Hounslow Heat Network

Procurement description

Following Cabinet approval in December 2025, the London Borough of Hounslow ("the Council") intends to commence a procurement process in Spring 2027 to select a Heat Network Development Partner ("HNDP") to fund and deliver a district heating network across the borough (the "Hounslow Heat Network").

The Council proposes to partner with the HNDP through a Joint Venture with Golden Share.

Scheme Overview

The Hounslow Heat Network is a borough-wide low-carbon infrastructure programme to modernise and improve the resilience of heat supply across the borough. It is intended to be delivered in phases, starting with an anchor scheme using heat recovery from Thames Water's Mogden Waste Water Treatment Works and expanding in the future to serve public, commercial and residential customers across the borough.

• Scale: the full build-out is expected to supply 484 GWh of annual heat demand through a 69 km network.

• First phase (the reference scheme): 45 GWh annual heat demand through a 9.57km network with anchor loads, including West Middlesex University Hospital and new build and Council-owned assets.

• Funding: the Council has secured £10.55m of Green Heat Network Fund ("GHNF") funding.

• Strategic importance: identified by the Greater London Authority ("GLA") as a strategically valuable heat network area. Hounslow is also part of the National Zoning pipeline, having secured DESNZ funding to form a Zone Coordination Body for the borough and surrounding area.

Who Should Take Part

The Council would like to hear from organisations with experience in the development, financing, construction and operation of heat networks, including those able to bring capital and delivery capability to the project. Consortia are welcome, as are smaller organisations interested in future supply chain opportunities.

Main category

Works

Additional categories

Services

Delivery regions

• UKI75 - Hounslow and Richmond upon Thames

Total value (estimated)

500000000 GBP Including VAT

Contract dates (estimated)

18 April 2028, 00:00AM to 03 March 2032, 23:59PM

Extension end date (if all the extensions are used): 05 March 2040

London Borough of Hounslow

Is the total value above threshold?

Above threshold

CPV classifications

• 09320000 - Steam, hot water and associated products
• 42160000 - Boiler installations
• 42511110 - Heat pumps
• 44622000 - Heat-recovery systems
• 45232140 - District-heating mains construction work
• 45232141 - Heating works
• 45232142 - Heat-transfer station construction work
• 45251250 - District-heating plant construction work
• 45259300 - Heating-plant repair and maintenance work
• 45331000 - Heating, ventilation and air-conditioning installation work
• 50720000 - Repair and maintenance services of central heating
• 65400000 - Other sources of energy supplies and distribution
• 66122000 - Corporate finance and venture capital services
• 71314000 - Energy and related services
• 71321200 - Heating-system design services
• 71334000 - Mechanical and electrical engineering services

Delivery regions

• UKI75 - Hounslow and Richmond upon Thames

Sustainability

Small and medium-sized enterprises (SME)

Voluntary, community and social enterprises (VCSE)

Contract start date (estimated)

18 April 2028, 00:00AM

Contract end date (estimated)

03 March 2032, 23:59PM

Extension end date (estimated)

05 March 2040, 23:59PM

Can the contract be extended?

Yes

Engagement process description

How The Engagement Will Work

The Council will conduct a two-stage preliminary market engagement.

Stage 1 will share details of the heat network and the current reference design work, so that interested parties can explore the opportunity and the Council can obtain feedback on the scheme proposal. It will comprise of a one-hour webinar presented by the Council on Wednesday 18 November 2026 at 12 noon, held online via Microsoft Teams.

Stage 2 is expected to be held in February or March 2027 and will be supported by a more detailed Project Information Document. This stage will include in person presentation, meetings at Hounslow House and a site visit to Thames Water's Mogden Sewage Waste Water Works and West Middlesex University Hospital.

How To Take Part

If your organisation is interested in becoming the Council's Heat Network Development Partner and wishes to take part, please register your interest via the Council's eTendering portal https://procontract.due-north.com/Advert?advertId=cd2c8a30-93d7-f111-8142-6045bdf14b1f&fromProjectDashboard=True by 23:59 on Monday 16 November 2026 where a link is provided to the webinar. Questions may be submitted via the portal before and after the engagement up to the deadline of 23:59 on 4 December 2026. The Council and its advisers will respond via the portal. The webinar presentation, together with an anonymised record of questions, responses and any other relevant information shared during the engagement, excluding information identified as commercially sensitive, will be made available on the portal to all registered parties.

Related Opportunity

The Council is also procuring a partner for a Strategic Energy Partnership ("SEP") to help fund and deliver a diverse portfolio of energy projects and programmes across the borough. A separate preliminary market engagement notice has been published for that opportunity (Portal Ref: DN834966). Organisations may take part in either or both engagements.

Fair And Transparent Engagement

• Taking part in this engagement is not a condition of taking part in any future procurement and will not give any organisation an advantage.

• A summary of the questions, answers and key information shared at each stage will be published to all registered parties via the portal and included in any future procurement documents. Questions will be anonymised and commercially sensitive information will not be disclosed.

The Council is supported by Womble Bond Dickenson (UK) LLP, AECOM and Amberside Advisors. When registering, please declare any relationship with the Council, its officers or its advisers that could give rise to a conflict of interest.

Indicative Timetable

The indicative timetable for the Hounslow Heat Network engagement and procurement is as follows (subject to change):

Stage 1 Engagement

Preliminary market engagement notice published: Tuesday 3 Nov 2026

Registration deadline; webinar invitation and information pack issued: Monday 16 Nov 2026, 23:59pm

Webinar: Wednesday 18 Nov 2026, 12:00

Deadline for submission of questions: Friday 4 Dec 2026, 23:59

Publication of Stage 1 engagement feedback: By Thursday 15 Jan 2027

Stage 2 engagement

Stage 2 in person event including site visit (details to follow): Feb/ Mar 2027

Procurement

Tender notice published with tender documentation: Spring 2027

The Council currently expects to use the competitive flexible procedure under the Procurement Act 2023, including stages of dialogue. The procedure will be confirmed in the tender notice and associated tender documents.

All communications will be via the Council's eTendering portal https://procontract.due-north.com/Advert?advertId=cd2c8a30-93d7-f111-8142-6045bdf14b1f&fromProjectDashboard=True.

_______________________________________________________________

IMPORTANT INFORMATION

This notice is not a call for competition or an invitation to tender and does not bind the Council to carry out a procurement process.

Information provided through this engagement is subject to change and does not represent final decisions or commitments.

The Council and its advisers are not liable for any costs that interested parties may incur in taking part in this preliminary market engagement.

Information submitted may be subject to disclosure under the Freedom of Information Act 2000 and the Environmental Information Regulations 2004. Please identify any information you consider commercially sensitive. Personal data will be handled in line with the Council's privacy notice (https://www.hounslow.gov.uk/privacy-notice).

This engagement is carried out in compliance with sections 16 and 17 of the Procurement Act 2023.

Due date

04 December 2026, 23:59PM

Has the engagement period already ended?

No

Publication date of tender notice (estimated)

19 February 2027