Hadley Property Group has lodged a planning application to transform the 13.4-acre former GSK headquarters at 980 Great West Road into a high-density, mixed-use neighbourhood delivering about 2,300 homes — including 35% affordable housing — alongside more than 320,000 sq ft of flexible commercial, retail and community space in a reuse-first masterplan.
Hadley Group has submitted a planning application for a 13-acre redevelopment of the former GSK headquarters at 980 Great West Road in Brentford, west London. The proposals aim to deliver around 2,300 homes and more than 320,000 square feet of flexible commercial and retail space, with 35% of housing designated as affordable, according to the lead report. A scoping opinion published by local community sources and planning consultants outlines two principal massing elements for the site, including a tall block around 25 storeys containing roughly 750 flats, 530 student beds and 330 co-living units, plus a second 15-storey block with a further 750 flats and a larger share of commercial space. Access would be via Boston Manor Road and the Great West Road, with around 240 parking spaces on site. These massing concepts accompany a broader vision for a high-density, mixed-use neighbourhood on the 13.4-acre campus.
Industry observers note the scheme’s retrofit-led approach and its multi-tenure planning as a core feature. Turley, acting for Hadley Property Group, has filed the planning submission detailing a mix of Build-to-Rent, co-living and purpose-built student accommodation, with 35% affordable housing and more than 330,000 square feet of flexible commercial, retail and community space aimed at supporting a diverse local economy. The masterplan, developed by Haworth Tompkins, Studio Egret West, DRMM and Metropolitan Workshop, emphasises a reuse-first strategy, reduced embodied carbon, enhancements to public realm and stronger links to riverside parks, alongside a broader ambition to knit the site into Brentford’s urban fabric. Peterson Group’s portfolio materials also flag Hadley’s involvement as a joint endeavour, underscoring the collaboration behind the project as it moves toward formal planning stages.
Beyond the official submission, the project sits within a wider recent timeline for GSK House. Hadley, described as a Peterson Group portfolio company, completed the acquisition of GSK House in Brentford in November 2024, with public consultation and a collaborative Brentford planning process anticipated in 2025. A separate community-forward briefing from local sources outlines a variant massing for the site, suggesting around 2,000 flats across twelve blocks with at least 35% affordable housing, including a substantial component of socially rented homes, together with a significant commercial element and supporting facilities such as play space and community amenities. The design team referenced in these discussions includes a mix of architecture and landscape practices, and the overall objective remains to create an inclusive, sustainable neighbourhood that integrates housing with commercial, charitable, educational and community spaces.
Reference Map:
Reference Map:
Source: Noah Wire Services
- https://www.bdonline.co.uk/news/plans-in-for-2300-home-redevelopment-of-former-gsk-headquarters/5137715.article – Please view link – unable to able to access data
- https://www.turley.co.uk/news/planning-application-submitted-former-gsk-hq – Turley submits planning application on behalf of Hadley Property Group for major retrofit-led neighbourhood at former GSK headquarters in Brentford. Spanning 13 acres, the proposals would deliver 2,300 homes and studio flats, with a mix of tenures including Build-to-Rent, co-living and purpose-built student accommodation. The scheme would provide 35 per cent affordable housing and more than 330,000 square feet of flexible commercial, retail and community space to support a diverse local economy. The masterplan, developed by Haworth Tompkins, Studio Egret West, DRMM and Metropolitan Workshop, emphasises a reuse-first approach, reduced embodied carbon, public realm, and stronger links to riverside parks.
- https://new.chiswickw4.com/page/brentfordtw8/info/congsk010.htm – Developer reveals More Details of GSK House Proposals outlines Hadley Property Group’s forthcoming mixed-use masterplan for 980 Great West Road, Brentford. The plan foresees around 2,000 flats across twelve blocks, with at least 35 per cent designated as affordable housing, including 235 socially rented homes. The scheme also contemplates a substantial commercial component, with about 23,345 square metres of space, plus 7,000 square metres of play space, a GP surgery, pharmacy, and multifaith facilities. The project embraces reuse of the substructure and basement, while creating a pedestrian-friendly public realm and community spaces. Art and biodiversity features are highlighted in visuals.
- https://new.brentfordtw8.com/page/brentfordtw8/info/congsk008.htm – Brentford community site BrentfordTW8 reports that Hadley Property Group’s GSK House redevelopment could feature tall blocks and a mix of residential and non-residential space. A scoping opinion indicates two principal elements: a tall block around 25 storeys containing roughly 750 flats, 530 student beds and 330 co-living units, plus 900 square metres of commercial floorspace and about 2,700 square metres of community space; and a second 15-storey section with a further 750 flats and a larger share of commercial space. Across the 13.4-acre site, access would be via Boston Manor Road and Great West Road, with around 240 parking spaces.
