In ground-up development, the building is designed to meet the appraisal. In PD conversions, the appraisal fits the building.
Market conditions remain challenging: build costs are elevated, margins compressed and exits harder to underwrite. PD conversion continues to attract attention against that backdrop. Lendhub remains active in the space and continues to fund schemes that are packaged correctly, but the cases that get funded share a common discipline: they start from the building and work outward to the numbers. Brokers and developers should consider addressing the points below when presenting a case to a lender.
The physical envelope
Adequate natural light to habitable rooms is a statutory condition of prior approval, and floor plate depth determines how light reaches them. Deep plates can produce single-aspect units that fail prior approval, or force lightwells that are structurally complex, expensive and reduce Net Saleable Area (NSA). The 2.3m floor-to-ceiling minimum under the Nationally Described Space Standards is a second hard limit, one that older commercial stock can fail to meet once acoustic separation, MVHR ducting and screed build-ups are factored in. Either constraint can, in the worst case, render a scheme undeliverable, or materially reduce achievable unit count. Unit count drives NSA, NSA drives GDV, GDV against the cost stack drives profitability, and profitability drives the leverage and pricing the deal can sustain.
Façade, fire and structural surprises
Layered on top is the façade and life-safety scope. Conversions over 18m, or under 18m where combustible cladding is present, typically require an EWS1 assessment for valuation and mortgage lending purposes. Where the building falls within the Building Safety Regulator gateway regime, programme implications can be significant. Asbestos and non-compliant cladding are typical post-strip-out discoveries, and remediating non-compliant façades often requires internal thermal upgrades that erode NSA. RAAC is also a widely recognised concern: used in UK commercial construction from the 1950s to the 1990s, with a design life of around 30 years and a tendency to fail with limited warning, it sits in the era of stock popular for PD conversion. Identification at due diligence rather than at strip-out is critical. Each of these needs scoping explicitly in the schedule of costs, where applicable.
EPC and warranty challenges
EPC is the next constraint, and increasingly the binding one. Institutional buyers and BTR investors often treat EPC B as a minimum, with MEES expected to tighten toward EPC C by 2030 for residential property. For those considering a sales exit, mainstream mortgage lenders now price and lend differently against EPC ratings, with green mortgage products requiring the higher scores, and a growing reluctance to lend against low-rated stock, which directly affects owner-occupier demand. Term and investment lenders apply the same logic at refinance: poor EPC ratings tend to reduce maximum LTV and raise pricing, and they constrain the ERVs used in deal analysis. Achieving a minimum EPC of B on a converted commercial asset should be ingrained in design from the outset. Warranty selection raises a parallel issue: Lender acceptance of warranty providers varies, with some restricting cover on flats or conversions specifically.
Balancing policy with marketability
These constraints define the boundary within which the appraisal must work. Inside that boundary is the design discretion that determines marketability and exit liquidity. Unit mix, amenity and specification need to match the market demographic and intended exit. PD conversions can suffer a discount of around 5 to 15% to purpose-built equivalents, and getting these decisions right can narrow the gap to ground-up.
We review the aforementioned factors at initial structuring, and applications that address them up front give us the clearest basis to provide the most competitive pricing and leverage we can.
