New build first let pricing
Short answer: the standard comparable rental method assumes comparables exist. On a new-build first let they don't. There are no historical rentals at the same address, no track record of how this building lets, and most of the price points available are coming from listings in the same building that have also never been let. The methodology that works builds a price from three triangulated sources rather than one: the developer's own pricing schedule, equivalent-spec rentals in nearby buildings adjusted for floor and aspect, and the same building's earlier completions where any have already let. Anchored against the post-RRA reality that day-one is the price for the life of the tenancy, the method gets to a defensible asking rent that clears without a bidding war — which, since 1 May 2026, is the only lawful outcome anyway.
Why the comparable rental method fails on a new-build first let
The Lettings Valuation Guide §1.3 sets out the standard comparable rental method — "the value of a property is estimated by comparing it to the prices of similar properties rented in similar locations within a recent period of time". The method assumes a market that has already priced similar stock. It works well on established two- and three-bedroom flats in mature lettings catchments because there are dozens of recent comparable lets within a 500-metre radius.
It fails on a new-build first let for three reasons.
No historical lets at the same address. A flat in a freshly-completed development has no previous rental record. Whatever comparable evidence the agent pulls from the immediate vicinity is, by definition, drawn from different buildings, different specifications, different lease structures, and different service-charge regimes. The further from a like-for-like comparable, the more adjustment is required, and adjustment introduces estimation error.
The developer's own pricing schedule is not a market price. When a developer launches a building, they typically publish a pricing schedule across all units, calibrated to maximise total revenue across the building rather than to reflect the price any individual unit would clear at in isolation. The headline rents on the developer's website are negotiable in practice and frequently optimistic. Taking the developer's price as a comparable is reading the listing, not the market.
Same-building comparables are correlated, not independent. Where two or three units in the same building have just let, those let prices reflect the same market window, the same launch marketing, often the same tenant inflows from a single corporate-relocation or institutional source. They are correlated price points, not independent observations. The standard comparable method assumes independence.
The right answer is to use what is available, but use it carefully and triangulate.
Three sources, weighted by context
The methodology we use on new-build first lets builds the price from three sources, weighted differently depending on what evidence is available.
Source 1: equivalent-spec rentals in nearby buildings. Within a 500-1,000-metre radius, what does a comparable specification (square footage, bedroom count, finish level, aspect, floor band) let for in a recently-completed neighbouring development? This is the closest analogue to the standard comparable method. The adjustment work is in matching specifications carefully. A Battersea Power Station two-bed-corner is a different proposition from a Battersea Reach two-bed-mid, even if both are nominally 700 sq ft two-beds within 800 metres of each other.
Source 2: the developer's pricing schedule, read for relative not absolute prices. The developer's schedule across the building is much more useful for what it says about how the developer values one unit relative to another than what it says about absolute rents. If unit 24 and unit 56 are both two-bed-corners and the developer prices them at £3,800 and £4,100 respectively, the differential of £300 reflects the developer's view of the relative desirability of the floor, the aspect, the orientation of the building, the proximity to the lift, the noise from the bin store. That relative information is hard to derive from external comparables and is worth taking from the developer; the absolute number is not.
Source 3: the same building's earlier completions. Where a phased development has already had earlier-phase units let, those let prices are the most directly comparable data available — same building, same managing agent, same head lease, same service charge regime. They are correlated, so they don't substitute for source 1, but they discipline the answer.
Triangulating these three sources gives a defensible asking rent. The triangulation should explain itself: a one-sentence rationale for the rent we'd put in the valuation note, citing which sources weighted how, against which the landlord can sanity-check our reasoning rather than being asked to trust our number.
Why the post-Renters' Rights Act 2025 regime makes this matter more
Under the pre-RRA regime, mispricing a first let was recoverable. If you listed too high you eventually came down; if you listed too low you let quickly and the tenant moved on after twelve months. The fixed-term tenancy gave you an annual reset.
Under the Renters' Rights Act 2025 regime, mispricing is not recoverable in the same way.
The bidding ban (RRA s.56) closes the workaround of "list slightly under and let the market push the rent up". If you list at £4,000 you cannot accept £4,100. The asked rent is the cap on what you can lawfully accept (Essential Terms §22 [RENT-001]). The bidding mechanism that historically corrected a slightly-low first listing no longer exists.
The rent-in-advance ban (RRA s.8) closes the workaround of "let to an international applicant willing to pay six months upfront at a premium". The premium for upfront payment is no longer lawfully chargeable.
The statutory tenant-notice mechanism under PFEA 1977 s.5(1ZA)(a) (as inserted by RRA s.20) means the tenant can give two months' written notice at any time after move-in, including immediately. If the asking rent is too high the property either doesn't let or lets to an applicant who won't actually take it once they've signed — both of which produce a void cost that compounds against the day-one decision.
The Section 13 rent review (HA1988 ss.13, 14, as amended by RRA s.6) means that any increase in subsequent years is capped at "the open market rent the property could reasonably be expected to be let at" and is subject to challenge at the First-tier Tribunal. A first-let rent that's £200 too low produces twelve months of foregone income; a Section 13 increase the following year is capped at open market evidence, so the catch-up has to happen against the same comparable evidence that the first let was priced against. The day-one number compounds.