- https://www.petersonhk.com/real-estate/gsk-house-u-k/ – GSK House, U.K. on 980 Great West Road in Brentford is listed by Peterson Group as a 13.4-acre campus-style site acquired in 2024 in partnership with Hadley Property Group. The entry describes plans to transform the former headquarters into an inclusive mixed-use development offering a range of housing options alongside commercial, charitable, educational and community spaces. The project is positioned to contribute to Brentford’s night-time economy and generate local employment opportunities. While specific numbers are not fixed in this summary, the emphasis remains on adaptive reuse and a broadly vibrant, sustainable redevelopment aligned with contemporary urban regeneration objectives for London.
- https://www.petersonhk.com/about-us/news-release/hadley-a-peterson-group-portfolio-company-completes-acquisition-of-historical-gsk-headquarters-in-brentford-west-london/ – Hadley, a Peterson Group portfolio company, completed the acquisition of GSK House in Brentford in November 2024. The release confirms Hadley’s intention to submit proposals for a new mixed-use neighbourhood to Hounslow in 2025. The 13-acre site at 980 Great West Road has stood empty for years, and Hadley, supported by Peterson Group, aims to develop an inclusive scheme featuring housing alongside commercial, charitable, educational and community spaces. A design team including Haworth Tomkins, Studio Egret West, DRMM and McGregor Coxall has been engaged; public consultation is planned as part of a collaborative planning process for Brentford in London.
- https://www.hadley-brentside.co.uk/the-site – The Site page on Hadley’s Brentford project describes the 13.4-acre site and its strategic setting at the junction of key west London routes. It outlines the intention to regenerate the former GSK headquarters at 980 Great West Road into a sustainable, mixed-use neighbourhood with enhanced public realm and community facilities. While the site remains in pre-construction phase and detailed design continues, the emphasis is on stakeholder engagement, mobility improvements and long-term social value. The page also highlights the site’s proximity to Boston Manor Park and the River Brent, and signals Hadley’s commitment to working closely with residents throughout the process.
Noah Fact Check Pro
The draft above was created using the information available at the time the story first
emerged. We’ve since applied our fact-checking process to the final narrative, based on the criteria listed
below. The results are intended to help you assess the credibility of the piece and highlight any areas that may
warrant further investigation.
Freshness check
Score:
7
Notes:
Findings: 
The planning submission referenced is fresh — a planning submission by the project team is publicly reported on 18 August 2025 (Turley) and covered by trade press on 20 August 2025 (Building). ([turley.co.uk](https://www.turley.co.uk/news/planning-application-submitted-former-gsk-hq?utm_source=chatgpt.com), [building.co.uk](https://www.building.co.uk/news/plans-in-for-2300-home-redevelopment-of-former-gsk-headquarters/5137717.article?utm_source=chatgpt.com)). 
However, the narrative is not wholly new: the acquisition of the site was publicly announced on 28 Nov 2024 (Peterson release) and earlier community engagement/scoping material was published in March–June 2025, so large parts of the story have circulated for many months. ([petersonhk.com](https://www.petersonhk.com/about-us/news-release/hadley-a-peterson-group-portfolio-company-completes-acquisition-of-historical-gsk-headquarters-in-brentford-west-london/?utm_source=chatgpt.com), [new.brentfordtw8.com](https://new.brentfordtw8.com/page/brentfordtw8/info/congsk008.htm?utm_source=chatgpt.com)). 
Because substantive elements (ownership, design team, reuse strategy) were disclosed months earlier, the piece is a mix of fresh (planning submission) and recycled/developer-led content (acquisition, masterplan themes). 
Note: several outlets appear to republish developer/consultant material with overlapping wording rather than independent reporting. ([building.co.uk](https://www.building.co.uk/news/plans-in-for-2300-home-redevelopment-of-former-gsk-headquarters/5137717.article?utm_source=chatgpt.com), [turley.co.uk](https://www.turley.co.uk/news/planning-application-submitted-former-gsk-hq?utm_source=chatgpt.com)).
Quotes check
Score:
5
Notes:
Findings: Key quotes attributed to Hadley leadership (for example Andy Portlock’s comment about the acquisition and community ambition) appear identically or very similarly in the developer/owner press release from 28 Nov 2024 and in subsequent coverage — indicating reuse of a corporate statement rather than a new, independently obtained quotation. ([petersonhk.com](https://www.petersonhk.com/about-us/news-release/hadley-a-peterson-group-portfolio-company-completes-acquisition-of-historical-gsk-headquarters-in-brentford-west-london/?utm_source=chatgpt.com), [turley.co.uk](https://www.turley.co.uk/news/planning-application-submitted-former-gsk-hq?utm_source=chatgpt.com)). No unique, verifiable exclusive quotes discovered that first appear in the user-supplied narrative; where wording differs across items (developer release → consultant release → trade press), the variations are minor and consistent with re-publication of the same lines. If the article claimed exclusive interviews or novel quotes, that would be unsupported by the record.
