced and takes good points. He's a wise and authoritative voice." He's also "a confident, slick lawyer who is a hard fight on the other side!"
Chambers UK 2023


Jonathan Hosie is a partner in the Construction & Engineering group, who focuses on the management of risks under construction and engineering contracts. He provides clients with both transactional and dispute management support. His transactional work involves front-end procurement and drafting advice on project documentation, with an emphasis on EPC and complex construction contracts as well as joint ventures. He combines this with considerable experience in claims and dispute management. Jonathan’s experience spans a diverse range of projects, including power plants (nuclear, conventional and renewables), upstream, mid-stream and downstream oil and gas projects, petrochemical complexes (new build and expansion schemes), mining developments and infrastructure (roads, bridges, tunnels, rail and utilities), as well as city centre office developments, hospitals, schools and residential developments. As part of his commitment to the industry, Jonathan served on the Council of the Society of Construction Law for more than 10 years and chaired a number of industry working groups, including within the Design Build Foundation (now Constructing Excellence) and for the Joint Contracts Tribunal on the development of a multi-disciplinary form of appointment.

Jonathan has extensive international experience, having worked on projects in a significant number of jurisdictions across Africa, Central and South America, as well as Russia, Scandinavia, Switzerland, Eastern Europe, the Middle East, India and the Far East. In these matters he has undertaken both transactional and disputes work, including resolving claims through arbitration.

Jonathan has more than 35 years of legal practice experience. In 1994, he was awarded the Hudson Prize by the Society of Construction Law for his paper on liquidated damages. He joined Mayer Brown as a partner in 2004.

Spoken Languages

  • English



  • Leading on the English law aspects for a Chinese nuclear power developer as bidder on a project to construct and operate a nuclear power plant comprising two Pressurised Water Reactors with a rating of 1000 MW each, in Eastern Europe.
  • Providing advice to the project sponsor of an integrated gas to power project, including drafting amendments to the EPC contract (based on the FIDIC Silver Book) for a combined gas cycle plant, with ISBL and OSBL elements, as part of an LNG port development project in Brazil.
  • Advising the project sponsor on the contract negotiations and re-stated contract with the incumbent plant supplier for the conversion of a diesel power plant to a hybrid solar powered plant for the Bisha mine in Eritrea.
  • Advising the EPC contractor engaged under FIDIC Yellow Book terms on a complex re-structuring on the contract arrangements including the novation of another EPC contract to bring that within the EPC contractor's scope, in connection with the development of a major automated port facility development in Mexico.
  • Leading the team on an exercise to establish a set of market-standard amendments ‎for the developer of fertiliser process plants to be built/expanded internationally. The exercise included the up-dating of the owner's in-house EPC form and developing a set of amendments to the FIDIC Silver Book as well as up-dating the owner's own procurement checklist and procedures.
  • Advising on a major EPC contract for the expansion and modernisation of a refinery complex for a National Oil Company in South America, with an estimated value of works in excess of US$3 billion, based on the FIDIC Silver Book.
  • Leading on the project contracts for a major petrochemicals complex in Egypt, advising lender group institutions on a series of EPC and related contracts for a Naptha Cracking Unit plus Polyethylene trains, based on bespoke contract forms with total costs estimated in excess of US$10 billion.
  • Advising on the contracting strategy and subsequent procurement by the project sponsor of a US$4.5 billion petrochemical project in the Kingdom of Saudi Arabia. Advice included the drafting and negotiation of the project documentation including EPC contracts (based on FIDIC Silver Book terms for cost reimbursable FEED contracts, converting to Lump Sum for the main process units plus OSBL), the Project Management Contract, on-shore/off-shore versions plus co-ordination agreements for the main construction documents and security documents in the form of Direct Agreements, PCGs and performance bonds.
  • Advising a multi-site national refinery owner on the procurement of bids for a US$1 billion plus expansion and upgrade of its assets, including the drafting of the Project Management Contract and EPC contracts (with conversion mechanisms) and advising on bid bond and performance bonding arrangements.
  • Advising a major oil field services company on a joint venture bid for a US$1 billion plus gas conversion project in Algeria, on its site establishment for a large oil refinery and distribution contract in Uganda and on an EPCI Project for an onshore oil and gas production facility in Turkey.
  • Advising on a significant number of mining developments, including the negotiation of all project documents comprising EPC and EPCM contracts (and hybrid forms), on-shore/off-shore versions and co-ordination agreements, security documents and related construction documentation. Projects include acting for the project sponsors of a €250 million nickel mine project in Turkey and a US$300 million gold/copper/zinc/silver deposit in Eritrea as well as advising a Japanese trading house on the EPCM Contract for the development of the multi-billion dollar Quebrada Blanca Phase 2 project in Chile and acting for the Finance Parties on a US$1.144 billion copper mine project in Baja, Mexico which received the Exploration and Development Funding Award from Mines & Money in 2010. Jonathan also led on the project documents for the lenders on the US$120 million Voskhod nickel mine project in Kazakhstan, which was awarded European Mining Deal of the Year in 2006.
  • Advising a dual-listed gold mining company on its suite of project and contract documents for the development and operation of its assets across a number of West African jurisdictions. The suite of contracts included EPC, EPCM, Contracts for the Supply and Purchase of Explosives, Fuel, Services and Equipment and advising on and drafting contracts for Refining, Underground Automated Mining Systems and Hydro-Electric Power Plants.


