A replicable conversion strategy for landlords, developers and finance teams.

Turning Constraints into Returns

Lucia Piccinini has been invited to contribute to Property Investor News, a UK magazine for professional landlords, developers and finance professionals, known for evidence-led market analysis and practical case studies.

Investors and developers face tighter margins and shifting buyer demand. In this Property Investor News article, Lucia Piccinini presents a replicable office-to-residential conversion playbook drawn from Coomb House in Isleworth, West London. The strategy leverages Permitted Development Rights to de-risk and start quickly, then layers a full planning application to unlock height, façade upgrades and a stronger unit mix translating design choices into measurable ROI. The piece shows how evidence-led due diligence, transport-led demand and local precedent can support massing and accelerated programmes.

For teams screening assets or refining schemes, it highlights where value hides and how to surface it without overspending.

Project Overview: PDR to Full Planning, West London

Coomb House in Isleworth, West London, began as a three-storey, underutilised office block with robust structure, compliant dual escape stairs and serviceable M&E. The investment objective was to deliver a commuter-led residential scheme quickly while creating headroom for a later planning uplift. The team sequenced the project in two phases: first, a Permitted Development Rights conversion securing 39 studio flats to prove viability and start works; second, a full planning application to add two storeys, improve the façade and introduce larger one- to three-bed units. Early strip-out, technical design and Building Control ran in parallel with PDR consent to compress programme risk. Transport connectivity—Isleworth station, bus routes and amenities—supported the target market of young professionals and key workers. Ground-floor parking bays were redesigned with enlarged openings for light and ventilation. The result was a residential-character building with stronger thermal performance, private amenity and a balanced mix aligned to local demand.

Strategy — PDR to Full Planning Stack

Phase one used Permitted Development Rights to convert the existing B1 office into 39 studio flats, establishing viability, securing early cashflow and creating lender confidence without waiting for a full planning committee cycle.

In parallel, the team advanced technical design, building control, strip-out and pre-procurement to compress the programme.

Phase two pursued a full planning application to unlock the structural headroom in the frame: two additional storeys, a residentially legible façade, improved thermal fabric and a broader unit mix including one- to three-bed apartments. This layered approach banked near-term value while positioning the scheme for GDV uplift at exit.

Evidence from local precedents, transport connectivity and demographic demand underpinned increased massing and amenity. Critically, the phased path also preserved optionality should markets shift, the PDR-compliant scheme could deliver; if conditions improved, the planning uplift captured further returns. Stakeholders gained clarity, contractors mobilised earlier, and financing de-risked.

Due Diligence & Local Demand

Before acquisition, the team built an evidence base that de-risked decisions and focused value. Planning history showed a previous hotel consent and a nearby five-storey residential approval, strengthening arguments for massing. Borough housing targets and SHMA data indicated undersupply of smaller units.

Agent conversations confirmed demand from commuters, key workers and young professionals near Isleworth station and bus links.

Catchment analysis mapped schools, amenities and journey times. Early building surveys flagged achievable EPC uplift through fabric upgrades.

Together, these inputs shaped the unit mix, façade strategy and the plan for phasing, and the schedule for parallel design and approvals workstreams.

Why Case Studies Matter and Why to Subscribe to Property Investor News

Reading rigorous case studies is one of the fastest ways for investors to build real-world judgment. They reveal the full stack—context, constraints, numbers, design choices, approvals, risks—so you can recognise patterns, benchmark assumptions and avoid common execution errors. Case studies also sharpen “what if?” thinking: which levers actually move GDV, which upgrades lift EPC at least cost, and how phasing de-risks cash flow. Property Investor News consistently publishes data-led case studies, market analysis and policy updates tailored to active landlords and developers. For investors who want evidence over anecdotes, subscribing ensures a steady flow of actionable insight you can apply on your next appraisal—before capital is committed.

Special Thanks

Heartfelt thanks to Property Investor News and Ross P Bowser for the invitation to contribute and for their thoughtful editorial guidance. Their commitment to clear, evidence-led reporting creates a valuable platform for serious landlords, developers, and finance professionals.

Property Investor News consistently elevates the conversation with rigorous case studies, market analysis, and policy insight—exactly the kind of practical intelligence investors need to make better, faster decisions. I’m grateful for the opportunity to share learnings with their readership and to contribute to that mission.

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As a RIBA Chartered Practice, we work closely with private clients, property developers, and commercial partners—guiding them from concept to completion with innovative, tailored architectural solutions that bring their visions to life.