Source reliability
Score:
7
Notes:
Findings: The organisations named and reporting on the story are verifiable and reputable in their spheres: Hadley Property Group / Peterson (owner/developer), Turley (planning consultant), Haworth Tompkins / Studio Egret West / dRMM (architects), and Building.co.uk / local Brentford community outlets (trade / local reportage). ([petersonhk.com](https://www.petersonhk.com/about-us/news-release/hadley-a-peterson-group-portfolio-company-completes-acquisition-of-historical-gsk-headquarters-in-brentford-west-london/?utm_source=chatgpt.com), [turley.co.uk](https://www.turley.co.uk/news/planning-application-submitted-former-gsk-hq?utm_source=chatgpt.com), [drmmstudio.com](https://drmmstudio.com/news-post/regeneration-of-980-great-west-road/?utm_source=chatgpt.com), [building.co.uk](https://www.building.co.uk/news/plans-in-for-2300-home-redevelopment-of-former-gsk-headquarters/5137717.article?utm_source=chatgpt.com)). Caveat: most of the detailed programme figures and rhetoric come from developer or consultant materials (press release, scoping documents, consultation boards) rather than independent investigative reporting — this increases the need for editorial caution because developer materials can present aspirational figures and are optimised for persuasion. There is no evidence that the principal organisations are fabricated; they have established online footprints and corroborating entries.
Plausability check
Score:
7
Notes:
Findings: The core claims (site at 980 Great West Road; 13–13.4 acre site; multi-tenure masterplan; reuse-first/retrofit-led strategy; appointed design team) are consistent across multiple documents and plausible. ([petersonhk.com](https://www.petersonhk.com/about-us/news-release/hadley-a-peterson-group-portfolio-company-completes-acquisition-of-historical-gsk-headquarters-in-brentford-west-london/?utm_source=chatgpt.com), [turley.co.uk](https://www.turley.co.uk/news/planning-application-submitted-former-gsk-hq?utm_source=chatgpt.com), [new.brentfordtw8.com](https://new.brentfordtw8.com/page/brentfordtw8/info/congsk008.htm?utm_source=chatgpt.com)). Discrepancies: reported unit counts vary between versions — local consultation/scoping coverage described ~2,000 flats in 12 blocks (Mar–Jun 2025) whereas the planning submission described as ‘around 2,300 homes’ appears in Aug 2025 coverage; commercial floor area figures also vary slightly between items (320,000–330,000 sq ft vs metric figures in local write-ups). ([new.brentfordtw8.com](https://new.brentfordtw8.com/page/brentfordtw8/info/congsk008.htm?utm_source=chatgpt.com), [building.co.uk](https://www.building.co.uk/news/plans-in-for-2300-home-redevelopment-of-former-gsk-headquarters/5137717.article?utm_source=chatgpt.com)). These shifts are typical as a scheme evolves from scoping/exhibition to formal submission, but they should be flagged to editors as materially important (units, tenure mix, heights). Absence of major contradiction: no reputable outlet disputes ownership or that a submission/scoping has been filed; planned consultation events and a public consultation page are also in evidence. ([hadley-brentside.co.uk](https://www.hadley-brentside.co.uk/consultation?utm_source=chatgpt.com)).
Overall assessment
Verdict (FAIL, OPEN, PASS): OPEN
Confidence (LOW, MEDIUM, HIGH): MEDIUM
Summary:
Summary: OPEN — the narrative is substantially corroborated but primarily driven by developer/consultant materials, so editorial caution is needed. Major facts have multiple confirmations: the acquisition by Hadley/Peterson (announced 28 Nov 2024), scoping/exhibition material published in spring–early summer 2025, and a planning submission reported in mid–late August 2025. ([petersonhk.com](https://www.petersonhk.com/about-us/news-release/hadley-a-peterson-group-portfolio-company-completes-acquisition-of-historical-gsk-headquarters-in-brentford-west-london/?utm_source=chatgpt.com), [new.brentfordtw8.com](https://new.brentfordtw8.com/page/brentfordtw8/info/congsk008.htm?utm_source=chatgpt.com), [turley.co.uk](https://www.turley.co.uk/news/planning-application-submitted-former-gsk-hq?utm_source=chatgpt.com)). Strengths: named organisations, design team and consultation activity are verifiable and reported by trade press and local community outlets — this supports the core credibility of the project. Key risks: much of the text repeats developer/consultant phrasing (quotes and strategic framing) rather than independent reporting, and headline figures have shifted over time (c.2,000 → c.2,300 units; commercial floor areas reported in differing units). Editors should treat the piece as reliable for reporting that a prominent developer has submitted plans and that the scheme has long been under development, but should seek direct confirmation from the Hounslow planning register (application number / documents), the full planning submission on the council portal, or an independent council statement before treating specific figures or tenure breakdowns as final. 
Recommended verification steps: check the London Borough of Hounslow planning portal for the formal application (or scoping opinion SC/2025/0829 referenced in local summaries), request the planning pack from the developer or Turley, and note any differences between scoping material and the final application when publishing. ([beta.hounslow.gov.uk](https://beta.hounslow.gov.uk/planning-building/search-planning-applications?utm_source=chatgpt.com), [new.brentfordtw8.com](https://new.brentfordtw8.com/page/brentfordtw8/info/congsk008.htm?utm_source=chatgpt.com)).