We've covered this in more depth at the RRA day-one pricing decision and why we won't take the wrong price. The application to new-build first lets is that all three risks — bidding ban, rent-in-advance ban, Section 13 compounding — interact with the comparable-thinness problem in the same direction. The pricing has to be right the first time, and the methodology has to support a defensible answer rather than a hopeful one.
Two factors specific to new-build first-lets
There are two further factors that affect first-let pricing on new-build stock and that the comparable rental method does not naturally capture.
Block-level launch concentration. A new-build building typically launches lettings on multiple units in the same week — sometimes the same day. The internal competition is real. If forty units of comparable specification are advertised at once, the rent that the first units actually let at sets the floor for the remaining units. Where Harvey W James has multiple instructions in the same building, we sequence the launches deliberately, prioritise the units that are best-positioned to clear at our target price, and avoid cannibalising our own listings.
The Four Week Rule timing constraint. Under Lettings Valuation Guide §4, the Four Week Rule states that advertising more than four weeks before the property is genuinely available destroys a listing's prime position by depressing enquiry quality and exhausting the prime portal-search visibility window before the tenant audience that can actually move in arrives. This applies acutely to new-build first lets where the build is "imminent" but legal completion or practical handover is six weeks away. The temptation to advertise from contract exchange — when the marketing materials are ready and the developer is keen to show progress — runs straight into the Four Week Rule. Our practice is to time the marketing launch to the four-week window from the genuine "ready to move in" date, even where this means holding marketing back longer than feels comfortable. See the Four Week Rule and London rentals for the full mechanism.
The check we run before we agree a number
Before we recommend an asking rent for a new-build first let, we run the price through three checks:
Check 1 — the triangulation explains itself. If we can't write a one-sentence rationale citing the three source types (nearby equivalent spec / developer schedule relative differential / same building earlier completions) then the price doesn't have a defensible basis and we're guessing.
Check 2 — the price is internally consistent with the building. A floor-six two-bed should not be priced higher than a floor-twelve two-bed of the same specification. A view-of-courtyard unit should not be priced higher than a view-of-river unit. Internal consistency across the building is what makes the asking rent credible to a tenant audience that will see multiple units in the same building before deciding.
Check 3 — the price clears the Four Week Rule. At this asking rent, in this week, with this property genuinely available within four weeks, do we expect the volume and quality of enquiries that produces a sensible offer within ten days? If not, the price is wrong.
The check is not "what would we list this at if pushed". That's the comparable method's answer to a question the comparable method can't answer well on a new-build. The check is "what number can we defend on the evidence, internally consistent, with a credible let-up timeline?" That answer is the right answer to push.
Where to look next
This post is the fifth in our six-post series on new-build lettings in London:
- What's distinct about new-build lettings in London — the anchor post for the series.
- How utility management works on a London new-build — communal heating, prepayment meters, Bills Included.
- The line between developer snagging and agent maintenance — developer warranty vs. agent procurement scope.
- New-build deposit claim clauses — the tenancy clauses (8.7-8.10) and the wider luxury-compliance stack (HIU/MVHR servicing, fire-door inspections, specialist contractor network) that protect a landlord at deposit adjudication.
- What annual new-build servicing actually costs — a worked example for MVHR plus A/C plus F-Gas leak-check certification on a typical central-London luxury flat.
For the wider day-one-pricing thesis under the Renters' Rights Act 2025, see the RRA day-one pricing decision, why we won't take the wrong price, and the Section 13 rent review process. For the timing rule that disciplines the marketing launch, see the Four Week Rule and London rentals. For the wider operational positioning, see New-Build Specialists.
Sources
- Lettings Valuation Guide v2.0 — §1 Market Appraisal Methodology; §1.3 The Comparable Rental Method; §4 Four Week Rule (Timing Appendix §1); §5.2 What Makes a Home Rent Quickly; line 30 (new-build specialism).
- Essential Terms and Charges v2.1.5 — §22 [RENT-001] marketing price; §41 [RENT-003] Section 13 rent review; §44 New Build Handover & Key Collection.
- Renters' Rights Act 2025 — ss.1 (assured periodic tenancies), 6 (Section 13 amendments), 8 (rent-in-advance ban), 13 (Section 13 process), 20 (tenant notice via PFEA), 56 (bidding ban).
- Housing Act 1988 — ss.13, 14 (as amended by RRA s.6), Form 4A.
- Protection from Eviction Act 1977 — s.5(1ZA)(a) (as inserted by RRA s.20).
- Tenant Fees Act 2019 — schedule of permitted payments.
This post reflects Harvey W James' operational understanding of new-build first-let pricing methodology and the Renters' Rights Act 2025. It is not legal advice. For the published Act text refer to legislation.gov.uk; for your specific situation seek independent legal advice. Last reviewed against Essential Terms and Charges v2.1.5 (7 May 2026) and Lettings Valuation Guide v2.0.