  • Acting as co-counsel to a substantial US contractor in an international arbitration arising out of a US$5.4 billion refinery complex in India, conducted under UNCITRAL rules.
  • Advising the project owner on extension of time claims arising out of an EPC contract for the expansion and upgrade of a 730MW combined heat and power facility in the UK.
  • Representing the Buyer under a long-term commodity supply agreement with a Russian producer on claims and subsequent arbitration proceedings and working with co-Counsel to address Russian-law aspects of the dispute, conducted under LCIA rules.
  • Advising the project owner in arbitration proceedings arising out of an EPCM contract for a mining project in West Africa based on the FIDIC White Book.
  • Advising an International Contractor on a series of joint venture agreements and the head EPC contract between the JV Consortium and the Employer in connection with disputes arising out of the procurement, construction, commissioning and completion for a Metro Rail project in the Middle East
  • Advising the monoline insurer on its exposure and rights under a distressed PFI project in the UK with a value in excess of £400m, including advice in relation to court proceedings as to the completion criteria to be applied by the Independent Tester and Events of Default under the finance facility agreements.
  • Representing a Turkish Contractor in connection with claims under an EPC contract for power distribution as part of the Rumaila oil field upgrade and expansion scheme in Iraq.
  • Advising an international contractor on the resolution of its claims arising under an EPC contract for a power plant in connection with the development of the Zubair oil field in Iraq.
  • Advising Lenders on the treatment of an Event of Default in relation to a claim‎ for over US$17m commenced by a contractor on a project in West Africa under a contract based on the FIDIC Red Book.
  • Acting for a major oil field services company on claims and dispute resolution processes related to a North Sea subsea processing facility, a Floating Storage and Offloading (FPSO) vessel in Brazil and a gas processing facility in Kuwait.
  • Representing a UK tunnelling contractor in a series of claims, prosecuted through to adjudication arising out of a multi-billion GBP critical resilience water supply infrastructure project.
  • Acting for the German supplier of specialist underground mining equipment in the successful resolution of a dispute with the owner of a UK mine in Yorkshire.
  • Acting as lead partner on the prosecution of claims for variations, loss and expense and extensions of time on the £1 billion plus mixed-use development at White City, London, working with the contractor's commercial team to achieve satisfactory closure on claims as to time and cost overruns.
  • Acting for a number of major UK contractor companies on the development and execution of their risk management strategies, with a combined portfolio of business in excess of £5 billion annually. Dispute work includes advice on the interpretation of construction contracts, the advancement of claims for entitlement to time and money, the management of defect claims (upstream and downstream) and representation in High Court, arbitration and adjudication proceedings, and as well as via expert determination and mediation processes.
  • Advising a major UK contractor in multi-party proceedings involving claims for alleged defective design and construction works in connection with a retail development, with proceedings in the Technology & Construction Court.
  • Representing a UK contractor in High Court proceedings in the Technology & Construction Court concerning claims in excess of £10m arising under a Term Management Contract for the maintenance of upgrading of facilities.
  • Representing claimants and respondents to adjudication proceedings on a regular basis since the Construction Act came into force in 1999, with involvement in a number of reported enforcement actions including FW Cook Ltd v Shimizu (UK) Ltd (2000), Shimizu Europe Ltd v Automajor Ltd (2002), Beck Peppiatt Ltd v Norwest Holst Construction Ltd (2003), William Verry (Glazing Systems) Ltd v Furlong Homes Ltd (2005) and Multiplex Constructions (UK) Ltd v West India Quay Development Co (Eastern) Ltd (2006).
  • Sitting as an Adjudicator as part of the TeCSA panel and deciding construction disputes under a wide range of schemes, from African LNG port facilities, through to waste to energy plants and commercial developments.
  • Advising a number of Design & Build contractors in the UK on the management of their fire-safety risk liability programmes, following the Grenfell Tower tragedy in 2017. This has included representation in the defence of High Court proceedings in the TCC on a claim valued in excess of £30m, through to advancing complex professional negligence claims via adjudication valued in excess of £8m.


