Everything a property developer needs

Marginly combines deal appraisal, project management, budget tracking, and team collaboration in one focused tool for small UK developers.

Deal Appraisal

Know if a deal stacks in minutes, not hours

Marginly's deal appraisal engine covers every cost in a UK property development deal. Enter the purchase price and the calculator automatically computes SDLT (including the 5% surcharge on additional dwellings), legal fees, broker fees, build costs by project type and m², professional fees, contingency, development finance, and selling costs. Every number updates live as you type.

  • Automatic 2025/26 SDLT calculation with additional dwelling surcharge
  • Build cost presets for light refurb, heavy refurb, conversion, and new build
  • Development finance modelling with LTV, monthly rate, arrangement and exit fees
  • Gross profit, margin on GDV, ROI, and profit on cost
  • Colour-coded health indicator (Strong / Decent / Tight / High Risk)
  • Save up to 10 named scenarios per project
  • Side-by-side scenario comparison
  • PDF export for lenders, investors and JV partners
Estimated Profit
£68,400
Strong
21.4%
on GDV
ROI
26.8%
On Cost
24.1%
Cash In
£97k
Total Cost
£283k
Project Timeline

Keep the build programme on track

Once you've secured a deal, switch to project mode. Marginly's project timeline lets you plan every phase of the development — from exchange through planning, groundworks, superstructure, first fix, second fix, and completion. Set start dates, durations, and milestones. Assign tasks to team members. See the whole programme at a glance on a Gantt-style view.

  • Gantt-style timeline view with phase-level detail
  • Built-in UK development phase template
  • Drag-and-drop task scheduling
  • Milestone tracking with completion status
  • Team member assignment per task
  • Dependencies and critical path
  • Export timeline as PDF
Project Timeline — 4 Birch Lane
Exchange & Purchase
3w
Planning & Design
8w
Groundworks
4w
Superstructure
10w
First Fix
6w
Budget & Spend

Know where every pound is going

Set your budget by category at the start of the project and log every invoice as it comes in. Marginly shows you a running comparison between budget and actual spend across acquisition, build, finance, professional fees, and selling costs. Never be surprised by an overrun again. Drill down into any category to see individual invoices, and flag items that need sign-off.

  • Category-level budget vs. actuals comparison
  • Invoice logging with date, payee, and category
  • OCR invoice scanning — photograph and extract automatically
  • Budget variance alerts
  • Cash position tracking
  • Payment status (paid / outstanding / overdue)
  • Spend reports exportable to CSV or PDF
Budget vs. Actuals
4 Birch Lane
Acquisition£124k / £125k
Build£87k / £168k
Finance£12k / £28k
Professional£16k / £18k
Cashflow Forecasting

See your cash position month by month

Development projects are cash-hungry. Marginly's cashflow forecasting tool models your expected cash in and out for every month of the project. See when you'll need drawdowns from your lender, plan for VAT payments, and make sure you're never caught short. Run scenarios to stress-test your position if the build runs over or sales are delayed.

  • Monthly cashflow forecast for the full project duration
  • Lender drawdown schedule
  • VAT cashflow modelling
  • Sensitivity analysis (build cost overruns, sales delays)
  • Minimum cash balance alerts
  • PDF cashflow report for lender submissions
Monthly Cash Position
Month 1Month 12
Document Vault

Every document in one secure place

Keep all your project documents in a secure, organised vault. Planning consents, building regulations approvals, structural engineer reports, contractor warranties, insurance certificates, land registry documents — everything in one place, accessible from anywhere, searchable in seconds. Never dig through emails looking for a document again.

  • Organised folders by document type
  • Full-text search across all documents
  • Version history on key documents
  • Expiry tracking (insurance, warranties)
  • Share links for specific documents
  • Download all as ZIP
Documents — 4 Birch Lane
📋
Planning Consent
12 Jan 2025 · PDF
🏗
Structural Report
28 Jan 2025 · PDF
📐
Building Regs
03 Mar 2025 · PDF
📄
Contractor Contract
15 Mar 2025 · DOCX
🛡
PI Insurance
01 Apr 2025 · PDF
Team Access

Bring your whole team into the project

Marginly is built for small teams. Invite your project manager, architect, accountant, quantity surveyor, accountant, or JV partner. Set permission levels so each person only sees what's relevant to them. Your PM gets full edit access; your investor gets read-only access to the financials. Everyone stays aligned without endless email chains.

  • Invite team members by email
  • Three permission levels: view, edit, admin
  • Per-project access control
  • Activity log showing who changed what
  • Team notifications for key milestones
  • External sharing links with expiry
Team — 4 Birch Lane
JH
James Hartley
Admin (Owner)
SO
Sarah Okafor
Project Manager
MW
M. Webb Contractors
Contractor (View)
FN
First National Finance
Lender (View)

Ready to try Marginly?

Start with the free calculator — no account needed. Sign up when you're ready to save your deals.