Property Development Feasibility
Check any property deal in 30 seconds.
28 trades costed. SDLT to the penny. ROI calculated. The feasibility tool UK developers actually use — because it's free, fast, and built by developers.
Total Cost
£287,450
GDV
£356,500
Profit
£69,050
Monthly Rent
£2,850
28
Trades Modelled
11
UK Regions
2,847+
Calculations Run
Built by
Developers, Not Consultants
How It Works
Check any property deal in 30 seconds. Full feasibility report in 5 minutes. No spreadsheets, no guesswork.
Enter the property
Address, asking price, and what you plan to build. Or paste a listing URL.
Get instant analysis
Results in under 30 seconds — not weeks of spreadsheets.
Know your numbers
Full cost breakdown, ROI (pre & post-tax), refinance scenario, and viability verdict.
Why developers switch to SiteMargin
Most developers still use spreadsheets. Here's what that costs you.
Without SiteMargin
- Hours lost in spreadsheets guessing costs
- Missing SDLT surcharges that blow your budget
- No regional build cost data — just guesswork
- Deals fall through because the numbers were wrong
With SiteMargin
- 30-second feasibility check, any deal
- HMRC-accurate SDLT with surcharges built in
- 28 trades costed by region, 3 quality tiers
- Confident decisions backed by real data
What You Get
SDLT Calculator
Standard, additional property, company, first-time buyer. Accurate to HMRC rates.
Build Cost Estimator
Itemised costs by quality tier. Budget, mid-range, or high spec. Regional adjustments.
Financial Model
Mortgage, bridging, refinance. CGT & corporation tax. Post-tax ROI.
Area Analysis
Area classification, comparable sales, recommended development types.
Risk Flags
Flood zones, short leases, high CIL areas, fire safety, EPC warnings.
PDF Reports
Professional feasibility reports for lenders, JV partners, and your own records.
Simple Pricing
Start free. Upgrade when you're ready.
Free
Check the odd deal
- SDLT calculator
- 1 Quick Check / month
- Basic area data
Pro
For active developers running multiple projects
- Unlimited Quick Checks
- Full feasibility reports
- PDF export
- Comparable sales
- Risk flags
- Tax calculations
First 50 members get lifetime Pro access for £199
Business
For firms managing teams
- Everything in Pro
- Project tracker
- Team seats (3)
- API access
- Priority support
A quantity surveyor charges £2,000–£5,000 per project. SiteMargin Pro: £29/mo for unlimited projects.
Ready to check your next deal?
Join UK developers who analyse deals with data, not guesswork.
Quick Check — Free30-second. Free. No sign-up.
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