King's College London, University of London, MSc

University of Wales, Cardiff, LLB Hons


  • England and Wales


  • Member of the Editorial Board for LexisPSL Construction
  • Advised CRASH (the property and construction charity for the homeless) on its risk management policies and related corporate governance issues
  • Has advised RedR (engineers for disaster relief) on risk management issues  
  • Member of the Construction & Dispute Resolution Panel of the Chartered Institution of Civil Engineering Surveyors (CICES), 2010 to date
  • Trustee of St Christopher’s Hospice 2010-2012
  • Hosted major fund raising for St. Christopher's Hospice's 40th anniversary in 2007
  • International Bar Association (IBA), with interests in the International Construction Projects Committee and the Mining Law Committee, 2007 to date
  • Society of Construction Law (Council office 1994-2007), member 1990 to date
  • Chartered Institute of Arbitrators (Associate member, 1990 to date)
  • Technology and Construction Solicitors Association (TeCSA), and accredited by TeCSA to act as an adjudicator
  • Chairman of the King's College branch of the Arbitration Club, 1996 to date
  • External tutor on the MSc course in Construction Law and Arbitration at King's College London, 1998 to date
  • Founder member of the Design Build Foundation (now part of Constructing Excellence), 1997
  • Chairman of JCT working group for the development of a multi-party form of appointment for use in the public sector, 2003 to 2007
  • Appointed by the RICS dispute resolution policy committee to serve as a lawyer assessor for re-assessment of RICS registered adjudicators and for chairing appeal panels, 2005 to date

Constantly ranked as a key individual by both Chambers and Legal 500 and other industry guides:

  • Band 2: Construction. Jonathan Hosie handles a broad range of construction mandates spanning both contentious and non-contentious issues. He is adept at advising contractors and sponsors on contractual risk management, front-end procurement and the dispute avoidance aspects of significant commercial developments and energy sector projects. "Jonathan is very business-minded and pays great attention to the changes in the market. He continually and diligently provides support and is very responsive." "Jonathan is hugely experienced and takes good points. He's a wise and authoritative voice." "He's a confident, slick lawyer who is a hard fight on the other side!" (Chambers UK 2023)
  • Listed as a key lawyer, ‘Jonathan Hosie is very responsive and engaged. He understands what we need and delivers it in a timely manner. He has a unique expertise in EPC & FEED & PMC Contracts.’ (Legal 500 2023).
  • Jonathan Hosie handles a broad range of construction mandates spanning both contentious and non-contentious issues. He is adept at advising contractors and sponsors on contractual risk management, front-end procurement and dispute avoidance aspects of significant commercial developments and energy sector projects. "He is extremely knowledgeable and has significant experience in cladding disputes." (Chambers UK 2022).
  • Listed as a key lawyer for Construction. ‘Jonathan Hosie is the best in the legal industry for his knowledge and expertise in claims over construction liability and defects, such as cladding.’ ‘Jonathan Hosie has a wealth of experience and is able to give strategic and helpfully practical advice.’ (Legal 500 2022).
  • Listed under 'Other key lawyers' for Construction and Infrastructure (Legal 500 2021).
  • Jonathan Hosie  handles a broad range of construction mandates spanning both contentious and non-contentious issues. He is adept at advising contractors and sponsors on contractual risk management, front-end procurement and dispute avoidance aspects of significant commercial developments and energy sector projects. "He is a hands-on lawyer with a very calm and pragmatic manner." (Chambers UK 2021).
  • Listed as a 'Leading Individual', Jonathan Hosie is well versed in representing both supplier and purchaser-side clients with regard to the full spectrum of non-contentious construction matters, including contractual risk management, front-end procurement and drafting advice. He is also praised by sources for his strong advice on contentious matters and dispute avoidance. Clients highlight "his ability to manage issues in a strategic way, with a common-sense approach and strong legal backing." (Chambers UK 2020).
  • Listed under 'Other key lawyers' and as a key member of the practice. (Legal 500 2020).
  • Jonathan Hosie is “one of the UK's top construction lawyers,” say sources. He offers a wealth of experience in acting for both supplier and purchaser-side clients, and is highly capable of representing clients in an array of industry sectors. He advises on the full spectrum of construction-related work, including procurement and dispute management. (Chambers UK 2019).
  • Jonathan Hosie’s "expertise rivals anyone within the industry". (Legal 500 2018). 
  • Listed in the Seventh Edition (2018) of The Best Lawyers in the United Kingdom for his work in construction law.
  • Jonathan Hosie is a hugely respected construction practitioner who advises clients on both the purchaser and supplier sides of the market. His broad domestic and international practice spans the spectrum of contentious and non-contentious issues in areas such as power, infrastructure and real estate development. Clients appreciate that he "understands the commercialities" and is a "great thinker." (Chambers UK 2018).
  • Listed and recommended in the 2016, 2017, 2018, 2019 and 2020 Who’s Who Legal: Mining.
  • Jonathan Hosie provides transactional and contentious advice to both purchaser and supplier clients. He advises on big-ticket developments, including power, infrastructure and large office developments. Peers particularly highlight his mining experience. (Chambers UK 2016).
  • Chambers UK 2016 ranks 30 Mayer Brown practices and 47 lawyers. Jonathan is one of only two lawyers in the UK ranked in Chambers 2016 as being in the top Band A for his work in representing both Purchasers (Employers) and Suppliers (Contractors).
  • Key players in the noncontentious team [construction] include Jonathan Hosie (Legal 500 2015);
  • The 2015 London Super Lawyers top 100 list recognised Construction & Engineering partner Jonathan Hosie;
  • Is listed in The International Who's Who of Mining Lawyers 2015;
  • Band 1 for London Construction. Jonathan Hosie is "very experienced and very helpful – he wants to get to the bottom of things and root out the problems quickly," notes a commentator (Chambers UK 2015);
  • The 2014 London Super Lawyers top 100 list recognised Construction & Engineering partner Jonathan Hosie;
  • The "sensible and pragmatic" Jonathan Hosie is an expert in construction-related documentation (Chambers UK 2014);
  • Jonathan is "experienced, knowledgeable and pragmatic", a "meticulous bargainer" (Legal 500 2013);
  • He is "a very good sound lawyer" (Chambers UK 2013);
  • He is admired by sources across the sector, with clients describing him as "exceptional in big disputes" (Chambers UK 2012);
  • "One of the standout lawyers in construction" (Chambers UK 2011);
  • he has "a sharp and analytical mind" (Chambers UK 2010);
  • a "forward-looking, innovative thinker," able to "grasp things quickly." (Chambers UK 2009);
  • Noted for "for keeping his finger on the pulse," (Chambers UK 2008);
  • Clients comment that he is a "smooth and very thorough operator." Peers and clients alike regard Jonathan Hosie as "an unconventional, serious player" (Chambers UK 2006).